Talk:(455502) 2003 UZ413

Ugh ... OK

I've done a shedload of work on this updating the existing references and checking details against them, even though the record (except for certain webpages that stayed live for years, or to date) essentially stops dead at 2010.

Now that's finished, I've only now started looking for updated refs, and it's a right bit of spaghetti. There's probably further changes to be made to the record as far as the WP article stands, but I'm not sure exactly what yet.

First datapoint: a May 2019 paper (Mueller/Lellouch/Fornasier) which claims H=5.70±0.30 (!) and p=0.070+0.022
−0.015, for a resulting diameter (via some Beaming Parameter silliness, as otherwise it comes out at 367km) of 670+84.0
−82.0 km. Reference for that isn't their own work, but a 2014 paper by "Lacerda et al". Great.

There's a few other papers come up in a search of A&A but they don't seem to have anything interesting in them (or even particularly accurate; one, based on using Wavelets to better analyse the photometry of low-SNR TNOs, claims that the "TNOs are Cool" study reports a 1214km size for the object, something that I have been unable to find any kind of verification for - indeed TNOAC hardly seems to have any data for 2003 UZ413 in it at all, and certainly no diameter or even albedo estimates, only the same old 4.3 magnitude).

So, time to track down the Lacerda work, I guess? (Presumably: "TNOs Are Cool: A survey of the transneptunian region. XII. The albedo-color diversity of transneptunian objects."? Maybe that's one of the ones available via arXiv, but I have a feeling it isn't; the multipaper work is only about 50% represented on there. The one linking to it is "Trans-Neptunian objects and Centaurs at thermal wavelengths", [[1]]) ((Edit: looks like yet another incorrect cite - not only is "The albedo-color diversity..." (etc) not actually part XII of TNOAC - instead, it's unnumbered, and that number is taken by an entirely different work - but neither of them make even a single mention of UZ413. Dead end.)) — Preceding unsigned comment added by 146.199.60.87 (talk) 23:07, 19 August 2019 (UTC)

Update: another A&A one claims a very different colour profile - but still BB taxon - of V-R = 0.41±0.05 and V-I = 0.81±0.05, based on two of the already cited work, plus "Barucci et al 2011", whatever that is. So that's two to look up. (Oh hey; that one's actually a clickable link ... but, dammit, it's the Icarus journal - "New insights on ices in Centaur and Transneptunian populations", Volume 214, Issue 1, July 2011, Pages 297-307, FWIW - which is heavily paywalled and doesn't seem to be duplicated via any free-to-access source, unless you happen to have an OpenAthens account. Either way, not really convenient for wiki citing.) ((Guess I could just cite the work that links to it, as it has the data in? Thus, for future reference (heh), "Taxonomy of trans-Neptunian objects and Centaurs as seen from spectroscopy", F. Merlin, T. Hromakina, D. Perna, M. J. Hong and A. Alvarez-Candal, A&A 604, A86 (2017) DOI: 10.1051/0004-6361/201730933; [[2]]))

There's even a paper ([[3]]) predicting various occultation opportunities from 2012 thru 2014 (several per candidate object; nine in total for this one), but who knows if anything actually came of that?

FWIW, a random one seems to reprocess the original Perna 2010 paper and arrives at a more refined magnitude of H_V=4.361±0.068 - Absolute magnitudes and phase coefficients of trans-Neptunian objects, A. Alvarez-Candal et al, 2016; [[4]].

One last addition: Colours of Minor Bodies in the Outer Solar System, O.R. Hainaut, 2017, A&A; [[5]]; says H_R = 4.028±0.052, B-V = ?, V-R = 0.430±0.035 (variation being sigma, rather than whatever "d" is; both were given, latter is 0.008 instead), R-I = 0.387±0.068 (likewise, d = 0.015), plus some IR slopes which don't seem to get any love on WP so I'm not bothering with for the time being.

