Talk:List of largest stars/Archive 3

Archive 1

Archive 2

Archive 3

Archive 4

Archive 5

LGGS stars on the list

Hello everyone! I created a wiki account to add the LGGS SGs on the wiki, but i noticed that:

a) There are way too many new stars - 184 of then met the 700+ R_Sun minimum,

b) Some people may not be confortable with the methods i used,

c) Too many equal references were made.

So i'm now gonna clarify the following questions:

- Where did the sizes come from?

- What methods did i use?

- Why there are soo many references?

I used the following to make the list, and the edits Nussun is doing:

- A scientific paper (Specificaly this one: Gordon et al. 2016)

- VizieR (To get the designations and values needed for SBL, aka L/T_eff)

- Micrsoft Excel (To automatically do the SBL calculations, and to convert the VizieR table into a Wikipedia-readable code)

As i outputed the final results, i didnt expect that the code would push the reference count up to 200-something... Oops, sorry! I'm actually new to wiki-coding, so there is that. While the luminosities and the temperatures are real, with the temprature being converted from LogT, the radii were calculated from SBL, aka L/T_eff.

GurrenLagannTSS (talk) 20:43, 29 July 2020 (UTC)

The page is a mess. It needs to be cleaned up. I think edit warring has begun again. We're just back on our feet. I think, from now on, new stars can be put on a waiting list, so, once the list is cleaned up, we can begin adding stars.PNSMurthy (talk) 23:13, 29 July 2020 (UTC)

Update, I have moved the new stars to here. The basic format of the rows hasn't changed, so there will be no problem moving these stars back. From now on, I hope new stars can be placed there until the list is cleaned up and revised.

Thanks! I was going to notify here about the edit, but i guess some people really are hurried on stuff. Again, apologies if the edits were sudden and out of nowhere! GurrenLagannTSS (talk) 23:39, 29 July 2020 (UTC)

Where is Lithopsian? Can we just leave this to him? And many stars here have no references. I especially don't trust the red and black ones. — Preceding unsigned comment added by V255 Canis Majoris (talk • contribs) 20:54, 30 July 2020 (UTC)

I outlined a step-by-step process of how the sizes of those 184 LGGS stars came to be, with references and the methods used. Sure, 2500 RSun does seem insane, but that's what the Wikipedia calculations gave us, using the values given in the VizieR table from Gordon et al 2016. GurrenLagannTSS (talk) 00:48, 3 August 2020 (UTC)

All stars are cited. There's nothing wrong with that. All we need to do is template everything.PNSMurthy (talk) 23:02, 30 July 2020 (UTC)

Wolfram Alpha

https://www.wolframalpha.com/input/?i=largest+star&wal=header Ysku (talk) 08:49, 3 August 2020 (UTC)

WolframAlpha isn't the most accurate place in the world:) Nothing new in the list anyway.PNSMurthy (talk) 09:00, 3 August 2020 (UTC)

What is the radius of HS Cassiopeiae, AZ Cephei, and V411 Persei? Ysku (talk) 09:35, 3 August 2020 (UTC)

That doesn't matter. HS Cas, AZ Ceph and V411 Per have smaller sizes.PNSMurthy (talk) 09:41, 3 August 2020 (UTC)

AZ Ceph is 800 Rsol, HS Cas 500 and V411 Per 600.PNSMurthy (talk) 09:42, 3 August 2020 (UTC)

Case 75

Just to clarify, the Case 75 in Levesque et al 2006 does not refer to AT Persei, but V354 Cephei (even though Case 75 is AT Persei).PNSMurthy (talk) 22:58, 3 August 2020 (UTC)

I am 95% sure Case 75 is V354 Cephei, not AT Persei.JayKayXD (talk) 02:40, 4 August 2020 (UTC)

Really?PNSMurthy (talk) 08:10, 4 August 2020 (UTC)

V354 Cephei is [NBM54] 75, not Case 75. Check Simbad. http://simbad.u-strasbg.fr/simbad/sim-id?Ident=%5BNBM54%5D+75 Nussun05 (talk) 09:50, 4 August 2020 (UTC)

Simbad states AT Persei is Case 75 as well.PNSMurthy (talk) 01:52, 5 August 2020 (UTC)

Progenitors

Are supernova progenitors accepted? - I have found a progenitor (SN 2018fif) that is 1,174 Rsol.

You'd need a new category for how the radius was calculated. And of course the star doesn't exist any more. Lithopsian (talk) 19:43, 4 August 2020 (UTC)

True, but many stars are so distant they might have already gone supernova.PNSMurthy (talk) 23:00, 4 August 2020 (UTC)

@Lithopsian:, a category could be called 'SN' or something.PNSMurthy (talk) 23:00, 4 August 2020 (UTC)

This also brings us to the question of SN 2017eaw. Levesque et all gives a radius of between 1,000 and 2,000 Rsol. Should we put it as 1,500 ± 500 Rsol, or is the margin of error for that star too big?PNSMurthy (talk) 01:53, 5 August 2020 (UTC)

Stick to what the reference says (Levesque et al.?). I don't know which paper you're looking at, but I haven't seen any that say 1,500±500 R_☉, which is a statistical margin of error. Don't do your own averaging, don't assume a margin of error where none is given, don't weight different radius values, just report what is in the reference. Lithopsian (talk) 13:57, 5 August 2020 (UTC)

References

The range was 1,000-2,000 Rsol.PNSMurthy (talk) 22:57, 5 August 2020 (UTC)

Woah

Woah,

In this article, I have uncovered an RSG that is 5,330 Rsol! I think I;ve run to hell and back trying to figure out what to do with it? Should it be added and become the new largest star, or should we all pretend this article never existed?

Please Clarify,

PNSMurthy (talk) 07:51, 5 August 2020 (UTC)

That's VV Doradus. It is most likely a foreground object, a Mira variable not in the LMC. Plenty of other papers about it. Always be wary of largescale databases of machine-calculated data, they should not be relied on as the only source for individual objects because they don't have enough sanity checks. Lithopsian (talk) 14:13, 5 August 2020 (UTC)

So, if a Magellanic Cloud star has a calculated size that's dubious (above 3,000 Rsol or something), can I then assume that is a foreground object no matter what? Nussun05 (talk) 18:50, 5 August 2020 (UTC)

It should certainly make you suspicious. Lithopsian (talk) 19:04, 5 August 2020 (UTC)

No signs of [W60] B90 being a foreground object. Largest known star then? Nussun05 (talk) 19:33, 5 August 2020 (UTC)

Everyone seems to agree that it is a red supergiant in the LMC (not that anybody except Simbad calls it [W60] B90!), although nobody else thinks it is either that cool or that luminous. The 2020 source does give a radius value, but its methods for calculation of the luminosity in particular are crude. Other sources typically give temperatures around 3,400 K and luminosities of 100,000 to 200,000 L_☉. That's the choice you make, go with the consensus of fairly recent papers, none of which actually give a radius, or go with the most recent (gives a radius!) and potentially just be misleading people until someone comes along and publishes a more accurate result. Lithopsian (talk) 20:00, 5 August 2020 (UTC)

I think we should stick with the most recent estimates...PNSMurthy (talk) 22:59, 5 August 2020 (UTC)

Up the limit

This is getting out of hand. There are 200 odd stars in the pending additions page, and 200 more in these three links ; https://iopscience.iop.org/0004-637X/898/1/24/suppdata/apjab9c17t1_mrt.txt, https://iopscience.iop.org/0004-637X/898/1/24/suppdata/apjab9c17t2_mrt.txt, and https://iopscience.iop.org/0004-637X/898/1/24/suppdata/apjab9c17t3_mrt.txt. The list will be 1.), unruly, and 2.), unimaginably long. Over this, we still haven't templated the list yet! How about we amp up the limit to 1,000 Rsol, so we can keep this list relatively large?PNSMurthy (talk) 23:47, 5 August 2020 (UTC)

VY CMa

In the article, a ref states that VY CMa is 2,000 Rsol. Is this for the emission region, or the actual star? I want this clarified before I (possibly mistakenly) amp VY CMa up the list.PNSMurthy (talk) 23:20, 4 August 2020 (UTC)

It is for the star, but it is hardly reliable. They just pluck a random value out of the air to clarify the size of the emission region they're talking about. They don't really care about the size of the star, they certainly don't measure or calculate a value for its radius, just grab something they've probably seen in another paper. Lithopsian (talk) 14:00, 5 August 2020 (UTC)

I see, that means we're sticking with Wittowiski et al?PNSMurthy (talk) 22:58, 5 August 2020 (UTC)

@Lithopsian: Ah yes, it does mention Humphreys et all 2007, Zhang et all 2012, and Wittowiski et all 2012, when measuring VY CMa's Rsol. As far as I'm concerned, the article 1.) Uses other articles' estimates, and 2.) Gives an unacceptable range of 1,500-3,000 Rsol. I'm satsisfied with not using it.PNSMurthy (talk) 00:54, 6 August 2020 (UTC)

WOH S264

According to one estimate, the radius of WOH S264 is 1,149 R_☉ Ysku (talk) 06:28, 6 August 2020 (UTC) https://arxiv.org/abs/1711.07803

It's not the most recent estimate. Nussun05 (talk) 07:11, 6 August 2020 (UTC)

But the 2,555 estimate is based on old data. As it says in the Yi Ren and Bi-Wei Jiang paper 'The stellar parameters, mainly the luminosity and effective temperature, are derived from multiband photometry. We take the Two Micron All Sky Survey (2MASS; Skrutskie et al. 2006) measurement in the J, H, and Ks bands.' The estimate taken from https://arxiv.org/abs/1711.07803 looks at a range of data sources, including newer observations. SpaceImplorerExplorerImplorer (talk) 09:38, 7 August 2020 (UTC)

Alright, I've added the smaller estimate Nussun05 (talk) 10:49, 7 August 2020 (UTC)

LGGS J004539.99+415404.1

"M-004539.99, D-0133312.26, and D-013401.88 (included in full table online) are likely foreground stars." Ysku (talk) 05:05, 6 August 2020 (UTC)

Which stars? What table?PNSMurthy (talk) 05:22, 6 August 2020 (UTC)

If you're talking about the largest Andromeda stars, they don't exactly qualify as foreground because of 1.) They're below the limit of 3,000 (we still haven't gained consensus on that - so far, only Nussun05 agrees with that), and 2.) I believe they are the stars which were previously placed with sizes of 1,980 and 1,870 Rsol.PNSMurthy (talk) 05:24, 6 August 2020 (UTC)

LGGS J004539.99 + 415404.1 is foreground object Ysku (talk) 05:35, 6 August 2020 (UTC)

Please provide a reliable ref. for this Nussun05 (talk) 05:45, 6 August 2020 (UTC)

https://arxiv.org/abs/1707.01916 Ysku (talk) 06:09, 6 August 2020 (UTC)

*https://arxiv.org/abs/1603.0800 Ysku (talk) 06:34, 6 August 2020 (UTC)

*https://arxiv.org/abs/1603.08003 Ysku (talk) 07:23, 6 August 2020 (UTC)

Nope, does not mention the stars. Nussun05 (talk) 07:31, 6 August 2020 (UTC)

That paper has nothing to do with astronomy. Nussun05 (talk) 07:12, 6 August 2020 (UTC)

The paper doesn't mention the stars or anything about a foreground object Nussun05 (talk) 06:25, 6 August 2020 (UTC)

One of the papers does, do I am inclined to believe the star in question isn't a foreground object.PNSMurthy (talk) 08:35, 6 August 2020 (UTC)

Ysku, i'd like to mention that you can edit your own talk page reply. Anyway, yeah, one of the papers does mention it being likely a foreground star. Note the bolding of the word "likely", so unless we are certain that LGGS J004539.99+415404.1 is indeed a foreground star, i'd like if J004539.99 is kept for now. GurrenLagannTSS (talk) 19:09, 7 August 2020 (UTC)

THA 34-26

What is the distance to THA 34-26? Ysku (talk) 10:09, 9 August 2020 (UTC)

Not quite sure. Can't bother to check.PNSMurthy (talk) 11:07, 9 August 2020 (UTC)

Roughly 39000 ly, but it's from a parallax with an error larger than the parallax itself so it's not accurate. — Preceding unsigned comment added by Nussun05 (talk • contribs) 18:21, 9 August 2020 (UTC)

LMC_ID_77

This star was estimated to have a radius of 13,127 R_☉! https://iopscience.iop.org/0004-637X/898/1/24/suppdata/apjab9c17t2_mrt.txt Ysku (talk) 16:53, 8 August 2020 (UTC)

That’s WOH G64 and the size estimate is obviously unreliable. Nussun05 (talk) 16:54, 8 August 2020 (UTC)

The estimate was probably produced using a unreasonably high luminosity based on the surrounding dusk torus.PNSMurthy (talk) 01:49, 9 August 2020 (UTC)

Actually, no. The luminosity is pretty normal for a luminous RSG, it’s the temperature (which is below 1500 K) which is causing the extremely large size. Nussun05 (talk) 03:58, 9 August 2020 (UTC)

That was probably also influenced by the dust torus. The torus probably produced some reddening effect.PNSMurthy (talk) 22:57, 9 August 2020 (UTC)

LGGS J013250.70+304510.6 is foreground object

After checking the spectral type in simbad and the parallax from Gaia DR2, it looks like LGGS J013250.70+304510.6 is actually a foreground Yellow dwarf and not any Yellow super or hypergiant. Nussun05 (talk) 18:09, 10 August 2020 (UTC)

Most likely, but we can't decide that for ourselves. The Drout&Massey paper ranks it as a "possible supergiant", although it derives highly unlikely properties for it. Luckily, Gordon et al (2016) claims it is a foreground "dwarf". Lithopsian (talk) 19:37, 10 August 2020 (UTC)

Probably a foreground and much less luminous and extreme YSG?PNSMurthy (talk) 22:39, 10 August 2020 (UTC)

Full Stops

Alright, I want to clarify something. Should there be, or not be, any full stops at the end of the statements in the notes page? Some statements possess full stops, and yet, others don't. What are we supposed to do. Secondly, should we label stars, for example, like 'RSGC1-F08', as RSGC1-F08 or RSGC1-F08? I've seen a bit of both, and want to clarify this.PNSMurthy (talk) 02:08, 12 August 2020 (UTC)

You mean the notes column in the table? Captions, which these are similar to, should have a full stop if they are a complete sentence, but not if they are just a fragment, for example "Star with the second largest apparent size after the Sun" (currently has a full stop, probably wrongly). Lithopsian (talk) 10:49, 12 August 2020 (UTC)

Sure PNSMurthy (talk) 01:19, 13 August 2020 (UTC)

@Lithopsian: We need to be consistent though. Its better for everything to have full stops (even when its not needed), then for statements which need full stops not to have them, isn't it?PNSMurthy (talk) 01:27, 13 August 2020 (UTC)

The thing we need to be consistent with the is manual of style: MOS:FULLSTOP. Sentence fragments don't have full stops, sentences do. There are other ways to ensure consistency, for example making everything a sentence, but that's never going to be enforceable going forward. Lithopsian (talk) 14:58, 13 August 2020 (UTC)

I see.PNSMurthy (talk) 02:06, 14 August 2020 (UTC)

St2-18 a foreground star?

