Talk:Herbig–Haro object

Italian version of this article could help

the Italian version looks as though it could be quite useful, has quite a few images and more inline citations Tom B (talk) 22:37, 27 December 2010 (UTC)

Needs more references

Hi all, the article currently needs more inline citations e.g. the 'Proper motions and variability' section doesn't have any Tom B (talk) 23:32, 24 October 2010 (UTC)

Stellar jet

For some reason, stellar jet redirects to this article. Why is this? I presume it's because there is some sort of connection between stellar jets and Herbig-Haro objects but it's not at all clear what this connection may be.

I came to this article looking for information on stellar jets, such as what are they? Where do they come from, what causes them? How big are they? What are they made of? Etc, etc. Perhaps they should have their own article. Nibios (talk) 16:03, 30 December 2010 (UTC)

I know that this is several years late, but I had a look and stellar jets seem to be called astrophysical jets on wikipedia, and they are similar to HH objects. NewbTopolis Rex (talk) 18:51, 26 November 2015 (UTC)

I hope there are no objections to Episodic Ejections

Ejected episodically by young stars like cannon salvos, the brightly glowing lobes travel through space at more than 700,000 kilometres per hour.

This is the most beautiful sentences I've ever read on wikipedia. But I changed it to "Episodically ejected by young stars like cannon salvos..." to make it ring even beautifulier.  :-)

But maybe you disagree. Maybe "ejected episodically" sounds more episodic? No, I think "episodically ejected" also sounds episodic. Tomato, tomato. Pigkeeper (talk) 17:24, 9 December 2015 (UTC)

Reference definitions

Hi

I would like to move the reference definitions form article body to reference section. This will reduce clutter in body and will make source reading easier for any future editing and improvement. If anybody has objection(s), please comment. Thanks--UbedJunejo (talk•cont) 13:54, 14 April 2018 (UTC)

Uncontroversial change. Lithopsian (talk) 12:51, 15 April 2018 (UTC)

Before copyediting....

@AhmadLX: are you satisfied all the content that you want to add is present? I recommend full copyediting is better afterwards, but am looking as I go...Cas Liber (talk · contribs) 00:52, 13 May 2018 (UTC)

• For instance, under Numbers maybe add some of the most prominent examples? Cas Liber (talk · contribs) 00:54, 13 May 2018 (UTC)

Hi Cas Liber, thank you for the ping. GOCE page says that waiting time is normally about a month. I do have a couple things to add to the article, but I think I will add them within 2-3 weeks at most. And yes, addition of famous HHOs in Numbers is also a great idea. Thank you :)--AhmadLX (talk) 13:07, 13 May 2018 (UTC)

GA Review

This review is transcluded from Talk:Herbig–Haro object/GA1. The edit link for this section can be used to add comments to the review.

Reviewer: Casliber (talk · contribs) 21:45, 18 May 2018 (UTC)

Ok I'll take a look. First up I will jot questions below and do some straightforward copyedits. Cas Liber (talk · contribs) 21:45, 18 May 2018 (UTC)

• I'd put something about their shape or dimensions in the lead. It is hard to get an idea of what the object is otherwise.

Done.--AhmadLX (talk) 22:37, 18 May 2018 (UTC)

"small" is a tricky word to use...I mean they are much bigger than solar systems for instance. Cas Liber (talk· contribs) 00:31, 19 May 2018 (UTC)

Removed.--AhmadLX (talk) 00:48, 19 May 2018 (UTC)

*Herbig and Haro met at an astronomy conference in Tucson, Arizona. - the date of this should be included

Date added--AhmadLX (talk) 22:37, 18 May 2018 (UTC)

link "accretion disk"

Done.--AhmadLX (talk) 00:48, 19 May 2018 (UTC)

• They can evolve visibly over quite short astronomical timescales... - this doesn't mean anything to the lay reader, and is ambiguous anyway ("short" again....), maybe put the specific time frame in (i.e. how quickly changes can be seen).

Done.