And that's about it. I dunno if this improves the data any, but it does make it potentially a lot messier. Question also is whether to use them to supercede the existing work, or to bolster it. But I'm tired, and hungry, and have other things to do now, and have totally lost my taste to carry on tonight. So if anyone coming across this spiel wants to pick up the baton, be my guest. 146.199.60.87 (talk) 23:00, 19 August 2019 (UTC)

Lacerda 2014 is this one. Ruslik_Zero 08:50, 20 August 2019 (UTC)

Thanks. That's one of the ones I already found though, and it contains no reference at all to 2003 UZ413. Maybe it gives instructions on how to convert other data into something useful, but it's many pages of dense scientific analysis that's far above my own ability to fully mentally parse, and the WP rules would likely class it as Original Research anyway. Maybe we can trust that the later paper which cited it has processed some other (??) data according to those instructions, but it's still obscure, and probably wouldn't pass verifiability guidelines. Plus the results matched to that cite are just wild compared to everything else - the magnitude is way off, and doesn't convert through albedo to anything close to the stated diameter. Plus another work that directly cites the same paper gives a size nearly twice as big, so something fishy is going on. 146.199.60.87 (talk) 14:26, 20 August 2019 (UTC)

Follow-up

Right, so... reviewing all the above with a fresher head (mind that I wrote the rest of this before seeing Ruslik's reply):

Mueller et al 2019 references Lacerda et al 2014, ie TNOs are Cool, for its unusual claim on the mag/albedo/diameter of the object, most likely incorrectly, so we can discount that.

The Wavelet paper is completely off the rails and seemingly incorrectly cited (or at least, these two reference papers that are in no way publicly accessible?), and so should also be discounted.

The only relevant things I could find in TNOAC seemed to be based on or directly quoting the already referenced works, and stating the same figures, so we can keep those instead of bothering to update.

TNOs and Centaurs at Thermal Wavelengths is actually the first paper mentioned above, i.e. it also hits the dumpster.

Taxonomy of TNOs and Centaurs via Spectroscopy is potentially useful, in its own right as it reproduces the data otherwise locked away in the paywalled work it cites, but it only updates the finer detail of the colour slopes.

None of occultations, or any other opportunities in the last five years, seem to have been taken advantage of, when I search around for them.

Alverez-Candal et al 2016 may also be worth citing for its more precise magnitude, though that still doesn't really help us with diameter as it says nothing about albedo (maybe the colour slopes would if we considered all the IR bands also measured and try fitting them to the examples given for other bodies in TNOAC and similar? Though that would firmly fall into the category of Original Research...)

Hainaut 2017 is an oddball that may also be worth mention as it finds a rather brighter magnitude (albeit R-band not V-band - though that shouldn't make much difference for something with such a flat spectrum in the visible bands?), and yet more different spectral slopes. The stats are given in a weird form, but the best I can find out trying to figure out what they mean is that d means "difference between paired data" (surely not applicable to the range on a slope figure, so it must mean something else, but the paper doesn't seem to make it clear what that is), and a refresher to my 20ish years stale statistics knowledge that lowercase-sigma stands for Standard Deviation (assuming the author hasn't reassigned that as well), and is therefore probably the most appropriate figure to state for the range around the given mean, even if it seems unusually large versus many of the others.

Again, I've got something else to go do right now, but that's essentially going to be my later course of action: ignoring the first papers found as they go into circular or otherwise invalid references for already dodgy looking data (maybe it's just typos not caught by editors, maybe it's something else, but I lack the knowledge to turn them into anything valid for inclusion), and adding in what little of Merlin et al 2017, Alverez-Candal et 2016 and Hainaut 2017 is actually relevant, plus proper cites for them of course. Maybe ditching some of the older data that, by then, is just clogging up the page, especially if it's got a much wider or entirely unstated range on the estimate. 146.199.60.87 (talk) 14:28, 20 August 2019 (UTC)

Yes, it would be good to get rid of data referenced only to web sites. Ruslik_Zero 20:27, 21 August 2019 (UTC)