This article, mentions St2-18 (they mistakenly call it RSGC1-01, but it is in the RSGC2 section, so I assume it is St2-DFK1). It gives it Lbol of 630,000, but also calls it a foreground object. Is this enough to demote St2-18?PNSMurthy (talk) 08:48, 18 August 2020 (UTC)

The reference that gave the large size of Stephenson 2-18 - https://arxiv.org/pdf/1209.6427.pdf - also states that there is a great deal of uncertainty in the distance (pp11-12): "Unfortunately, at this moment, the distance information is based on radial velocities (i.e., distances are estimated by assuming the flat rotation model of the Galaxy). Therefore, the distances could include relatively large uncertainty [relative error of more than 50% according to the recent results of trigonometric parallax measurements; Imai, H., in private communication; theoretically, however, the distances to massive clusters may be improved in the future, because there are independent methodologies to measure the distances to clusters (see, e.g., Perryman et al. 1998; An et al. 2007)]." SpaceImplorerExplorerImplorer (talk) 12:22, 18 August 2020 (UTC)

Also, in the article it is suggesting that RSGC1-01 may in fact be in RSGC2. In Table 8 it gives a luminosity of 335,000, but in the text it revises this to 630,000 if it would be in RSGC2. It is speculation and they don't draw any conclusions, so it would be a matter for further observation to verify. SpaceImplorerExplorerImplorer (talk) 15:46, 18 August 2020 (UTC)

RSGC1-01 is a typo, it should say RSGC2-01, referring to what we call Stephenson 2-18. So table 8 is a different star. The conclusion they draw is "Although these properties do not rule out membership in the cluster, we consider it doubtful." They are not the only authors to draw this conclusion, so we should take good note of it. Lithopsian (talk) 15:52, 18 August 2020 (UTC)

If it was a typo, would it not be listed in Table 7 with the other RSGC2 stars? SpaceImplorerExplorerImplorer (talk) 16:22, 18 August 2020 (UTC)

No, because they think its membership is dubious and, as explained in the text, its observed properties are inconsistent and confusing if it is assumed to be a member (also it isn't in the field of view for their main observations). You're grasping at straws here. Read the paper with an open mind instead of just looking for what you want to see. Look at the references that are given for a sanity check when there appears to be a typo. Or just trust me ;) Lithopsian (talk) 16:52, 18 August 2020 (UTC)

Looking at the references, I would agree that it is a typo, but don't assume what my intentions are. The main point was that the 630,000 luminosity is speculative, so it's irrelevant to the measurement of any star unless confirmed by observation. SpaceImplorerExplorerImplorer (talk) 17:53, 18 August 2020 (UTC)

References

I have not followed the thread fully, but from what I gain - it's not a confirmed FG, right? But we still need to note this?PNSMurthy (talk) 23:01, 18 August 2020 (UTC)

Couple of points; St2-18 is already known not to be in the same field as RSGC2. Its also mentioned as a potential FG object in a few other papers. You don't need to argue about anything...All I believe we should do is note it as a possible FG.PNSMurthy (talk) 04:11, 19 August 2020 (UTC)

So much work

There are still so many more stars from various refs that have yet to be added, I may not always have time or want to add so many, it gets pretty boring. I would like help with this so the list of largest stars can finally be more complete. Let's work together to find as many stars as possible! Nussun05 (talk) 05:47, 6 August 2020 (UTC)

Like I requested above, can we amp up the limit to a 1,000 Rsol?PNSMurthy (talk) 07:05, 6 August 2020 (UTC)

The proposal has been made, now wait for replies (and/or solicit opinions from WT:AST). Primefac (talk) 00:36, 20 August 2020 (UTC)

I will transude a few sections from the talk page there shortly @Primefac:. It seems the proposal has been forgotten in the rush of new questions and statements in this talk page.PNSMurthy (talk) 02:26, 20 August 2020 (UTC)

@Primefac: I have launched my request at WP:AST.PNSMurthy (talk) 02:32, 20 August 2020 (UTC)

Updates

I changed the size of St2-18 to match the lower luminosity because I feel like the 2,150 is just too extreme, and could be an artifact with the K-band or something like that. I also updated some other stars and would appreciate some help updating further. Nussun05 (talk) 18:34, 18 August 2020 (UTC)

VX Sag needs to be downgraded. Other estimates give MUCH smaller sizes.PNSMurthy (talk) 00:54, 19 August 2020 (UTC)

You could do that if you want to. Nussun05 (talk) 05:10, 19 August 2020 (UTC)

Is that the official size for V1943 Sagittarii? This means Stephenson 2-18 isn't the largest anymore. — Preceding unsigned comment added by V255 Canis Majoris (talk • contribs) 13:00, 20 August 2020 (UTC)

What do you mean with "official"?Nussun05 (talk) 18:56, 20 August 2020 (UTC)

Is that the real size of V1943 Sagittarii? Or is it going to get a lower radius soon? Because I don't believe that it would take such a fast amount of time for Stephenson 2-18 to be surpassed by any star. — Preceding unsigned comment added by V255 Canis Majoris (talk • contribs) 17:49, 21 August 2020 (UTC)

A side note

This thread is almost exactly why this page has the problems it does; we're not going on research and data, but "feelings". The last things we should be saying are I feel like the 2,150 is just too extreme and I don't believe that it would take such a fast amount of time for Stephenson 2-18 to be surpassed. We should be saying "is this research valid?" or "of these three sources, which has the best methodology?". There will never be an "official" size for any of these, just peer-reviewed and most-commonly-accepted values based on accepted research practices. What we believe, want, or are surprised by is quite honestly irrelevant. I know not all of us here have degrees in physics and/or astrophysics, but a critical eye is important when reviewing sources. Primefac (talk) 18:02, 21 August 2020 (UTC)

Sometimes I feel the entire list just needs to be remade with sizes from peer-reviewed papers and reliable sources etc. Nussun05 (talk) 18:09, 21 August 2020 (UTC)

Can we just remake the entire list from scratch so it could be a lot better, feels easier than changing it to be honest. This page needs to become a decent and reliable page. Please we need to do this. Nussun05 (talk) 18:14, 21 August 2020 (UTC)

Um... when you say remade with sizes from peer-reviewed papers and reliable sources, that is what we're using. I think almost every reference is a peer-reviewed journal article. What needs "changing"? Primefac (talk) 18:29, 21 August 2020 (UTC)

I just feel the list needs to be remade from scratch..... Please reset it. Nussun05 (talk) 18:31, 21 August 2020 (UTC)

Again, I ask... why? "I just feel" isn't a reason. Primefac (talk) 19:25, 21 August 2020 (UTC)

The list is probably not very accurate but idk......... Nussun05 (talk) 19:27, 21 August 2020 (UTC)

That's why we should be discussing the sources; if one group of researchers uses a single narrow bandwidth to determine T and L, but another group takes an aggregate of a dozen different bandwidths (or doing a meta-analysis of multiple other articles on the same star), the latter will likely be more accurate, but both are just doing the best they can with the data they've been presented. The size of objects in space is a non-trivial value to determine, because (aside from relatively close objects) we don't know exactly how far away they are, if there is any dust/gas getting in the way of the light from that object, etc. Primefac (talk) 19:39, 21 August 2020 (UTC)

I agree. We should not be giving precedence to our opinions. We should be focusing on what the article itself states. We should not be using 'gut feelings'.PNSMurthy (talk) 00:45, 22 August 2020 (UTC)

I agree as well. I myself once thought that stars couldnt get bigger than 2000 RSun, but stars like Stephenson 2-18 proved me wrong. My personal upper hard limit is between 2 and 3 terameters (around 3000 and 4000 RSun), but i wouldnt be suprised if we found an 3k+ RSun star using "accurate" measurments. Personal opinions shouldnt make up the list, but the research must make it at least reliable. GurrenLagannTSS (talk) 14:47, 22 August 2020 (UTC)

3 terameters?! PNSMurthy (talk) 23:26, 23 August 2020 (UTC)

Finish the list

Could someone help me check all the sources for the large stars and add every star above 1000 Rsol from those? Nussun05 (talk) 11:31, 25 August 2020 (UTC)

Certainly. I'm glad a consensus has formed as well.PNSMurthy (talk) 10:23, 28 August 2020 (UTC)

MDFC catalog v2

A year ago Cruzalebes et. al. (https://arxiv.org/abs/1910.00542) provided a large catalog for the angular diameters of stars. This list has added some of the sizes but with almost a million stars in the catalog it's impossible to make sure we didn't miss one. I've extracted the angular sizes and distances from the catalog for stars over 1000 pc away and with an angular diameter of >1 mas, of which there are 24 stars larger than 1000 Rsol. https://docs.google.com/spreadsheets/d/1H1xNE5pEj2bDL06uqNkAJCWawamrtniqz5rVkHUc2I4/edit?usp=sharing

Previously this list used the smallest measurement in the catalog - this is incorrect, as limb-darkening models (which are provided) must be used. Thus the sizes may be 5-10 solar radii larger than the ones calculated in this list

Note that for many of the stars the GAIA parallaxes are noisy and may be bad (TV Gem and W Ind being good examples). I don't make any attempt to correct this (except for a select few where this Talk page had already mentioned them.) I hope this helps in the editing and revision of this page

(edited, as the list has already been cut to 1000 Rsol) Ardenau4 (talk) 20:36, 2 October 2020 (UTC)

Stephenson 2-18 Potentially 1,086 Solar Radii?

A revision from 24 May 2018 shows Stephenson 2-18 with a radius of 1,086 solar radii from Davies et al. 2007. Is this correct or a different star? Faren29 (talk) 01:35, 12 October 2020 (UTC)

A relevant diff showing the removal of that radius, and the article it was based on. Primefac (talk) 01:54, 12 October 2020 (UTC)

Does this mean that the 1,086 solar radii value given was for a different star? Faren29 (talk) 02:16, 12 October 2020 (UTC)

Your guess is as good as mine, since the referenced paper doesn't give a radius for St2-18, or even a temperature and luminosity. That value was added as part of a mass revision by an editor since blocked, and then got rid of because it was wrong. Lithopsian (talk) 11:08, 12 October 2020 (UTC)

Preparations for EDR3

I know EDR3 is somewhat a ways away, but that got me thinking about this article (and Wikipedia in general) will handle it. A lot of the AD-estimates are based off of the revised DR2 parallaxes - it would be scientifically correct to replace these with EDR3, but even without that the AD estimates are already possibly infringing on WP:SYNTHESIS so I'm not sure what will be done here. Looking at it objectively, the MDFC estimates are already WP:SYNTHESIS, even though that's scientifically the right thing to do. Obviously the L/Teff estimates are affected as well but since distance plays a more complicated role in their calculations it's not as easy to correct for that. Thoughts? Ardenau4 (talk) 05:48, 16 October 2020 (UTC)

The values in list should (hopefully!) either be actual published values or calculated from values published in the same paper. If someone (an astronomer even) chooses to combine values derived from different observation sets and then published a value synthesised from them in a WP:RELIABLE source (presumably with some level of peer-review), we should accept that as being properly assessed for its validity. If we do it ourselves, it is WP:SYNTHESIS. We probably don't have the necessary background to assess whether the different data sets are independent or compatible, and even if we do then that calculation won't have any form of review outside of other WP editors. Remember, the guiding principle of Wikipedia is to be WP:VERIFIABLE, not to be "correct". So the immediate effect of EDR3 will be almost zero. Until someone publishes databases or studies using the new distances, we won't have any verifiable data to put in the list. Lithopsian (talk) 13:30, 16 October 2020 (UTC)

Got it, that makes more sense. Ardenau4 (talk) 01:49, 21 October 2020 (UTC)

This is too much

I made a Wikipedia account today to contribute on astronomy pages. And this page was the one that made me. On the pending additions page there are weird stars that are clearly incorrect, hypothetical, with a huge margin of error or fake. Some weird websites found stars up to 13 000 solar radii, clearly fake, and there are stars in the list that have a big marging of error. What are we gonna do about this? --WRMetacat108 (talk) 02:17, 20 October 2020 (UTC)

What websites? Nussun05 (talk) 14:34, 20 October 2020 (UTC)

The pending additions is outdated pretty much, that was back when the page was protected. We only cite the original source, not websites, in this list. Ardenau4 (talk) 01:48, 21 October 2020 (UTC)

(The page is still protected)--WRMetacat108 (talk) 13:14, 21 October 2020 (UTC)

Just to reply to Ardenau4, there is nothing wrong with citing reliable third-party publishers' websites such as Science or Nature; we don't have to use only the primary publications if the website does the hard work (i.e. calculations) for us. Primefac (talk) 15:21, 21 October 2020 (UTC)

Obviously in that case then citing the website is okay (Jim Kaler being an example on this list). Ardenau4 (talk) 17:55, 22 October 2020 (UTC)

Radii from Messineo and Brown paper and other RSG radii derived from Gaia DR2 parallaxes might be unreliable

I have checked the significance values of astrometric noise, and for RSGs almost all of them are above 2. Vizier states that if the significance values of astrometric noise is greater than 2, then the astrometric noise has a significant effect on the parallax, meaning that many of the parallaxes could be unreliable, if so, then radii derived from those parallaxes (like in Messineo and Brown), could be unreliable as well. Nussun05 (talk) 18:10, 7 September 2020 (UTC)

It is the latest estimate. We have no right to question Gaia Dr2 (even if it is incorrect), because that will be our own work. The work will not be based on scientific data. We can't wave of recent estimates like those from Gaia Dr2 until further research (namely the third release), is published.PNSMurthy (talk) 02:21, 8 September 2020 (UTC)

We can’t use the most recent source if it’s not reliable, that’s not how it works. Nussun05 (talk) 04:45, 8 September 2020 (UTC)

How do you know it is unreliable? What proof do you have? What peer-reviewed journal or widely accepted blog publishes this? I'd like those questions answered. We don't know if Gaia is unreliable. Gaia uses the best technology we have. I think, the only way in which we can conclude that Gaia Dr2 is unreliable is when Gaia Dr3 is released.PNSMurthy (talk) 01:51, 9 September 2020 (UTC)

Did you even read my message? I explained exactly why I think it could be unreliable. Nussun05 (talk) 04:25, 9 September 2020 (UTC)

I do not think Vizier can be considered a source.PNSMurthy (talk) 00:13, 10 September 2020 (UTC)

Vizier contains data from the original paper and source, stop this BS now and wait until someone more professional tells their opinions like Lithopsian. Nussun05 (talk) 04:52, 10 September 2020 (UTC)

I don't mind - nor do I care. As long as the list is accurate, and impartial, I'm fine. I just don't want it to be filled with personal opinions and 'correct' data gained from possibly unreliable sources.PNSMurthy (talk) 00:17, 11 September 2020 (UTC)

This isn’t my opinion here, it’s in the vizier table which is the same data as the original paper. For example, check the page of EV Carinae, it says the 574 solar radii size is unreliable because of a high level of astrometric noise. Many other parallaxes for RSGs in Gaia DR2 have similar amounts of noise, making those unreliable as well. Nussun05 (talk) 04:34, 11 September 2020 (UTC)

I see UY Scuti has been reverted to 1708 Rsol. Are all ‘unreliable estimates’ reverted?PNSMurthy (talk) 23:02, 22 October 2020 (UTC)