• In the Numbers and distribution, you should add notable examples - maybe nearest, easiest to see (brightest), largest/smallest, or just unusual examples.

Added two famous examples.

• The stars from which HH objects are emitted are all very young stars - this needs some sort of age estimate in years.

Done.

• Also explain how they are catalogued (HH...) and by whom.

There is no central body to catalog them, several people have compiled and published their catalogs with latest and largest being Reipurth, 2001 (link given in external links). As for naming convention, I had read some time ago that number in "HHn" represents the discovery number of the object; 1st one HH1, 50th HH50 etc. But I cannot find the source now. I will keep looking for the the source and add this info whenever I've found it.

Yeah, surely someone has talked about this somewhere...? Cas Liber (talk · contribs) 20:45, 21 May 2018 (UTC)

I read this in a journal publication or a review article some time ago. But I can't find the publication now :D

Done. Although I couldn't find the publication I was referring to, I found the earliest catalog of Herbig and it mentions the naming thing.AhmadLX (talk) 01:43, 25 May 2018 (UTC)

• we generally don't do galleries, so incorporating images into the text is preferable

Done. AhmadLX (talk) 18:03, 21 May 2018 (UTC)

• link or explain " class I binary star" and "class 1 protostar" - or rejig so this comes before the definition somehow (which is currently further along in the article)...

Linked.

• Also, Haro found these objects to be invisible in infrared...yet later on they are described as being visible in infrared. Also, surely the light indicates they are hot in some way?

This is because of two factors: 1) Back then they had less sensitive detectors, 2) They were photographing the emission patches, which lacked IR emission, as they didn't know back then if there was protostar or any mechanism of emission generation. Now we have better detectors and the section you are referring to (probably Source stars) says so about stars themselves. AhmadLX (talk) 22:14, 21 May 2018 (UTC)

NB: Earwigs copyvio clear. Cas Liber (talk · contribs) 14:10, 25 May 2018 (UTC)

1. Well written?:

Prose quality:

Manual of Style compliance:

2. Factually accurate and verifiable?:

References to sources:

Citations to reliable sources, where required:

No original research:

3. Broad in coverage?:

Major aspects:

Focused:

4. Reflects a neutral point of view?:

Fair representation without bias:

5. Reasonably stable?

No edit wars, etc. (Vandalism does not count against GA):

6. Illustrated by images, when possible and appropriate?:

Images are copyright tagged, and non-free images have fair use rationales:

Images are provided where possible and appropriate, with suitable captions:

Overall:

Pass or Fail: nice work. Cas Liber (talk · contribs) 14:10, 25 May 2018 (UTC)

ENGVAR

Why was this article changed from British English? --The Huhsz (talk) 10:32, 21 September 2019 (UTC)

I've changed it back per MOS:RETAIN. --The Huhsz (talk) 12:15, 21 September 2019 (UTC)

Huge speeds! Fantastic discovery!! Aliens here we come! Call the Express!!!

"... when narrow jets of partially ionised gas ejected by stars collide with nearby clouds of gas and dust at several hundred kilometres per second."

"Spectroscopic observations of HH objects' doppler shifts indicate velocities of several hundred kilometers per second, but ..."

"Spectroscopic observations of HH objects show they are moving away from the source stars at speeds of several hundred kilometres per second."

See Speed of light, which is "(approximately 300000 km/s ...)". In terms like those above that would be "three hundred kilometers per second". 'Three' is hardly 'several'.

Why does the text repeatedly make it sound like we've found faster-than-light travel?

Is this still a good article? Do any other astronomical articles exceed the speed of light also? Shenme (talk) 01:22, 22 September 2019 (UTC)

The speed of light is three hundred thousand kilometers per second. XOR'easter (talk) 02:11, 22 September 2019 (UTC)

Re:Three is hardly several, according to Oxford Several: More than two but not many. Headbomb {t · c · p · b} 02:20, 22 September 2019 (UTC)

Ah, me. Ate too well and then thought too little. Shenme (talk) 03:25, 22 September 2019 (UTC)