Naming

I see that in the article, stars in the RSGC1 cluster have been named like RSGC1-F03. If memory serves, weren't stars like this one previously named like this - RSGC1-F03? Should stars in this cluster (at least the ones without their own articles), be named in the latter format?PNSMurthy (talk) 23:24, 24 October 2020 (UTC)

I assume you mean if there's an article on the cluster but not the star. In that case, yes, it would make more sense to link RSGC1-F03 as you have done in your second example above. If the star itself has an article, then we should of course link to it directly. Primefac (talk) 17:38, 26 October 2020 (UTC)

Thank you for confirming.PNSMurthy (talk) 05:10, 4 November 2020 (UTC)

Westerlund 1-26

Although it was 1530 solar radii at the list, when I viewed its personal page, it says 1165 to 1221 solar radii. Is this correct or is this a typo? V255 Canis Majoris (talk) 03:36, 26 October 2020 (UTC)

Westerlund 1-26 has been updated with information from a 2019 PhD thesis. Although the data is arguably good, a thesis is generally not peer-reviewed and not considered as reliable (for WP purposes) as a published journal paper. Might be worth discussing on the article page. Or here, since it affects a number of other stars and some edits have been attempted here. If the data isn't good enough for here, then it wouldn't be good enough for an individual star article either. Lithopsian (talk) 14:55, 26 October 2020 (UTC)

I reverted the edit in question with pretty much that exact rationale (didn't see this thread 'til just now). Primefac (talk) 17:39, 26 October 2020 (UTC)

Nothing has changed. The article of Westerlund 1-26 wasn't revert back to 1530 solar radii. Another thing WOH S281's page stated its size to be 1376 solar radii. I don't know why it was suddenly shifted to 1459 solar radii. HV 888 was reverted to 1300 solar radii because 1765 solar radii was only its largest estimate and not its original size. I also would also like to request MY Cephei to be reverted to 1134 solar radii. The 2061 solar radii is unreliable because it is only the largest estimate and once again, not the exact radius. — Preceding unsigned comment added by V255 Canis Majoris (talk • contribs) 18:20, 5 November 2020 (UTC)

My Cephei is recorded using the most recent estimate, which is probably more accurate then previous ones.PNSMurthy (talk) 04:43, 6 November 2020 (UTC)

Isn't that cherry picking? 2061 solar radii is only its largest estimate. The article needs to be edited. Instead of placing 1134-2061 solar radii, we should just place 2061 solar radii directly. V255 Canis Majoris (talk) 16:42, 6 November 2020 (UTC)

The 1134 was calculated from two different sources. Nussun05 (talk) 12:01, 8 November 2020 (UTC)

New edit issues

As you may see, I made a large number of edits dedicated to updating stars with new sizes, if they weren't included. Unfortunately, this left some mistakes in the refs that you will see at the bottom. I may need assistance on fixing this, as I'm not experienced in this matter. Faren29 (talk) 16:57, 16 November 2020 (UTC)

Possible additions to the list

Are ANY of the stars from Kervella et al. 2019 in this revision legible to be added to the list? Faren29 (talk) 16:15, 18 November 2020 (UTC)

Wrong revision linked? Lithopsian (talk) 16:30, 19 November 2020 (UTC)

It is the correct revision. However, there are numerous stars with radii values given by Kevella et al. 2019 present. I was questioning whether any of these star can be reinstated to the list. Faren29 (talk) 17:13, 18 November 2020 (UTC)

Here's a diff between then and now. Still hard to see just which stars have been removed and which altered. I see:

• V1943 Sgr
• SV Peg
• T Ari
• VX Aur
• U Her
• R Car
• RT Vir
• S Scl

and some more that were below 1,000 R_☉ anyway. None of these stars look much like red supergiants. They are a bunch of Miras and other AGB variable stars. You'll have to make a decision (maybe not just you) between taking the most recent references warts and all, or not. If you want these stars with their highly unlikely values based on Gaia parallaxes that are unreliable by their own standards then you'll have to accept much more credible downsizing for others such as UY Sct and AH Sco. Lithopsian (talk) 21:05, 19 November 2020 (UTC)

V1943 Sagitarii appears in this this revision as one of the star present in Kervella et al. 2019. However, the value presented is much more extreme than any other star in this ref and on list. I would make the assumption that this star stays out of the list? Faren29 (talk) 08:57, 20 November 2020 (UTC)

Certainly, since that is how all other stars with similarly unreliable estimates are trated.PNSMurthy (talk) 07:00, 21 November 2020 (UTC)

IRAS 04509-6922

Can somebody point out how this star got a value in the list at 2249 R⊙? I checked the paper (thesis by Goldman [[1]]) and nowhere did I found any mention of that star's size, radius, or anything whatsoever. It did not get a direct profile of size similar to IRAS 04553−6825: "This RSG is one of the largest known stars, with an estimated radius of 1540 R⊙ (Levesque et al., 2009)" on page 75.

I assume one tries to get the radius by using the table 3.2 at page 64 of the paper since it has the data on luminosity and temperature. But I don't feel that getting the radius out of these raw data would give an honest conclusion as to what the author actually says on the paper. It's getting too far, maybe WP:OR. Furthermore, the paper explicitly states that this star is a new detection, which makes me very skeptical that there is actually a measurement of its radius. Or did I miss something? (I used "Find Page" on the mentions of the star, no mention of any radius whatsoever).

Just wanna be clarified. If one has a justifiable reason in including this star on the list, I would be happy to know. Regards! SkyFlubbler (talk) 02:08, 24 November 2020 (UTC)

The radius of a star can be calculated unambiguously from its bolometric luminosity and effective temperature. The very definition of effective temperature is the temperature which corresponds to the radius of the star, although in many cases it is actually estimated from other observations. This has been discussed extensively and is one reason why a template is used to input the luminosity and temperature. However, the radius is very sensitive to the temperature, and in this case there are two temperatures to pick from. One is an old, potentially somewhat crude, effective temperature from 2005. The other is the effective temperature derived in the thesis itself and labelled T_effDUSTY. T_effDUSTY is the blackbody temperature of the central star as derived from the DUSTY model including the effects of reddening and re-radiation from the surrounding dust. The actual surface of a luminous red supergiant cannot be clearly observed so old direct measurements have tended to be too low because they are measuring, to a certain extent, the surrounding dust. Hence old temperature=2,500 K, new temperature=3,700 K. The new one is a more realistic effective temperature of the photosphere of the star, to the extent that a photosphere can be defined. Lithopsian (talk) 11:23, 24 November 2020 (UTC)

Agreed regarding the template; it gives better information (when looking at the code) to figure out where the numbers come from. If this newer temperature is more accurate, should -6825 be added back to the list? Primefac (talk) 14:28, 24 November 2020 (UTC)

IRAS 04553−6825 is still in the list, as WOH G64. The entry uses the van Loon (2005) effective temperature derived from SED-fitting the optical spectrum. Although only a value in a model, I think the DUSTY "central source" effective temperature is a better representation of the surface temperature of a dust-enshrouded star. This temperature is the one currently in the starbox of WOH G64, although there is also a separate radius from Groenewegen (2017) with an effective temperature comparable to the one in the DUSTY model (not surprising since they use an updated variation of DUSTY). Lithopsian (talk) 16:52, 24 November 2020 (UTC)

Ren et. al. 2020

Can someone add all the stars from Ren et. al. 2020? Nussun05 (talk) 17:18, 19 November 2020 (UTC)

A quick play with a spreadsheet gives these stars above 1,000 R_☉. Some are clearly dubious for various reasons. Many of the rest may already be in the list under different IDs, which could be fun to track down.

SMC_ID_18246	316473	3941	1206.7244356246
SMC_ID_35784	225495	3763	1117.2559249624
SMC_ID_30012	228421	3824	1088.8922125859
SMC_ID_18131	214159	3765	1087.6542192445
SMC_ID_12714	174556	3612	1066.9020564944

LMC_ID_77	375540	1248	13108.4570404547
LMC_ID_324	382557	2843	2549.4529528979
LMC_ID_75	266892	3016	1892.1595259848
LMC_ID_629	283332	3109	1834.6744560861
LMC_ID_173	392442	3442	1761.6460445425
LMC_ID_335	181107	2870	1721.2996073784
LMC_ID_64	266156	3235	1642.3745450098
LMC_ID_707	212979	3172	1528.110216617
LMC_ID_708	166685	3023	1488.4169605627
LMC_ID_474	167624	3051	1465.3329976742
LMC_ID_350	142934	2941	1456.2313273322
LMC_ID_691	263449	3443	1442.5367188
LMC_ID_506	180109	3133	1440.4545593305
LMC_ID_679	80008	2559	1439.0595972878
LMC_ID_355	268371	3493	1414.5661643723
LMC_ID_450	356267	3802	1375.6761821428
LMC_ID_674	144390	3047	1363.5664109026
LMC_ID_46	160656	3138	1356.1110077352
LMC_ID_549	177491	3220	1353.7206991954
LMC_ID_83	289159	3644	1349.1625119842
LMC_ID_715	204144	3344	1346.1343836144
LMC_ID_205	308103	3720	1336.3331089584
LMC_ID_280	249998	3549	1322.5402960889
LMC_ID_711	194400	3341	1315.9755603869
LMC_ID_673	138400	3075	1310.7819419727
LMC_ID_79	181592	3296	1306.8525653356
LMC_ID_253	217719	3462	1297.0200306854
LMC_ID_78	227371	3525	1278.5035495743
LMC_ID_618	252753	3681	1236.1442967585
LMC_ID_117	238065	3659	1214.1591056528
LMC_ID_483	192795	3507	1189.4029090867
LMC_ID_389	183948	3475	1183.2882775502
LMC_ID_317	161710	3371	1178.9722373151
LMC_ID_522	227371	3677	1174.9866196436
LMC_ID_242	186353	3508	1168.696301798
LMC_ID_661	166072	3410	1167.5946458351
LMC_ID_583	140183	3270	1166.5539121911
LMC_ID_528	189643	3527	1166.2996195385
LMC_ID_639	203224	3603	1156.9420821127
LMC_ID_406	206812	3621	1155.5359528417
LMC_ID_208	125654	3201	1152.5756911249
LMC_ID_357	167624	3441	1151.9971365592
LMC_ID_415	193507	3568	1151.2013584959
LMC_ID_509	215743	3668	1150.170826105
LMC_ID_348	161130	3417	1145.3834163098
LMC_ID_704	146129	3335	1145.0624536804
LMC_ID_610	124938	3213	1140.7184568348
LMC_ID_192	178294	3514	1139.2459536385
LMC_ID_591	133014	3280	1129.415215609
LMC_ID_488	186181	3568	1129.199384484
LMC_ID_508	179430	3558	1114.7777344128
LMC_ID_720	179430	3574	1104.8188542436
LMC_ID_653	97601	3071	1103.6214825423
LMC_ID_678	93398	3045	1098.1125099027
LMC_ID_626	114894	3244	1073.0986006355
LMC_ID_718	157593	3525	1064.3950928923
LMC_ID_222	169471	3614	1050.0840077613
LMC_ID_717	130730	3392	1046.9563811834
LMC_ID_259	150209	3512	1046.8672359598
LMC_ID_741	167470	3614	1043.8662553643
LMC_ID_347	142789	3486	1035.9654109848
LMC_ID_410	144523	3510	1028.0326215912
LMC_ID_475	211590	3875	1020.6029056706
LMC_ID_660	143872	3519	1020.4747226108
LMC_ID_12	113966	3320	1020.3851515922
LMC_ID_50	121321	3374	1019.3667863341
LMC_ID_85	169159	3672	1016.2366520989
LMC_ID_425	139938	3507	1013.325436411
LMC_ID_252	114145	3341	1008.3890934588
LMC_ID_688	109229	3318	1000.1585692762

M31_ID_342	381915	3115	2121.8755123636
M31_ID_354	1166440	4485	1788.7883271193
M31_ID_141	137132	2996	1374.4800220655
M31_ID_339	233048	3442	1357.5430258214
M31_ID_217	215250	3427	1316.1215978297
M31_ID_60	300049	3736	1307.4798410787
M31_ID_345	170310	3262	1292.1258230237
M31_ID_349	181051	3414	1216.2590231926
M31_ID_111	213007	3585	1196.3858358623
M31_ID_404	166387	3388	1183.9286690595
M31_ID_293	251081	3775	1171.4551278199
M31_ID_304	367481	4165	1164.2334637301
M31_ID_104	198363	3602	1143.656392444
M31_ID_299	397907	4308	1132.379621861
M31_ID_292	472614	4563	1100.031188164
M31_ID_387	254748	3911	1099.340947271
M31_ID_233	450512	4513	1097.9312832021
M31_ID_118	210945	3747	1089.8578999283
M31_ID_130	156025	3485	1083.5380719583
M31_ID_84	172390	3609	1062.025428986
M31_ID_213	144665	3466	1054.817347977
M31_ID_124	229575	3920	1038.825991798
M31_ID_152	195327	3767	1037.6300591677
M31_ID_385	190855	3780	1018.6402113707
M31_ID_51	79772	3040	1018.1944323503
M31_ID_246	149104	3570	1009.3943275379

Not the prettiest table layouts. Feel free to edit or hide. Lithopsian (talk) 21:42, 19 November 2020 (UTC)

There are clearly some that are highly unreliable. LMC_ID_77 has a radius that seems totally impossible for our current understanding of stars, and LMC_ID_324's radius is also incredibly extreme. The other stats seems more reasonable to place in the list. Faren29 (talk), 13:33, 20 November 2020 (UTC)

Most of the numbers are credible at least, but quite how reliable they are on an individual basis is up for debate. This sort of mass survey is aimed to give statistically-useful results, not individually verified data and especially not for outliers such as the coolest and most luminous examples which may simply be the ones with the largest errors or multiple systems. These sorts of outliers are often excluded when further analysis is done, simply because they are so likely to be incorrect in some way. They might be used if the stars can be cross-matched to known red supergiants that have been identified before. Lithopsian (talk) 14:28, 20 November 2020 (UTC)

I am also curious if any of these stars are already in the list. I would try, however, I'm not entirely certain how to run the SMC and M33 stars through SIMBAD to find out. Faren29 (talk), 14:47, 26 November 2020 (UTC)

Adding all the stars from Ren et al. 2020

Lithopsian laid out the following table of star parameters in Ren et al. 2020 in a previous active discussion:

SMC_ID_18246	316473	3941	1206.7244356246
SMC_ID_35784	225495	3763	1117.2559249624
SMC_ID_30012	228421	3824	1088.8922125859
SMC_ID_18131	214159	3765	1087.6542192445
SMC_ID_12714	174556	3612	1066.9020564944

LMC_ID_77	375540	1248	13108.4570404547
LMC_ID_324	382557	2843	2549.4529528979
LMC_ID_75	266892	3016	1892.1595259848
LMC_ID_629	283332	3109	1834.6744560861
LMC_ID_173	392442	3442	1761.6460445425
LMC_ID_335	181107	2870	1721.2996073784
LMC_ID_64	266156	3235	1642.3745450098
LMC_ID_707	212979	3172	1528.110216617
LMC_ID_708	166685	3023	1488.4169605627
LMC_ID_474	167624	3051	1465.3329976742
LMC_ID_350	142934	2941	1456.2313273322
LMC_ID_691	263449	3443	1442.5367188
LMC_ID_506	180109	3133	1440.4545593305
LMC_ID_679	80008	2559	1439.0595972878
LMC_ID_355	268371	3493	1414.5661643723
LMC_ID_450	356267	3802	1375.6761821428
LMC_ID_674	144390	3047	1363.5664109026
LMC_ID_46	160656	3138	1356.1110077352
LMC_ID_549	177491	3220	1353.7206991954
LMC_ID_83	289159	3644	1349.1625119842
LMC_ID_715	204144	3344	1346.1343836144
LMC_ID_205	308103	3720	1336.3331089584
LMC_ID_280	249998	3549	1322.5402960889
LMC_ID_711	194400	3341	1315.9755603869
LMC_ID_673	138400	3075	1310.7819419727
LMC_ID_79	181592	3296	1306.8525653356
LMC_ID_253	217719	3462	1297.0200306854
LMC_ID_78	227371	3525	1278.5035495743
LMC_ID_618	252753	3681	1236.1442967585
LMC_ID_117	238065	3659	1214.1591056528
LMC_ID_483	192795	3507	1189.4029090867
LMC_ID_389	183948	3475	1183.2882775502
LMC_ID_317	161710	3371	1178.9722373151
LMC_ID_522	227371	3677	1174.9866196436
LMC_ID_242	186353	3508	1168.696301798
LMC_ID_661	166072	3410	1167.5946458351
LMC_ID_583	140183	3270	1166.5539121911
LMC_ID_528	189643	3527	1166.2996195385
LMC_ID_639	203224	3603	1156.9420821127
LMC_ID_406	206812	3621	1155.5359528417
LMC_ID_208	125654	3201	1152.5756911249
LMC_ID_357	167624	3441	1151.9971365592
LMC_ID_415	193507	3568	1151.2013584959
LMC_ID_509	215743	3668	1150.170826105
LMC_ID_348	161130	3417	1145.3834163098
LMC_ID_704	146129	3335	1145.0624536804
LMC_ID_610	124938	3213	1140.7184568348
LMC_ID_192	178294	3514	1139.2459536385
LMC_ID_591	133014	3280	1129.415215609
LMC_ID_488	186181	3568	1129.199384484
LMC_ID_508	179430	3558	1114.7777344128
LMC_ID_720	179430	3574	1104.8188542436
LMC_ID_653	97601	3071	1103.6214825423
LMC_ID_678	93398	3045	1098.1125099027
LMC_ID_626	114894	3244	1073.0986006355
LMC_ID_718	157593	3525	1064.3950928923
LMC_ID_222	169471	3614	1050.0840077613
LMC_ID_717	130730	3392	1046.9563811834
LMC_ID_259	150209	3512	1046.8672359598
LMC_ID_741	167470	3614	1043.8662553643
LMC_ID_347	142789	3486	1035.9654109848
LMC_ID_410	144523	3510	1028.0326215912
LMC_ID_475	211590	3875	1020.6029056706
LMC_ID_660	143872	3519	1020.4747226108
LMC_ID_12	113966	3320	1020.3851515922
LMC_ID_50	121321	3374	1019.3667863341
LMC_ID_85	169159	3672	1016.2366520989
LMC_ID_425	139938	3507	1013.325436411
LMC_ID_252	114145	3341	1008.3890934588
LMC_ID_688	109229	3318	1000.1585692762

M31_ID_342	381915	3115	2121.8755123636
M31_ID_354	1166440	4485	1788.7883271193
M31_ID_141	137132	2996	1374.4800220655
M31_ID_339	233048	3442	1357.5430258214
M31_ID_217	215250	3427	1316.1215978297
M31_ID_60	300049	3736	1307.4798410787
M31_ID_345	170310	3262	1292.1258230237
M31_ID_349	181051	3414	1216.2590231926
M31_ID_111	213007	3585	1196.3858358623
M31_ID_404	166387	3388	1183.9286690595
M31_ID_293	251081	3775	1171.4551278199
M31_ID_304	367481	4165	1164.2334637301
M31_ID_104	198363	3602	1143.656392444
M31_ID_299	397907	4308	1132.379621861
M31_ID_292	472614	4563	1100.031188164
M31_ID_387	254748	3911	1099.340947271
M31_ID_233	450512	4513	1097.9312832021
M31_ID_118	210945	3747	1089.8578999283
M31_ID_130	156025	3485	1083.5380719583
M31_ID_84	172390	3609	1062.025428986
M31_ID_213	144665	3466	1054.817347977
M31_ID_124	229575	3920	1038.825991798
M31_ID_152	195327	3767	1037.6300591677
M31_ID_385	190855	3780	1018.6402113707
M31_ID_51	79772	3040	1018.1944323503
M31_ID_246	149104	3570	1009.3943275379

I need to find out if any of these stars are already present in the list, before adding them. I also need to know which stars stay out of the list, as some could be unreliable or inaccurate. For example, WOH S173 (LMC 77) is listed on the table as 13,108 R_☉, which, to our current understanding of stars, is impossible. Another star on the table, HD 269352 (LMC 342), has a radius of 2,549 R_☉, which is possible for a star to achieve, but is very extreme and very doubtful to me. Another issue is, I do not know how to run the Andromeda Galaxy stars through SIMBAD, with the current IDs I have, which I would use to check if one star is already on the list. I need your assistance with this. Faren29 (talk), 17:40, 26 November 2020 (UTC)

The SMC and LMC source catalogues are available in VizieR. Once you have the record for a star, you can search Simbad for the location by clicking the link at the top of the page. You'll find, surprise surprise that LMC ID 77 is actually WOH G64, not WOH S173. Its a bit labour-intensive and I don't think the IDs are available in the Simbad dictionary of identifiers, so not easy to search by ID.

• SMC source catalog
• LMC source catalog

The M31 source list is available at Ren&Jiang (2019) and includes a cross-reference to LGGS numbers. Again a bit labour-intensive, but it is something. I don't think you'll find many of them in Simbad, but can quickly check if they're in the table already. Lithopsian (talk) 21:03, 26 November 2020 (UTC)

Hearing that LMC_ID_77 is actually WOH G64 is very surprising, however puzzling, as when I enter "MSX LMC 77" into SIMBAD, which is how it seems you enter stars if the identifier contains LMC, it results in WOH S173 showing up. I can do the same format for all LMC stars in this table, however none of the SMC or M31. I'm not experienced with VizieR, so if I can ask for a check if any of these stars are already in the list, that'll be greatly appreciated. Faren29 (talk), 22:27, 26 November 2020 (UTC)

I feel like management of this will have to go into somebody elses hands, as working VizieR is beyond my knowledge and very frustrating. Should we leave out LMC_ID_324 (2,549 R_☉) and possibly M31_ID_342 (2,122 R_☉)? Faren29 (talk), 23:05, 26 November 2020 (UTC)

I've gotten more comfortable in using VizieR, and I can identify the SMC and LMC stars. All I need to know, is a link to the cross reference to Ren & Jiang 2020 with the LGGS numbers, as I don't see it (it's mostly likely staring me in the face, but I'm pretty tired). After that, I can confidently start adding stars (as you can see in latest edits, I've corrected WOH S71 and W60 B90's radius). Faren29 (talk), 23:45, 26 November 2020

Massey et al. 2016

In addition to Ren & Jiang 2020, may I have a table for all stars over 1,000 R_☉ for Massey et al. 2016? I have all values from Gordon et al. 2016 available at my disposal, but I need assistance with this ref. I'm working on all stars from these three refs so I can create a full range of values for all of these extragalactic stars. Faren29 (talk) 02:28, 27 November 2020 (UTC)

According to the data (and I assume we're referring to doi:10.3847/0004-637X/826/2/224 here), there are only a handful of 1000+ stars:

Name	Teff	logL	R☉
J004031.00+404311.1	3850	5.37	1080
J004035.08+404522.3	3750	5.37	1140
J004047.22+404445.5	3775	5.38	1140
J004059.50+404542.6	3850	5.31	1020
J004107.11+411635.6	3800	5.36	1100
J004114.18+403759.8	3900	5.35	1040
J004124.80+411634.7	3725	5.34	1130
J004125.23+411208.9	3825	5.45	1200
J004125.72+411212.7	3750	5.27	1020
J004312.43+413747.1	3725	5.45	1270
J004428.12+415502.9	4200	5.64	1240
J004428.48+415130.9	3850	5.60	1410
J004514.91+413735.0	3800	5.47	1250
J004520.67+414717.3	3775	5.81	1870
J004524.97+420727.2	3625	5.33	1170
J004531.13+414825.7	3775	5.32	1070
J004539.99+415404.1	3675	5.81	1980

If I am not mistaken, these are all in the article already. That being said, if we really have this many extragalactic stars (taking all of the above lists into consideration) it might actually be worth splitting the main article's table into galactic and extragalactic. Primefac (talk) 12:36, 27 November 2020 (UTC)

Thank you for the data, this will be massively helpful in adding to the list. I think splitting the list up like that is a good idea, it's getting very messy. I feel like there should be a key of colours for each galaxy the star is in. One such example would be List of most luminous stars. Faren29 (talk) 13:39, 27 November 2020 (UTC)

I've said it before, but colour-coding violates WP:ACCESS (specifically, WP:DTT). If we have just as many extragalactic large stars as galactic, we might as well just split to a new table. Let's figure out how many stars we have, first. Primefac (talk) 13:42, 27 November 2020 (UTC)

Very well. May I also ask for a table of the LGGS numbers for the M31 IDs in Ren & Jiang 2020, with the radii? I've been attempting this for the past two days to no avail. Faren29 (talk) 14:45, 27 November 2020 (UTC)

Andromeda Galaxy stars

Ren & Jiang 2020
LGGS J004520.67+414717.3: 2,126 solar radii
LGGS J004539.99+415404.1: 1,792 solar radii
LGGS J004124.80+411634.7: 1,377 solar radii
LGGS J004514.91+413735.0: 1,360 solar radii
LGGS J004312.43+413747.1: 1,318 solar radii
LGGS J003951.33+405303.7: 1,310 solar radii
LGGS J004524.97+420727.2: 1,295 solar radii
LGGS J004531.13+414825.7: 1,218 solar radii
LGGS J004047.22+404445.5: 1,198 solar radii
LGGS J004648.83+420418.4: 1,186 solar radii
LGGS J004428.48+415130.9: 1,174 solar radii
LGGS J004438.65+412934.1: 1,166 solar radii
LGGS J004035.08+404522.3: 1,146 solar radii
LGGS J004431.71+415629.1: 1,134 solar radii
LGGS J004428.12+415502.9: 1,102 solar radii
LGGS J004633.38+415951.3: 1,102 solar radii
LGGS J004331.04+411815.9: 1,100 solar radii
LGGS J004059.50+404542.6: 1,092 solar radii
LGGS J004114.18+403759.8: 1,086 solar radii
LGGS J004027.36+410444.9: 1,064 solar radii
LGGS J004306.62+413806.2: 1,057 solar radii
LGGS J004107.11+411635.6: 1,041 solar radii
LGGS J004138.35+412320.7: 1,039 solar radii
LGGS J004632.18+415935.8: 1,020 solar radii
LGGS J003943.89+402104.6: 1,020 solar radii
LGGS J004346.10+411138.8: 1,011 solar radii

Gordon et al. 2016
LGGS J004520.67+414717.3: 2,510 solar radii
LGGS J004539.99+415404.1: 2,377 solar radii
LGGS J004105.97+403407.9: 1,915 solar radii
LGGS J004312.43+413747.1: 1,630 solar radii
LGGS J004125.23+411208.9: 1,602 solar radii
LGGS J004514.91+413735.0: 1,575 solar radii
LGGS J004431.71+415629.1: 1,505 solar radii
LGGS J004428.48+415130.9: 1,504 solar radii
LGGS J004336.68+410811.8: 1,485 solar radii
LGGS J004524.97+420727.2: 1,476 solar radii
LGGS J003951.33+405303.7: 1,425 solar radii
LGGS J004124.80+411634.7: 1,423 solar radii
LGGS J004531.13+414825.7: 1,420 solar radii
LGGS J004031.00+404311.1: 1,383 solar radii
LGGS J004047.22+404445.5: 1,379 solar radii
LGGS J004059.50+404542.6: 1,367 solar radii
LGGS J004125.72+411212.7: 1,359 solar radii
LGGS J004035.08+404522.3: 1,354 solar radii
LGGS J004306.62+413806.2: 1,349 solar radii
LGGS J004648.83+420418.4: 1,346 solar radii
LGGS J004438.65+412934.1: 1,320 solar radii
LGGS J004346.10+411138.8: 1,298 solar radii
LGGS J004632.18+415935.8: 1,265 solar radii
LGGS J004428.12+415502.9: 1,259 solar radii
LGGS J004114.18+403759.8: 1,249 solar radii
LGGS J004148.74+410843.0: 1,248 solar radii
LGGS J004633.38+415951.3: 1,229 solar radii
LGGS J004416.28+412106.6: 1,222 solar radii
LGGS J004107.11+411635.6: 1,207 solar radii
LGGS J004027.36+410444.9: 1,201 solar radii
LGGS J004506.85+413408.2: 1,194 solar radii
LGGS J004503.35+413026.3: 1,174 solar radii
LGGS J004304.62+410348.4: 1,171 solar radii
LGGS J004047.82+410936.4: 1,167 solar radii
LGGS J004138.35+412320.7: 1,159 solar radii
LGGS J004347.31+411203.6: 1,143 solar radii
LGGS J003942.92+402051.1: 1,133 solar radii
LGGS J004731.12+422749.1: 1,121 solar radii
LGGS J004451.76+420006.0: 1,116 solar radii
LGGS J004219.25+405116.4: 1,103 solar radii
LGGS J004253.25+411613.9: 1,099 solar radii
LGGS J004124.81+411206.1: 1,094 solar radii
LGGS J004415.76+411750.7: 1,084 solar radii
LGGS J004447.74+413050.0: 1,083 solar radii
LGGS J003943.89+402104.6: 1,076 solar radii
LGGS J003811.56+402358.2: 1,060 solar radii
LGGS J004030.64+404246.2: 1,060 solar radii
LGGS J004631.49+421133.1: 1,060 solar radii
LGGS J003942.42+403204.1: 1,057 solar radii
LGGS J004346.18+411515.0: 1,057 solar radii
LGGS J004638.17+420008.9: 1,056 solar radii
LGGS J004501.30+413922.5: 1,054 solar radii
LGGS J003910.56+402545.6: 1,042 solar radii
LGGS J003912.77+404412.1: 1,037 solar radii
LGGS J004507.90+413427.4: 1,034 solar radii
LGGS J004406.60+411536.6: 1,033 solar radii
LGGS J004120.25+403838.1: 1,021 solar radii
LGGS J004108.42+410655.3: 1,021 solar radii
LGGS J004607.45+414544.6: 1,018 solar radii
LGGS J004305.77+410742.5: 1,015 solar radii
LGGS J004424.94+412322.3: 1,013 solar radii
LGGS J004415.17+415640.6: 1,008 solar radii
LGGS J004118.29+404940.3: 1,005 solar radii

Massey et al. 2016
LGGS J004539.99+415404.1: 1,980 solar radii
LGGS J004520.67+414717.3: 1,870 solar radii
LGGS J004428.48+415130.9: 1,410 solar radii
LGGS J004312.43+413747.1: 1,270 solar radii
LGGS J004514.91+413735.0: 1,250 solar radii
LGGS J004428.12+415502.9: 1,240 solar radii
LGGS J004125.23+411208.9: 1,200 solar radii
LGGS J004524.97+420727.2: 1,170 solar radii
LGGS J004035.08+404522.3: 1,140 solar radii
LGGS J004047.22+404445.5: 1,140 solar radii
LGGS J004124.80+411634.7: 1,130 solar radii
LGGS J004107.11+411635.6: 1,100 solar radii
LGGS J004031.00+404311.1: 1,080 solar radii
LGGS J004531.13+414825.7: 1,070 solar radii
LGGS J004114.18+403759.8: 1,040 solar radii
LGGS J004059.50+404542.6: 1,020 solar radii
LGGS J004125.72+411212.7: 1,020 solar radii

Above is every single radii value of RSGs from the Andromeda Galaxy. I figured out how to access cross-refs. The same star may appear in all three lists, and the full range of radii may already appear in the list. For stars that aren't, take the smallest value then the largest tp create a full range in radius for that specific. I will be taking a break, as I'm burnt out. Faren29 (talk) 17:34, 27 November 2020 (UTC)

Gaia EDR3

I've heard that Gaia EDR3 released today, and I saw that there's new RSG parallaxes, I'm so excited for new papers with radii. Nussun05 (talk) 17:30, 3 December 2020 (UTC)

UY Scuti as quoted by Cruzalébes et al. 2019

UY Scuti has a radius of 948 solar radii, based on a distance of 1,526 pc and an angular diameter of 5.779 mas, in Cruzalébes et al. 2019. Should I add this value or is it too noisy and keep the radius given by Arroyo-Torres et al. 2013? Faren29 (talk) 13:27, 6 December 2020

What's the error on that value? Primefac (talk) 14:12, 6 December 2020 (UTC)

It was in a spreadsheet made by Ardenau4 (credits to him): https://docs.google.com/spreadsheets/d/1H1xNE5pEj2bDL06uqNkAJCWawamrtniqz5rVkHUc2I4/edit?usp=sharing, but it isn't highlighted in red since it was below 1,000 solar radii. I'm not sure how to work the table, since it is absolutely ginormous. Faren29 (talk) 14:43, 6 December 2020

That spreadsheet does not have errors on it. Primefac (talk) 14:53, 6 December 2020 (UTC)

Indeed, Ardenau4 did state he did not include the errors. Therefore, the errors will be located in the actual catalogue. However, I'm not sure how to find it UY Scuti without scrolling through nearly half a million stars. Faren29 (talk) 15:07, 6 December 2020

5.779±0.553 mas. You would also want to consider the margin of error on the distance. Bailer-Jones gives a lower bound of 1,297 pc and an upper bound of 1,850 pc. You can't really work those into a single statistical margin of error for the radius, but it will give you an idea of the statistical errors involved, possibly ±20%. There are other sources of error but those are harder to quantify. Lithopsian (talk) 16:31, 6 December 2020 (UTC)

Is this atleast in the bounds of a reliable parallax? This has got me considering whether it should be added or not. Faren29 (talk) 01:44, 9 December 2020

V425 Carinae

V425 Car is an extreme M9 AGB-star, and it has a luminosity of 150,000 L_☉, maybe it could be one of the largest known stars? Nussun05 (talk) 14:45, 6 December 2020 (UTC)

Perhaps, but a paper from over 30 years ago? I don't think that is reliable anymore, simply too much has happened between that date and now. Faren29 (talk) 14:53, 6 December 2020 (UTC)

Yeah, I'd like if someone checks some of the newer papers Nussun05 (talk) 15:21, 6 December 2020 (UTC)

I don't think we should include such dubious AGB stars in the list. 99% of articles catalogue AGB stars as between 50 and 350 solar radii. It seems a little dubious for stars of the like to be well above the previously mentioned range. I think we should only include such AGB stars if two articles both consider similarly sized values for their solar radii.PNSMurthy (talk) 08:42, 9 December 2020 (UTC)

I almost feel like we need to have two references for every star, if not two values that are identical at least two values that are within a few hundred R_☉ of each other. Primefac (talk) 11:24, 9 December 2020 (UTC)

Thats a good point, though many RSG stars are present in only single papers (since they have not attracted the eye of science). It would be biased to leave potentially large RSGs out of the list. I feel that this treatment should only be for AGBs, since they tend to not exceed 400 solar radii. PNSMurthy (talk) 02:47, 10 December 2020 (UTC)

References

Wdym Primefac? Nussun05 (talk) 19:12, 11 December 2020 (UTC)

3/4 of the conversations on this talk page are "is this source reliable?" While I feel that these are productive discussions, but if we can have two corroborating sources (and not just Source B saying "according to Source A") it makes the information more likely to be accurate. Primefac (talk) 13:54, 12 December 2020 (UTC)

The upper luminosity limit for AGB stars is considered to be at 60,000 L_☉ and the luminosity of this star just like most AGB and supergiant stars is most likely much lower. After all, that reference doesn't give the star a temperature. 88.121.235.196 (talk) 21:44, 12 December 2020 (UTC)

Implementing this would remove 99% of the stars suggested...PNSMurthy (talk) 02:27, 13 December 2020 (UTC)

Unlikely, though it was just a suggestion. Primefac (talk) 20:47, 13 December 2020 (UTC)

MY Cep

Should MY Cep be at 2,061 or 1,134? 2,061 is more recent but someone is trying to argue that "it's only 2 years newer" or something. He tried talking about it on my talk page instead of here so I'm bringing it here to see what everyone else thinks. JayKayXD (talk) 16:25, 28 November 2020 (UTC)

Why are you still so reluctant to keep MY Cephei where it should be? I don't see you complaining about any other star that has a slightly older, but smaller radius (or hell, there are higher values, that are still older, in the radius boxes as well, I don't see them being removed). Why just MY Cephei? I'm really starting to believe, that this is just for a star that you personally favor. There is no need to bring this discussion here, considering you are the only one who is still complaining about where MY Cephei is placed. Faren29 (talk) 19:07, 28 November 2020 (UTC)

I have heard your opinion already. I've replied to you on my talk page. Please read that before you read this. Lithopsian undid your edit twice and before you whine about him again, he has been cleaning crap from this article for god knows how long so if you have a problem with him, that's probably on you. This article has been going by most recent ref for each star unless there's a good reason not to. It's been that way at least since I've been an editor but still, I was the bigger person in this situation because I stopped the edit war and was willing to talk to you instead. Now, I've already heard your opinion. I'm trying to hear other people's now, not yours again, thanks.;) JayKayXD (talk) 16:12, 29 November 2020 (UTC)

Honestly I think MY Cephei should be in the latter. The newest source shouldn't always be taken, especially if its new by a relatively small margin. Generally it would be more cautious to go with a smaller and relatively new estimate, then to go with an unusually large one.PNSMurthy (talk) 07:51, 16 December 2020 (UTC)

MY Cep Lbol

Beasor et al. 2018 states a bolometric luminosity of 5.19 ± 0.07. However, I'm struggling to find out if this is logL or just the value x 10^5. This because luminosity of 10^0.07 is only 1.175, which doesn't even seem worth including. Faren29 (talk) 13:40, 20 December 2020 (UTC)

It's probably log L.PNSMurthy (talk) 09:41, 22 December 2020 (UTC)

Kamath et al. 2015

https://cdsarc.unistra.fr/viz-bin/cat/J/MNRAS/454/1468 This paper needs to be investigated. This is the paper that gave HV 888 a radius of 1,477 R_☉ based on a luminosity of 295,000 L_☉ and an effective temperature of 3,500 K. Can I have a table of all the stars above 1,000 R_☉? — Preceding unsigned comment added by Faren29 (talk • contribs) 22:13, 22 December 2020 (UTC)

This is long overdue

Well, it seems that the stars V1943 Sagittarii, SV Pegasi and V744 Sagittarii were taken off the list by a fellow editor, but I now request that we take WY Velorum A, RX Telescopii and V538 Carinae off the list as well. The radii are all based on data from Gaia Data Release 2, and all parallaxes contain a significance of astrometric excess noise well above 2, which VizieR states anything above 2 has a large effect on the parallax and is considered potentially unreliable. The significance of astrometric excess noise for WY Velorum A, RX Telescopii and V538 Carinee, is 1.61e+02, 3.56e+01 and 2.87e+01 respectively.

The radius of RX Telescopii was taken out of the article recently which leads me to believe if it isn't reliable enough for the article, it's not reliable enough for the list. To add insult to injury, V538 Carinae is not even really considered a supergiant star; more of an asymptotic giant branch star and long-period variable candidate. Plus it's not like the value of 580 R☉ for V538 Carinae is any better; the margin of error for the distance is much larger than the distance itself.

Now, Skinner and Whitmore 1988 does give a radius of 1,700 R☉ for WY Velorum A, along with radii for some other supergiants, but this paper is highly old. This paper also gives radii for other stars, that is simply just too large for the standards of now. For example, this paper lists VY Canis Majoris with an incredibly ridiculous radius of 9,300 R_☉. This leads me to conclude, that these stars be taken off for the time being. Faren29 (talk) 18:16, 24 December 2020 (UTC)

Would seem to be something of a follow-on to the discussion about what sources are sufficient to be on the list. More critically, what sources are sufficient to be near the top of the list? Exceptional claims require exceptional sources. The linked section is short, but the key point for us is: "Any exceptional claim requires multiple high-quality sources". We may be able to stretch things a little because of the subject matter, maybe one peer-reviewed in-depth study of a star taking into account previous published research could be acceptable A single entry in an unfiltered computer-generated database, especially one producing an unlikely or exceptional result, perhaps isn't acceptable. Lithopsian (talk) 20:19, 24 December 2020 (UTC)

Stars without their own articles

I really hate those stars who are highlighted in red and black. I wish they would just go away. By the way, why did VY Canis Majoris return to 1420 solar radii? — Preceding unsigned comment added by V255 Canis Majoris (talk • contribs) 06:47, 25 December 2020 (UTC)

Returned would be a bad choice of words, the radius given by Wittkowski et al. 2012 was always more accurate, and I just recently found a new paper in 2019 that referenced the radius. Merry Christmas. Faren29 (talk) 11:26, 25 December 2020 (UTC)

We can't really remove stars that are red or black, since that would take away the relative completeness from this list. We should not be biased to remove relatively unknown stars.PNSMurthy (talk) 11:57, 27 December 2020 (UTC)

I would suggest that the redlinks all deserve to be looked at critically. The wikilink implies that the star is notable and could have its own article one day. If not, it shouldn't be wikilinked and presumably shouldn't even be in the list. If stars are in the list and not considered notable, then the list should be pruned. Again, consider whether the evidence for some of these stars is too thin for them to be considered notable, and by extension too thin to put them in the list at all. Lithopsian (talk) 16:10, 27 December 2020 (UTC)

I don't view notability of these stars as criteria for their addition to the list, it's not a popularity contest. Faren29 (talk) 22:11, 27 December 2020 (UTC)

Some stars are not arranged properly because the red and black ones are too many. V255 Canis Majoris (talk) 23:35, 27 December 2020 (UTC)

Please review the whole list. Even the numbers are not sequenced properly. The star below SMC 18136 is 1320 solar radii and look at the stars with 1248 and 1250 solar radii. The stars with 1121 and 1122 solar radii are above the stars with 1129 solar radii. RSGC1-F05 and the star above it are supposed to switch positions due to the other star possessing a lower radius.

I also want you to consider the fact that the sizes of the blue links change from time to time which may prove that most of their sources can either change or be unreliable. Let alone the red and black ones. You barely know these stars. Otherwise, they would already have been given their own articles. — Preceding unsigned comment added by V255 Canis Majoris (talk • contribs) 23:47, 27 December 2020 (UTC)

I disagree with you Lithopsian. This list is called the list of known largest stars for a reason. It doesn't just include well known stars, but all known stars that have a reliable source. It would be favoritism to simply keep 'famous' stars. It seems discussions like this keep on coming up, and yet nothing goes anywhere. This sort of discussion seems to be quite monotonous, since it brings up the same topic over and over again, and no one ever looks at it.PNSMurthy (talk) 05:39, 28 December 2020 (UTC)

Yeah that's right. this is list of largest stars not list of largest famous stars Tc06cimaron (talk) 13:19, 28 December 2020 (UTC)

So be it. If you all say it isn't a popularity contest then you need to stop treating it like one. Isn't being "one of the largest known stars" notable? If not then the list is probably too long. Regardless, any stars that are not notable should not be wikilinked because they aren't going to get an article. Redlinks should only be shown for stars that could/should have their own article but haven't yet. Several stars in the list have already had articles deleted or redirected to this list. Lithopsian (talk) 14:43, 28 December 2020 (UTC)

I'm sorry, but I always thought "one of the largest stars known" meant it was one of the largest stars discovered. Perhaps "one of the largest stars known" is a rather ambiguous term, since in this context it can mean if it is one of the largest stars that is well-known or it can mean it's one of largest stars that has been discovered. I have always viewed it as the latter. Faren29 (talk) 18:38, 28 December 2020 (UTC)

Lithopsian, how about the black ones? The stars from other galaxies like Andromeda and Triangulum? Should they be included? V255 Canis Majoris (talk) 20:43, 28 December 2020 (UTC)

A large star is a large star. We can decide whether or not it is likely to be notable (i.e. "red" or "black") but its inclusion on this list is based on size, not notability. Primefac (talk) 20:47, 28 December 2020 (UTC)

I feel 'largest stars known' is as precise as needed. I don't see how it can mean one of the largest well known stars, and even if it does, that doesn't really matter, since one of the largest well known stars (atleast in the situation of this list), would also be up there with the largest known stars, since any star larger than 1,000 solar radii is generally considered one of the largest known stars.PNSMurthy (talk) 04:45, 29 December 2020 (UTC)

The validity of Jones, Olivia C.: et al. (September 2017)

I'm beginning to question the validity of the star radii suggested in this paper. Most RSGs in this paper have this size from ridiculously low temperatures that are far beyond reasonable for any large star (2,673 K is repeated alot). An example of this: VV Doradus, while not listed as an RSG in the paper, is near the bottom of the table with a listed temperature of 2,673 K, and two bolometric magnitudes of –10.04 and –10.74. Obviously suggesting ridiculously high luminosities, this leads to a radius of 4,214–5,816 R_☉. I look at this and I'm instantly in doubt. This paper appears as a reference for two stars on the list, IRAS 05346-6949 and HD 270422. Any other opinions? Faren29 (talk) 23:33, 9 January 2021 (UTC)

I don’t think it’s very reliable. Also, we should decide what extragalactic star papers use the most accurate methods to derive luminosity and temperature, then we make a list to prioritize them in the right order, and update the list based on that. We could also cross-check with many different sources for each star and select the smallest estimate, but that could take a long time. Nussun05 (talk) 09:00, 10 January 2021 (UTC)

We've gone over this. Any star with outrageous parameters should not be included. I also believe VV Doradus was a foreground giant. Also, the smallest estimate isn't always the most accurate one, and many stars don't have more than one estimate.PNSMurthy (talk) 02:31, 11 January 2021 (UTC)

Groenewegen et al. 2018

VV Doradus: 6,599 solar radii
UY Doradus: 6,386 solar radii
RS Mensae: 4,623 solar radii
HD 271832: 4,073 solar radii
WOH G17: 2,955 solar radii
HD 269924: 2,220 solar radii
WOH S450: 1,896 solar radii

The top five of these stars are most likely foreground objects, but how about HD 269924? It is only a little bigger than Stephenson 2-18, and WOH S450 also looks legible to go into the list. This has likely been asked before, but I'm just checking. Faren29 (talk) 00:44, 1 December 2020 (UTC)

I feel like they would have remarked on a star that's 6600 R_☉. Meanwhile, their "super AGB" star, "MSX SMC 055 (or IRAS 00483−7347)" comes in at just 1,557 R_☉ (which probably should be added to the table). Primefac (talk) 15:15, 1 December 2020 (UTC)

I think it states those stars are likely foreground objects. I'm just unsure about HD 296924, as its size is not as extreme as the others. Faren29 (talk) 15:18, 1 December 2020 (UTC)

They're all fairly obvious giants, not supergiants and so probably not as big as indicated. I haven't checked the paper to see if they remark on these stars themselves. Lithopsian (talk) 15:23, 1 December 2020 (UTC)

I only looked for VV Dor, but the only places it is either listed or mentioned are in the tables (pg 18 A.2, pg 20 B.2), and explicitly listed as a foreground object in A.2. Primefac (talk) 15:27, 1 December 2020 (UTC)

Should I remove WOH S450 from the list? That star is on the list as 1,896 R_☉. Faren29 (talk) 16:09, 1 December 2020 (UTC)

WOH S450 and HD 269924 are both flagged in the paper as foreground objects. This paper shouldn't be used as a source to support the radii given in the tables since they are not considered to be correct by the authors (or the algorithm that churned out the tables). Lithopsian (talk) 16:27, 1 December 2020 (UTC)

Isn't HD 269924 already present in the list?PNSMurthy (talk) 08:20, 2 December 2020 (UTC)

True. 2600 solar radii is the upper theoretical limit for a star. Though Shadron Soul and VY Masses Majoris are fake stars, I want to point out that most of the stars here are larger than Shadron Soul and the two stars from Dorado are not very far behind VY Masses Majoris nor the Quasi Star's size. These are unreal sizes. V255 Canis Majoris (talk) 13:31, 18 January 2021 (UTC)

Discord server for managing the list

Hi, I made this as an alternative to the talk page so it's more fast paced, just easier in general to communicate, and wouldn't fill up the talk page as much. https://discord.gg/wR2X5wXXgT Nussun05 (talk) 10:28, 18 January 2021 (UTC)

@Nussun05: It is frowned upon to form consensus off-wiki. If someone comes here and wants to know what the consensus is on this subject, they ought to be able to see it publicly here.--Jasper Deng (talk) 11:50, 18 January 2021 (UTC)

I might make a bot that can post what is said on the server to a talk page. Nussun05 (talk) 12:06, 18 January 2021 (UTC)

Might run afoul of copyright, and/or posting something that someone might not want said (I say quite a lot of things on IRC that shouldn't be reproduced here).

That being said, there's nothing wrong with chatting with folks on Discord (or IRC, or FB Messenger, or...) about on-wiki content (as mentioned, I do it all the time) but decisions requiring consensus should still primarily be done here. Primefac (talk) 14:53, 19 January 2021 (UTC)

I just feel discussing every single minor thing that could be wrong with the page could flood the talk page, just look how much there is already. Nussun05 (talk) 20:36, 19 January 2021 (UTC)

Technically a talk page is about discussing 'every single minor thing', since it is for the purpose of discussion. As long as the discussion is about improving the article in some way or an other, it can be posted here. A discord server could be used, but I think that most of the discussions should be conducted here for wider visibility.PNSMurthy (talk) 00:56, 24 January 2021 (UTC)

Massey et. al. 2020

I emailed Massey and I have the full tables from the new 2020 M 31 and M 33 paper now. Nussun05 (talk) 13:28, 24 January 2021 (UTC)

The following is a list of all the stars in the paper, we need to find out which stars are already in the list and to find the LGGS numbers for them: https://cdn.discordapp.com/attachments/738052748846563389/802901920347979816/Massey2020.csv. Faren29 (talk) 16:35, 24 January 2021 (UTC)

Sample of stars above 1,400 Rsol:

Name	Teff	logL	R☉
LGGS J004520.67+414717.3	4250	6.07	1999
LGGS J003919.11+404319.2	4150	5.88	1685
LGGS J004045.88+405037.2	4750	6.02	1511
LGGS J004248.37+412506.5	4750	6	1477 (Foreground object)
LGGS J004029.43+404610.0	4250	5.8	1465
LGGS J004038.49+403149.3	3900	5.35	1416

I'm always suspicious of intergalactic stars. How do we know these are accurate - since it is extremely hard to accurately predict the sizes of such distant objects. What method was used?PNSMurthy (talk) 03:25, 30 January 2021 (UTC)

I'd say the same about the star with 2535 solar radii. V255 Canis Majoris (talk) 18:56, 30 January 2021 (UTC)

New Largest Star

I'm definitely suspicious about the star from the Andromeda galaxy that tops this list. It size seems extreme (and most likely inaccurate). I don't think intergalactic stars with such inaccurate estimations should be included since they have large margins of error. It's extremely hard to predict the sizes of such distant objects, and most of their predicted sizes do not hold. I know I've raised this concern previously but I really think all intergalactic stars' sizes should be looked into.PNSMurthy (talk) 01:25, 31 January 2021 (UTC)

I tried to search for the star in SIMBAD, and apparently there is not much data regarding this object. There is not even data about its spectral type, temperature, or even the apparent magnitude. The only designation it has is the clumsy 2MASS Extended one, and its coordinates.

We need to be very suspicious about adding extragalactic stars in this list. Unless otherwise notable and well-cited (such as WOH G64), I would be quite hesitant to accept that they should be on this list, especially if they are just known in complicated catalogues. SkyFlubbler (talk) 06:08, 31 January 2021 (UTC)

Agreed. We shouldn't blindly add stars with extreme radii, but first see if other sources support the said star, and if the radii is in the realms of believability.PNSMurthy (talk) 03:43, 1 February 2021 (UTC)

VY CMa

I though VY CMa had a radius of 1400 Rsol, now why is it near 2000? (btw, on both this page and its own page)--WRMetacat108 (talk) 14:00, 17 November 2020 (UTC)

I found a newer source than that 1420 Rsol, which gives 2,069 Rsol Nussun05 (talk) — Preceding undated comment added 17:00, 17 November 2020 (UTC)

If Stephenson 2-18 were to be downscaled before any other star surpasses VY Canis Majoris or before it downsizes, VY Canis Majoris just may have the chance to be the largest star even just one last time. — Preceding unsigned comment added by V255 Canis Majoris (talk • contribs) 17:13, 23 November 2020 (UTC)

The only way this could be the case, is if another reference is found, which gives Stephenson 2-18 a lower radius, or if a new paper is published, which gives Stephenson 2-18 a smaller radius. For nostalgia purposes, seeing VY Canis Majoris back on top would certainly be pleasing to me. For now, however, 2,150 R_☉ is the only value given for Stephenson 2-18. Faren29 (talk) 21:05, 24 November 2020 (UTC)

I would love to see vycma as the largest star again. — Preceding unsigned comment added by 84.71.59.189 (talk) 08:58, 3 February 2021 (UTC)

V1804 Sagittarii

Could someone do some research on the star V1804 Sgr, a possible M9.1Iap supergiant star? I'd like to know if it's a RSG, and if it has a size estimate. Nussun05 (talk) 18:02, 23 September 2020 (UTC)

AGB star, probable Mira variable. Very little data on its properties. Spectral class given as M9.5 here with reference to a previous class of M9.5 Iap. No published parallax, distance unknown, hence luminosity and radius unknown. Lithopsian (talk) 19:55, 23 September 2020 (UTC)

This article: http://articles.adsabs.harvard.edu/full/2009ASPC..412..113W/0000113.000.html, states that it is an 'extreme supergiant'. That might be a start?PNSMurthy (talk) 01:55, 24 September 2020 (UTC)

Extremely cool. You're going to struggle to find enough material for an article, though. Lithopsian (talk) 08:53, 24 September 2020 (UTC)

True.PNSMurthy (talk) 10:49, 24 September 2020 (UTC)

So, with the release of Gaia EDR3 V1804 Sgr now has a parallax of 0.9465 mas, however, the astrometric noise values seem to be high. Nussun05 (talk) 17:34, 3 December 2020 (UTC)

Nothing has changed really. Still a very cool star, probably not all that far away, probably not particularly luminous, but what are you going to do with that information? There is no published luminosity, no published radius, and no valid way for us to calculate either for Wikipedia. The DR3 parallaxes themselves can probably be inserted to a number of articles, all interesting stuff, but until someone publishes papers based on it, probably not very relevant to this article. Lithopsian (talk) 21:57, 3 December 2020 (UTC)

Can't find that parallax anywhere, not even in Simbad or Google. Do you have a ref for that? 2A01:E0A:47A:F100:D96C:16C2:E87C:950D (talk) 12:16, 4 December 2020 (UTC)

VizieR entry. Lithopsian (talk) 15:04, 4 December 2020 (UTC)

Mohomous — Preceding unsigned comment added by 84.71.59.189 (talk) 09:34, 3 February 2021 (UTC)

Semi-protected edit request on 3 February 2021

Hey wikipedia, Vycma's size is uncertain but right now it's radius is about 2069 so it would be higher on the list. Also I just want vycma to be higher due to nostalgia. https://astronomical.fandom.com/wiki/VY_Canis_Majoris this website also states the fact that vycma's radius is 2069. 84.71.59.189 (talk) 08:52, 3 February 2021 (UTC)

 Not done for now: please establish a consensus for this alteration before using the {{edit semi-protected}} template. It looks like this issue has been discussed before on this talk page, and the best estimate we have for the radius is listed correctly in the article already; you can have a look at VY Canis Majoris as well if you'd like. If you still think there is an issue you can discuss it on the take page and try and establish a consensus for the change. Volteer1 (talk) 10:24, 3 February 2021 (UTC)

I think the size is mentioned on the list, but we're using a smaller estimate because its more reliable when compared to other stars and estimates.PNSMurthy (talk) 07:30, 4 February 2021 (UTC)

All stars from Ren et al 2020

Can someone add all the remaning stars from the Ren et. al. source? Thanks in advance. Nussun05 (talk) 20:57, 17 February 2021 (UTC)

Could you please link the paper here?PNSMurthy (talk) 07:16, 18 February 2021 (UTC)

https://arxiv.org/abs/2006.06605 here you go Nussun05 (talk) 07:58, 19 February 2021 (UTC)

Thanks!PNSMurthy (talk) 08:16, 19 February 2021 (UTC)

I have checked the paper and the table at the DOI link, and I do not recommend to add the stars to the list. We are not sure about the accuracy of the measurements simply because these are extragalactic stars that are too far away in order to obtain proper results (there is even one star listed at the table for the LMC with 13,127 R_⨀). Though most of the stars I see on the list are within the range of some well-established RSGs here in the galaxy, the existence of data like this one makes me skeptical about using this source at all. SkyFlubbler (talk) 08:45, 22 February 2021 (UTC)

Yeah, extragalactic stars in general are harder to measure because we don't know if they're a part of their apparent galaxy or not. Maybe we should just not include these sizes at all? Nussun05 (talk) 18:36, 22 February 2021 (UTC)

I would not recommend using this source at all, even for stars that may look like having acceptable sizes (most of the stars in the source are of ~700 solar radii). We should look carefully at the method on how they measured their diameters before putting them in this list. Most of these stars have their sizes measured using SBL via temperature-luminosity function, and while this method may be acceptable for stars within our galaxy (St2-18's size was actually derived using this method), I would not recommend it for extragalactic stars since it has proved to be having a lot of issues to be acceptably useful. I would rather pick up on the sizes of extragalactic stars if it was based on interferometry (say WOH G64, measured by the VLT) which is more reliable. Unless we find another source that measures the sizes of those stars via interferometry, I would not see any star on Ren et al's source to be included in the list of largest stars anytime soon. SkyFlubbler (talk) 07:32, 26 February 2021 (UTC)

Its not that all sources including extragalactic stars should be disregarded. Many papers publishing the sizes for the aforementioned stars are reliable and valid. Yet the sizes in this paper - now that I've looked at it, do seem a bit dubious. How on earth did they get 13,000 _⨀ for a star?PNSMurthy (talk) 22:20, 27 February 2021 (UTC)

It's not like I'm saying that all sources discussing about extragalactic stars should be thrown off. There are special cases where we could consider extragalactic stars based on what method is being used, and how they are verified by multiple sources. By the looks of the paper by Ren et al, I would be extremely skeptical about adding it. SkyFlubbler (talk) 04:36, 28 February 2021 (UTC)

I guess we should remove the stars already present from this source? Nussun05 (talk) 05:05, 28 February 2021 (UTC)

Delete Stephenson 2-18 from the list?

The source [2] for Stephenson 2-18 being 2,150 solar radii says on pp11-12 ‘Unfortunately, at this moment, the distance information is based on radial velocities (i.e., distances are estimated by assuming the flat rotation model of the Galaxy). Therefore, the distances could include a relatively large uncertainty (relative error of more than 50% according to the recent results of trigonometric parallax measurements; H. Imai 2012, private communication; theoretically, however, the distances to massive clusters may be improved in the future, because there are independent methodologies to measure the distances to clusters (see, e.g., Perryman et al. 1998; An et al. 2007)).’

This indicates that there is a high degree of uncertainty in the size of Stephenson 2-18, so would it not make sense to take it off the list until further, more accurate observations have been made?

SpaceImplorerExplorerImplorer (talk) 16:49, 14 March 2021 (UTC)

Almost every star on the list has some level or the other of uncertainty. It would be unfair to pick and crop this one alone. I think we should le forve it where it is until further evidence is uncovered for or against it.PNSMurthy (talk) 09:03, 15 March 2021 (UTC)

I have "finished" the list

I'm working on trying to complete and improve the general quality of the list here: https://en.wikipedia.org/wiki/User:Nussun05/Finishing_the_list_of_largest_stars. What do you all think and should it be replaced with this? Nussun05 (talk) 17:06, 16 April 2021 (UTC)

Hi, sorry for what I did to you last time but it looks great.--The Space Enthusiast (talk) 06:17, 19 April 2021 (UTC)

Looks great! There are some things from there that can be added here probably.PNSMurthy (talk) 08:48, 1 May 2021 (UTC)

Uncertainties again...

Several months ago, User:SpaceImplorerExplorerImplorer discussed about deleting Stephenson 2-18 from the list. User:PNSMurthy Came along and said that it would be unfair to remove it. Now, SpaceExplorerImplorerExplorer has added notes to Stephenson 2-18 and other stars with the same reference as that star. The uncertainty says that the distance to those stars are 50 % uncertain and this is actually stated in the paper, but for me that could be referring to other stars as the paper does not specify which star has the 50 % uncertainty in distance. I honestly don't entirely know what to do but I support PNSMurthy's decision. What are your opinions? Thank you. The Space Enthusiast (talk) 01:34, 6 June 2021 (UTC)

I personally think Stephenson 2-18 should go but for other reasons, like that it's brighter in the infrared than all of the other stars, thus giving a luminosity above the theoretical limit (logL = 5.5), another thing is that the temperature is way too cool for red supergiants. With these two factors I heavily doubt St 2-18 is that large, it's probably just a foreground AGB star or other less luminous star. Nussun05 (talk) 08:13, 6 June 2021 (UTC)

Okay I saw your removal of it in your sandbox... But I want to know other's opinions as well.The Space Enthusiast (talk) 08:30, 6 June 2021 (UTC)

The uncertainty refers to stars in RSGC1, RSGC2, RSGC2 SW (which incudes St2-18), Per OB1 and Mc8, and is due to the distances being based on radial velocities. The TESS Input Catalog (v8.0) gives a distance of ~3.9kpc, but this also has a high degree of uncertainty. It is also worth noting the 2010 article that gave a luminosity of 90,000 L⊙ based on a distance of 5.5kpc. This is a big difference to the luminosity (437,000 L⊙) reported in the 2012 article. SpaceImplorerExplorerImplorer (talk) 12:03, 6 June 2021 (UTC)

The 90,000 solar luminosity is based on Mid Infrared and Far infrared fluxes; it does not appear to include the near infrared, where most of Stephenson 2-18's energy is. Including that gives the luminosity by Fok and Humphreys et al. The Space Enthusiast (talk) 10:46, 6 June 2021 (UTC)

Oh, by the way, I have talking with Lithopsian and I said that there was a 50% uncertainty in St2-18's distance. He found the uncertainty in Fok.et al and said it was meaningless, because almost every other star in the list has uncertain distances (Especially those in Andromeda). What do you think of this?The Space Enthusiast (talk) 04:00, 7 June 2021 (UTC)

Is there then anything meaningful to say about the sizes of stars with a great uncertainty in their distance, especially those, such as Stephenson 2-18, that have a radius so much higher than what is predicted by theory? You could also argue then that most of the list is meaningless due to the fact that almost all stars have distances measured by radial velocities and that there would be a great uncertainty in the distance. SpaceImplorerExplorerImplorer (talk) 16:59 8 June 2021 (UTC)

The sizes are not meaningless, we should take note of things in the “Caveats” section. The Space Enthusiast (talk) 00:15, 9 June 2021 (UTC)

Yikes, indents would help. Anyway, the list is essentially meaningless and has been for a decade or more. The stars at the top of the list are statistically those with the most incorrect radius values. We have databases of thousands of (possible) red supergiants, identified by algorithm and classified by another algorithm, without much sanity checking. Objects such as foreground stars become classified as enormously luminous red supergiants. Out of true supergiants, of which the largest are of similar sizes within a modest range, the ones with the most inaccurate, for example, distance appear larger than the others and percolate to the top of the list. The star at the top of the list on any given day is almost certainly there because its radius is wildly inaccurate. Lithopsian (talk) 15:01, 10 June 2021 (UTC)

I've floated the idea of just nuking this article before, but no one seems to agree with me. This is odd, since the topic of "this is wildly inaccurate" and "list is essentially meaningless" keeps coming up. Primefac (talk) 15:33, 10 June 2021 (UTC) I've also re-threaded things for readability, especially since two of the usernames are very similar.

I don't think we should delete the page, but it needs a massive rework, and it needs to happen pretty soon. I would like you to try to help me on this, would be nice. Nussun05 (talk) 20:46, 10 June 2021 (UTC)

Should we use your version?The Space Enthusiast (talk) 23:11, 10 June 2021 (UTC)

What sort of rework? Keep in mind we just did a big overhaul of the list a year ago to clean it up and attempt to make it more accurate. Primefac (talk) 23:58, 10 June 2021 (UTC)

I really don't know. Maybe Nussun05's version? The Space Enthusiast (talk) 00:52, 11 June 2021 (UTC)

My version is slightly more accurate, but I still think it needs a huge rework Nussun05 (talk) 10:16, 11 June 2021 (UTC)

Okay, where are the more accurate parts?The Space Enthusiast (talk) 11:05, 11 June 2021 (UTC)

So... I just had a thought - why not include the uncertainties? Don't get me wrong, we can still have a table, but instead of giving them in any sort of "largest to smallest", put them alphabetically (or as it is, to keep the editing necessary low). Then, we can have a <timeline>-generated graphic showing their size with the uncertainties included (see H:ET and mw:Extension:EasyTimeline). This way we're not necessarily advocating for any particular size being "the best", can include references that support multiple sizes, and graphically show just how uncertain some of the calculated sizes can encompass. If we were to do this, I would definitely suggest breaking things up by galaxy, as we don't want the image to be too big. (Note also we don't need to use a timeline specifically, but the graphical software on MW is a little lacking, and I'm not sure an actual chart-with-uncertainties like {{Dot chart}} is really possible) Primefac (talk) 20:11, 11 June 2021 (UTC)

I really don’t get what kind of format you are talking about, but from your words, that is going to be an absolutely massive upheaval of the list !The Space Enthusiast (talk) 00:04, 12 June 2021 (UTC)

And "complete overhaul" doesn't give that indication? Primefac (talk) 02:38, 12 June 2021 (UTC)

”Complete overhaul” gives that indication, but it provided no context to what will the list look like. The term is vague, because it also does not provide context to what will change. The radii? The format? But your words provided a preview to how the reworked list looks like.The Space Enthusiast (talk) 03:55, 12 June 2021 (UTC)

I think it is necessary to include the uncertainties so that each star can be judged on its merits. Even though the caveats are there, it is not clear how they apply to specific stars, so there is a risk that the values in the list are seen to be accurate. I agree that a visualisation of the uncertainties would be useful. Also, changing the page title to List of possible largest stars could be a way of introducing some uncertainty from the beginning. SpaceImplorerExplorerImplorer (talk) 07:22 13 June 2021 (UTC)

The caveats apply to most stars in the list. I would like to see the List's new format! The Space Enthusiast (talk) 08:26, 13 June 2021 (UTC)

The caveats may apply to most of the stars, but this only applies in a general sense at the moment. Each star has a different degree of uncertainty in its radius. This should be made clear. SpaceImplorerExplorerImplorer (talk) 10:59 13 June 2021 (UTC)

I wouldn't disagree with including uncertainties, but we risk making the data appear more credible while actually being less reliable. The radii themselves are clearly comparable to eachother even if extremely uncertain and statistically prone to exaggeration due to the nature of always selecting the largest values from datasets, but any uncertainties that we include will not be in any way consistent or comparable. A good chunk of the values in the table are calculated by us from luminosity and temperature values (or in some cases angular diameters and distances), each of which may have their own uncertainties with no obvious way to weight them without falling foul of WP:OR. If we do have a published radius with a published uncertainty then it will almost always only be a partial uncertainty, for example based on the specific observations in that paper but ignoring for example uncertainties in the adopted distance or extinction. Lithopsian (talk) 13:53, 13 June 2021 (UTC)

Okay, but i would love to see the new list.Also,from your statement, are stars that have relatively uncertain distance but no published uncertainty in the physical parameters have only partial uncertainties? what should we do about these partial uncertainties?The Space Enthusiast (talk) 13:24, 13 June 2021 (UTC)

As a first step to this might I suggest replacing the list with my updated list? Nussun05 (talk) 21:43, 15 June 2021 (UTC)

At this point, this list is becoming too large to manoeuvre and many stars have wildly different estimates stemming from various scientific articles. Its also incredibly unfair to use just one size for each of these stars, since most have many other estimates. Its honestly pointless to try and correct all these stars. Why not just limit our search to well known stars with at least 3 accurate measurements (and state all these measurements in the article)?

Or, instead of stating the radii we derive ourselves from luminosity, etc, why dont we simply state the parameters in the article instead of stating only the size. We're essentially 'making' the sizes ourselves using derived information. I'd suggest stating the base information instead of the sizes.PNSMurthy (talk) 04:43, 22 June 2021 (UTC)

I think that we should do more research on methods used in a given paper and not just add any value they state, we have to consider the reliability of the values. It's not just the reliability of the methods though, we should also compare value to known limits, too see if they are reasonable. For example it is quite likely that 1,500 R_☉ is roughly the maximum possible radius a star can have. Even accurate stellar evolution models only produce radii up to about 1,400–1,500 R_☉. So it is clear that the parameters of stars with radii larger than that should be considered quite likely to be unreliable, or at least they should be taken with a grain of salt. I think what PNSMurthy said is probably a good idea, and I think we should maybe remake the list from scratch at this point considering how large and messy it is. Another suggestion is to have the page be split up into three lists, one for galactic stars, one for extragalactic stars, and finally the last for supernova progenitors. We could even make a list for intergalactic stars, not really necessary but would be interesting. Nussun05 (talk) 17:02, 2 July 2021 (UTC)

I also think that we should allow calculating radii from two different sources, it allows us to get the most accurate luminosity and most accurate temperature in one even if they are in separate papers. We should in that case put the values used to calculate it in the table and then put a note on the radius saying it was calculated from those values. Nussun05 (talk) 18:42, 4 July 2021 (UTC)

I still believe that if we are to have a true list of largest stars with sizes that have been stated in papers, we'll have to remove all of the stars which we have derived with our own calculations. In order to avoid this its best to simply state luminosity, temperature, etc. I know I've gone over this before but I think its the best method.PNSMurthy (talk) 03:27, 10 July 2021 (UTC)

The list will hopefully finally be complete

I am gonna get home tomorrow, then I can finally start fixing up this list once and for all. I will start with only galactic stars, and I'll like to get a good limit for the lowest size that will be included in it, 1,000 R_☉ is just too high. Nussun05 (talk) 18:24, 14 July 2021 (UTC)

Hello

Mad question to ask but it's for loads a Reasons The star LGGS J013418.56+303808.6

Could you just for a day put underneath it "Ania's star"

I will screen shot it then you can delete it, Guys to the daftest things for women but it's gotta be done.

Please help Sunnysi86 (talk) 18:15, 22 August 2021 (UTC)

In a word, no. Primefac (talk) 18:16, 22 August 2021 (UTC)

You could just edit and not publish it. Nussun05 (talk) 08:47, 26 August 2021 (UTC)

Semi-protected edit request on 27 September 2021

The list was trimmed though that means a lot of the latest information and sources have been cut off. Some of the stars are still stated to be larger than any on the trimmed list and the list ignores many updates. Some items are up to date but many of the other up to date items have been trimmed off.

The list was better before it was trimmed and was based on as much up to date information as possible. Ghkf (talk) 10:37, 27 September 2021 (UTC)

It really wasn't, a lot of stars were calculated from properties without really thinking about if the parameters are even reliable.

Declined. Although I agree with the sentiment, no specific edit request has been made. See WP:ER for details of how to submit an edit request. Lithopsian (talk) 10:53, 27 September 2021 (UTC)

How do you agree with that? Have you even seen the state of the list before it was reduced? Nussun05 (talk) 11:04, 27 September 2021 (UTC)

I really think we should start fact-checking the previous list version’s stars, including Stephenson 2-18. I would suggest starting from the most inaccurate ones from the previous list, but it is up for you to decide.-The Space Enthusiast (talk) 12:33, 27 September 2021 (UTC)

It's not really about fact-checking, obviously the radii present in the old list are stated in the paper, or at least the parameters to calculate a radius. Nussun05 (talk) 13:07, 27 September 2021 (UTC)

I cleaned the list

Hi, I have "reset" the list due to it being way too messy, I know it may seem controversial, but it is the right thing to do at this point. Nussun05 (talk) 16:23, 24 September 2021 (UTC)

Note [b] needs a rewrite or further explanation; it's not immediately obvious that "SBL" = Stefan–Boltzmann law, the {{expand list}} already gives the "will be expanded" disclaimer, what happens if/when we start using Gaia data, etc. I guess I'm not even sure I understand the point of the note. Primefac (talk) 15:35, 26 September 2021 (UTC)

Gaia distances are known to sometimes be unreliable, especially for red supergiants and other luminous stars, so I'm excluding them until a consensus has formed for what Gaia parallaxes are reliable for this use case. Nussun05 (talk) 16:40, 26 September 2021 (UTC)

Just no. I haven't followed all the changes here over the last few months, but the current table is based altogether too much on original research. Excluding all radius calculations based on the most common method of determining stellar parameters is not for you to decide. If you have a reliable source (more reliable than the hundreds of published papers using the method!) that says SFB is bogus for this situation, then you can think about doing this. Otherwise, you just have to quote what the physicists have decided is fit to be published. Likewise, there is nothing so fundamentally flawed about Gaia distance determinations that we should be censoring any source that uses them. Much pre-Gaia work is based on methods with their own flaws, and we will struggle to filter out what is OK and what is not. Luckily, we have a good method: if it is published in a peer-reviewed journal then we can use it. Of course, basing our own Wikipedia calculations on data such as a Gaia parallax and something published elsewhere such as an angular radius is WP:SYNTHESIS anyway, so no doubt some pruning is a good idea. Lithopsian (talk) 17:46, 26 September 2021 (UTC)

I'm not excluding them, I'm planning to add them later just to keep the list simple for now, since it will take research to decide all SBL radii to use. Nussun05 (talk) 18:43, 26 September 2021 (UTC)

It is okay for me. Has there been any news on ST2-18's Gaia DR3 parallax?The Space Enthusiast (talk) 23:31, 26 September 2021 (UTC)

Its Gaia parallax is still negative/too small in EDR3, which means it's unusable. Nussun05 (talk) 06:16, 27 September 2021 (UTC)

I've inserted a note into the list section mentioning the recent edits. Hopefully in the upcoming weeks/months we can add stars with reliable sources (I think that recently (namely over the last year) too many new stars were added that may or may not have been dubious. I feel cleaning the list was a good decision and now we can work to build it up again!

Okay.-The Space Enthusiast (talk) 09:28, 27 September 2021 (UTC)

Added the L/T_eff estimates, obviously something has to be done because several values (like V354 Cep), are outdated. Nussun05 (talk) 13:16, 27 September 2021 (UTC)

The only Gaia criteria we have atm is astrometric noise significance below or equal to 2, so that's what I'm gonna use for the time being. Nussun05 (talk) 13:17, 27 September 2021 (UTC)

Uncertanties in many things to discover

Well we know stars exist including large ones, though while we're uncertain about some and their sizes, we view their properties as uncertain, but in reality there are always new things to find out about and only time and technology will tell. There are likely to be more factors in stellar properties than what we already know or understand. New discoveries can change our understanding forever. We never really know what's out there. Just like how we thought Earth was the center of everything until later technology including the telescopes (like Galileo's for example) helped us realize we're not the center, but moving in a system and we learned our Solar System moves around our Milky Way which in turn moves across the universe and there's so much more in the universe than we ever observed or know. New discoveries can make us rethink things and even change theories and anything can break the boundaries of physics (like black holes for example). Plus for example, since the stellar model size limit is only theoretical, there's no guarantee the models are accurate and like I said, new discoveries can change the way we think and view stars and other stuff. Plus it's always good to keep things up as we're always on the updates with stuff like stars. Remember when we even found galaxies that are far larger than we once thought galaxies would get? — Preceding unsigned comment added by Ghkf (talk • contribs) 16:14, 27 September 2021 (UTC)

Not to be rude, but... what's your point? Primefac (talk) 16:37, 27 September 2021 (UTC)

This method isn't gonna work

While I do think it's best to use papers where radii are stated, certain stars would then have radii already known to be out of date (like V354 Cephei), but we wouldn't be able to change them. So my suggestion is that we are allowed to calculate radii as long as we are cautious about the values used to calculate it. Nussun05 (talk) 05:37, 28 September 2021 (UTC)

But what do we mean by cautious?-The Space Enthusiast (talk) 07:00, 28 September 2021 (UTC)

We should check if the values are reasonable given known limits, and also the accuracy of the method used to calculate luminosity/temperature or distance/angular diameter. Nussun05 (talk) 07:06, 28 September 2021 (UTC)

Where are WOH G64, RW Cephei, NML Cygni, EV Carinae, RSGC1-F01, HV 888, and Stephenson 2-18? Will they return? V255 Canis Majoris (talk) 07:55, 28 September 2021 (UTC)

WOH G64 and HV 888 is extragalactic, and the other's radii are not stated in the paper. Nussun05 (talk) 08:57, 28 September 2021 (UTC)

Be patient, because Nussun removed them because their radius was based on the Stefan-Boltzman law (I might have botched that, forgive me for my mispelling.)-The Space Enthusiast (talk) 07:59, 28 September 2021 (UTC)

Well, don't forget we have {{List of largest stars row}}. Primefac (talk) 10:40, 28 September 2021 (UTC)

I know we do, I'm working on listing some manually calculated radii in the pending additions page Talk:List_of_largest_known_stars/Pending_Additions Nussun05 (talk) 11:10, 28 September 2021 (UTC)

Semi-protected edit request on 29 September 2021

New Largest star 'Stephenson 2-18' with solar radii of 2150 to be added Alexxking (talk) 20:55, 29 September 2021 (UTC)

 Not done: please provide reliable sources that support the change you want to be made. ScottishFinnishRadish (talk) 20:58, 29 September 2021 (UTC)

 Not done: Just no, that size isn't reliable at all. Nussun05 (talk) 04:47, 30 September 2021 (UTC)

There isn't a largest star. The large stars on the list are almost entirely in our galaxy, including the famous VY Canis Majoris. We don't know the sizes of the stars in the countless other galaxies in our possibly infinite universe, and we would most likely not reach them, so we have no way to know their size. The largest stars also pulsate, because of events inside the star, as their cores run out of hydrogen and fuse helium instead. Their outer layers become ill-defined as well. This makes finding a largest star very hard, if not impossible. I hope you understood my point.-The Space Enthusiast (talk) 08:15, 30 September 2021 (UTC)

Exactly! That's why I suggest to rename the page to "List of largest known stars". Nussun05 (talk) 09:13, 30 September 2021 (UTC)

Add some pending additions

I think the manually calculated list is getting ready to be merged, however the Miras with radii stated should not be included yet. Nussun05 (talk) 05:15, 1 October 2021 (UTC)

The future of the list

Okay so, when extragalactic stars get added, I suggest we either make separate lists or make the rows have different colors based on galaxy. Nussun05 (talk) 07:51, 1 October 2021 (UTC)

No colours, per ACCESS issues. Based on previous versions of the page, I would not be opposed to different tables for different galaxies, or at the very least Andromeda, Triangulum, and the LMC (and a fourth for 'other'). Primefac (talk) 11:35, 1 October 2021 (UTC)

Don't forget about the Small Magellanic Cloud. Nussun05 (talk) 19:22, 1 October 2021 (UTC)

There were only 11 in the SMC, wasn't sure how small we wanted to make the individual tables. Primefac (talk) 19:33, 1 October 2021 (UTC)

Perhaps grouping both magellanic clouds would be sufficient? And also grouping M31 and M33, and all other galaxies as a separate category. Nussun05 (talk) 17:47, 2 October 2021 (UTC)

Title and consistency

If this list is no longer going to consider stars outside of our galaxy, then I would suggest renaming the article to "List of largest stars in the Milky Way" or something else along those lines.

I've noticed some consistency issues with the latest version. Several stars have been removed because their size estimates are heavily disputed, but the same is true for UY Scuti with some estimates putting it at less than 1000 solar radii. V354 Cephei and Mu Cephei are most likely under 1000 solar radii as well. All yellow hypergiants seem to have been removed despite some of them being estimated to be larger than some red supergiants. Even using conservative estimates, Rho Cassiopeiae and V382 Carinae (and possibly V509 Cassiopeiae) would easily make the list. There are a few other issues (the 2850 solar radii estimate for KY Cygni is extremely unlikely, same goes for the 1940 solar radii estimate for PZ Cassiopeiae, etc.). It doesn't make sense to me to include some dubious or disputed size estimates but not others and I'm really not sure why yellow hypergiants don't seem to be considered at all now.

I understand the list is being reworked so I just thought I'd give some feedback. --Carnifex33 (talk) 07:21, 30 September 2021 (UTC)

It's coming later, I didn't add any yellow hypergiants to prevent the list from becoming messy again. KY Cyg and PZ Cas' upper size estimates obviously aren't accurante, that's why they're in parentheses. Nussun05 (talk) 08:27, 30 September 2021 (UTC)

I agree that V354 Cephei is likely below 1,000 Rsol, it's just there's so far no way to add it without violating WP:OR or using less accurate luminosity estimates. Nussun05 (talk) 08:29, 30 September 2021 (UTC)

The list will probably get extragalactic stars later. Nussun05 (talk) 08:30, 30 September 2021 (UTC)

Why is V354 Cephei in 1520 solar radii when its radius in its article says 685 solar radii? The size doesn't seem convincing.

Ikr, it's way too big, I would use the 685 solar radii but it's based on a Gaia parallax with too much astrometric noise, even the page says so. Nussun05 (talk) 18:30, 30 September 2021 (UTC)

So what size do you plan to give it? And what about UY Scuti's size? V255 Canis Majoris (talk) 19:17, 30 September 2021 (UTC)

Not really sure yet, there aren't many sources that give a size to V354 Cep. The Mauron et. al. one sadly does not contain a temperature. UY Scuti's estimate might shrink in the future. Nussun05 (talk) 19:50, 30 September 2021 (UTC)

If the sizes of V354 Cephei and UY Scuti are not certain, is it really necessary for them to stay in the list for the time being since other stars like WOH G64, NML Cygni, RW Cephei, and the others have not returned yet? — Preceding unsigned comment added by V255 Canis Majoris (talk • contribs) 14:08, 3 October 2021 (UTC)

WOH G64 and NML Cygni can be found in the pending additions. RW Cephei currently does not have a known accurate radius estimate. Nussun05 (talk) 17:11, 3 October 2021 (UTC)

Help me add more stars

I am currently just adding random stars that come into my head, I would like it if someone could suggest any more stars (above 200 R_☉) that I could add. Nussun05 (talk) 14:40, 11 October 2021 (UTC)

What methods should be counted?

How should we define the method list? Obviously L/T_eff and AD make sense to include, but what about the rest of them? Nussun05 (talk) 10:40, 12 October 2021 (UTC)

Um... if they're used, they should be in the list? For example, ight now I know AM (atmospheric) isn't used, so it's kind of pointless to have it in the list; I was going to remove it just now but I figured if you were still doing big updates to the lists I wouldn't get in your way if there were values using it that would then cause it to be re-added. Primefac (talk) 10:42, 12 October 2021 (UTC)

AM was used for a star I had plans to add to the pending additions, but decided against it. Nussun05 (talk) 10:51, 12 October 2021 (UTC)

My big question is do we only use methods used for calculating radius itself, or methods for the values used in the L/T_eff and AD calculations? For the former case it seems like only L/T_eff, AD, and sometimes SED qualify. The stars that don't use those methods according to the list don't have it clearly stated in the paper(s) that the star uses L/T_eff or AD. Nussun05 (talk) 10:56, 12 October 2021 (UTC)

Hrm, interesting point. We want to say at a minimum (for example) that they used luminosity and temperature to calculate radius, but do we necessarily need to say (again for example) that they used Spectral line ratios in order to determine that temperature? My immediate thought is no, mainly because we will likely end up making things too complicated. I mean, do we really care how they got T or L? Primefac (talk) 11:26, 12 October 2021 (UTC)

I know, but it is hard when the paper doesn't state how they determined radius in any clear way. A solution to this problem is to assume a radius was calculated using L/T_eff if the paper doesn't mention anything about an angular diameter value, and if said value was used in the radius calculation. Nussun05 (talk) 11:38, 12 October 2021 (UTC)

If they are calculating the radius and don't give a method, then I would mark that as either "unknown" or "not given", but we should not be assuming any particular method was used. Primefac (talk) 11:44, 12 October 2021 (UTC)

Sure, maybe we can make them blank as I've already done for a few stars? Nussun05 (talk) 12:07, 12 October 2021 (UTC)

Uhhh...

Recently User:SpaceImplorerExplorer downgraded the extreme red hypergiant star VY Canis Majoris down to 605 solar radii. While he said that the 600 solar radii estimate was newer, it was published in the 2000's but the oft-quoted 1,420 solar radii estimate was published more recently, published around 2012 or 2013. I won't revert his edit just yet, because it might result in an edit war. What do all of you think?

P.S.: I believe the newer and larger estimate is more reliable. --The Space Enthusiast (talk) 23:50, 3 November 2021 (UTC)

I think it should remain as a range (605 — 1,420±120 R_☉) since it is hard to tell which estimate is more reliable. SpaceImplorerExplorerImplorer (talk) 12:13, 4 November 2021 (UTC)

The list was ruined once again

The point of resetting the list was to keep it clean and relatively undisputed. But now people are adding back unreliable estimates such as those from the TESS input catalog? What is going on? nussun (talk) 09:41, 29 November 2021 (UTC)

I really don't know...You might want to ask User:SpaceImplorerExplorerImplorer as he is the one adding the estimates (The list was edited only by him in the past week). — Preceding unsigned comment added by The Space Enthusiast (talk • contribs) 10:36, 29 November 2021 (UTC)

There's also the source that CD Hydri is from, where that star and all other stars have meaningless radius estimates, since the errors are bigger than the values themselves. nussun (talk) 11:00, 29 November 2021 (UTC)

Oh my.--The Space Enthusiast (talk) 11:04, 29 November 2021 (UTC)

I do not know what the uncertainty is in the TESS Input Catalogue although I do see with the one of CD Hydri. So I would change the name of the page to List of possible largest known stars to already note some uncertainty in the beginning. SpaceImplorerExplorerImplorer (talk) 15:10, 29 November 2021 (UTC)

Once, again VY Canis Majoris and Stephenson 2-18 have been added.--The Space Enthusiast (talk) 09:33, 30 November 2021 (UTC)

I've removed them, and I don't know why that person added it since it is unreliable.SpaceImplorerExplorerImplorer (talk) 09:59, 30 November 2021 (UTC)

Don't remove Vy Canis Majoris' estimate, because that is really reliable.--The Space Enthusiast (talk) 10:20, 30 November 2021 (UTC)

I didn't mean VY CMa's estimate I was only talking about St2-18 that was unreliable also adding that 1,420 ± 120Rsun estimate is just duplicating since it is already as a range from 605 – 1,420 ± 120Rsun. And both estimates are reliable as well.SpaceImplorerExplorerImplorer (talk) 10:43, 30 November 2021 (UTC)

Also in the paper that said ~605Rsun for VY CMa it said that it is certainly not in hydrostatic equilibrium so even if it is much different to the 1,420Rsun that is just because it is not spherical and it is also a variable star.SpaceImplorerExplorerImplorer (talk) 10:57, 30 November 2021 (UTC)

If UY Scuti's size is above the theoretical limit and isn't accurate, what is it still doing on top of the list? V255 Canis Majoris (talk) 23:12, 18 December 2021 (UTC)

It is not necasserily inaccurate and the lower scale radius is not so much larger than the theoretical limit although I would say it is probably between 1,000 R_☉ and 1,300 R_☉ and that it is hard to tell the radii of any red supergiant stars because their dust clouds can disturb observations so many of the stars on this list (above ~1,200 R_☉) are probably much smaller (eg. UY Sct, VY CMa (A?), AH Sco, S Per). SpaceImplorerExplorerImplorer (talk) 07:57, 19 December 2021 (UTC)

WP:OR and WP:SYNTHESIS. We shouldn't say it is larger than any theoretical limit without a specific reference to back up that claim and we certainly shouldn't be changing or omitting particular well-sourced values just because we have our own reasons for thinking they are invalid. There are good reasons for thinking this particular case is just plain wrong, but being larger than some extremely vague theoretical value is the least of them. Unfortunately until there is something in print that we can refer to as either a newer and better value or a reason to not use the old one, we 're stuck with it. Lithopsian (talk) 14:28, 19 December 2021 (UTC)

Inclusion criteria

I'm curious as to why this list now includes stars down to 200 solar radii. In the past, the limit was 700 or 1000 solar radii. SevenSpheresCelestia (talk) 19:15, 19 December 2021 (UTC)

I believe when the list was pruned it resulted in all reasonably-sourced values being re-added since we were no longer at a bazillion stars with 1000+ R_☉. I'm up for re-opening the discussion though. Primefac (talk) 13:20, 20 December 2021 (UTC)

Indeed, most of the loads of stars above 1,000 R_☉ were extragalactic stars with unreliable sources and with calculated radii, and for many other reasons. It is just not practical to have loads of unreliable references of stars, which made the list very messy. SpaceImplorerExplorerImplorer (talk) 10:05 21 December 2021 (UTC)

Is it practical to have loads of stars between 200-700 solar radii? SevenSpheresCelestia (talk) 20:20, 21 December 2021 (UTC)

In my opinion, no. Even in the "old days" (like, 2017) there were only about two dozen stars <700 R_☉ listed. We raised the floor to 1000 when the list got huge, but we don't need dozens of not-actually-all-that-large stars listed. Primefac (talk) 13:09, 22 December 2021 (UTC)

I feel that the stars used 'for comparison' exceed the stars this list is actually meant to catalogue. Surely we could remove some of the stars between 200 and 700 solar radii?PNSMurthy (talk) 05:22, 24 December 2021 (UTC)

All of them, no, but definitely most. I think if it is named (e.g. Pistol Star, Antares) or a part of a drawn constellation (e.g. σ CMa) it could be kept, because that to me fills the definition of "well-known" that we used in the past. It would leave us with about a dozen in that range. Primefac (talk) 12:14, 24 December 2021 (UTC)

I agree.--The Space Enthusiast (talk) 12:38, 24 December 2021 (UTC)

Should we prune the 'for comparison' part?PNSMurthy (talk) 13:20, 24 December 2021 (UTC)

I think it's useful to compare these gigantic stars to the bright ones we're used to seeing in the sky. Primefac (talk) 13:25, 24 December 2021 (UTC)