Talk:(612911) 2004 XR190

Minor Planet Info

I've added the minor planet info box, but not all the info is there. My only sources were the press release and the list of Centaurs and SDOs. I'm no astronomer though, I'm guessing there are ways to get this stuff that I don't know. Jasongetsdown 03:41, 16 December 2005 (UTC)

Standard asteroid physical characteristics is a start...

Urhixidur 13:18, 16 December 2005 (UTC)

Also, when I e-mailed Lynne Allen to ask her about the images she mentioned the Buffy is actually an Extended Scattered Disk Object (ESDO) not an SDO. I've requested it. According to Lynne SDOs must have a perihelion less than 38 AU. Those that do not (Sedna and others) are ESDOs. I don't really have the experience in this area to write it myself. Jasongetsdown 15:55, 16 December 2005 (UTC)

We will have to figure out, what that means. My initial impression was "Extended" is a subcategory of all SDOs. It now seems I was wrong. Awolf002 16:45, 16 December 2005 (UTC)

This paper (by many of the same astronomers who found XR190) has some analysis of 2000 CR105. Apparently the key point is that they do not come close enough to Neptune to have been subject to the scattering effect that is the cause of other SDOs. This is noted in 2000 CR105. I would dig more but my lunch break ended a half hour ago :) Jasongetsdown 18:27, 16 December 2005 (UTC)

Exactly. This new object is particularly problematic because it has a fairly circular orbit and high inclination which speaks against scattering.--Jyril 18:34, 16 December 2005 (UTC)

Please, don't shorten the designation to "XR190", which is ambiguous and meaningless: it could be (71153) 1999 XR190, (111415) 2001 XR190, or a number of other objects besides this one. You can more or less expect one XR190 per year, these days...

Urhixidur 23:54, 16 December 2005 (UTC)

OK, then there's this one... how can the orbit be so circular? (see references) Dreg743 06:13, 7 June 2007 (UTC)

Extended scattered disk

I put a blurb section into Scattered disc about a possible Extended scattered disk. Just to "hedge our bets". Awolf002 20:25, 17 December 2005 (UTC)

Classification

Have a problem with my graphs. This object, in spite of its axis is classified as cubewano in the current MPCORB (col 162 – 165 = 0x10 for those who used this db). The distinction between cubewano and SDO seems to depend on the source. If I stick to the MPC classification some of our articles should be adopted. Recent Jewitt defines cubewano also as 39.4 < a <47.8. Not sure what to do; any suggestions are welcome. Thank you.. Eurocommuter 22:05, 14 February 2006 (UTC)

Name

Just putting this out there, but I heard 2004 XR190 may be named after the Roman goddess, Cardea. However, I have no reliable source to back this up.

Roman mythological vampire slayer? Cute. Of course, we have no way of knowing whether you, the discovery team, or someone else entirely coined that particular joke. :)

Incidentally, my understanding thus far is that the naming rules were underworld deities for Plutinos, creation deities for the other iceballs. Sedna was named outside this matrix, with Brown et. al. suggesting that arctic deities be used as the naming scheme for wholly-detached objects. Prior to Eris getting named, I think no SDO (Sedna excluded) had actually been named, and Eris isn't really a creation deity (at least inasmuch as pretty much all gods tend to date back to creation narratives, by definition), so I suppose SDOs could be in line for some other naming scheme entirely. The Tom 17:11, 21 May 2007 (UTC)

The name is fitting to go with the nickname, Buffy, but one can never tell what IAU will choose. When talking with Mike Brown about Eris before its name was official, he told me he did like the name Discordia. I wasn't surprised when the name Eris was chosen. Although, he also liked the name Kore. The one object that I really want to see receive an official name is 2005 FY9. However, I have heard nothing about what that name may be.

Speaking of which, do we really need to point out that "Buffy" is a fictional vampire slayer? Like what, compared to the "non-fictional" vampire-slayers? 79.194.32.128 (talk) 18:56, 31 May 2008 (UTC)

She could be a real vampire-slayer who is having trouble finding her quarry. --Aranae (talk) 04:06, 1 June 2008 (UTC)

Unfortunately, Kore is now also the name of a Jovian moon (Jupiter XLIX, formerly S/2003 J 14). Double sharp (talk) 15:25, 15 June 2014 (UTC)

Most tilted?

"With an inclination of 47 degrees, it is the most *tilted* object discovered thus far." Many objects have greater inclination that 47 degrees. Is that "most tilted dwarf planet candidate" perhaps? 76.116.43.72 (talk) 16:09, 30 June 2010 (UTC)

Both asteroid 1580 Betulia (i=52) and TNO 127546 (2002 XU93) (i=77/H=7.9) are easily more "tilted" than 2004 XR190 (i=46/H=4.5). (2006 HU122) has i=48/H=6.6, but with H=6.6 HU122 is likely at best only 318km (low albedo of 0.04 assumed) in diameter. Thank you for pointing out this errata. -- Kheider (talk) 18:41, 30 June 2010 (UTC)

2006 AO101

It says 2006 AO101 is 63.9 AU from the Sun. I think this is excessive. According to [1], 2006 AO101's aphelion is 63.9 AU from the Sun. Is 2006 AO101 really that far from the Sun?--Solomonfromfinland (talk) 06:23, 23 March 2013 (UTC)

JPL (and gives it a mean anomaly of 180.06 at epoch 2006-01-25[2]. Although this is not an angle, given the symmetry in Keplerian orbits, it does mean that it was just barely past aphelion at that time (and hence for some 7 years now). That means that the value looks OK. On the other hand, it is lost (error code E), so its orbit is insufficiently known to be able to pinpoint it again... --JorisvS (talk) 11:58, 23 March 2013 (UTC)

Highest inclination

I've tagged "With an inclination of 47 degrees, it is has the highest-inclination orbit of any possible dwarf planet discovered thus far" as dubious because there are 4 objects with H<7.5 that have higher inclinations. JPL Of these, 2005 NU125 and 2006 HU122 are listed by Brown as 'possible'. The other two are 2004 DG77 and 2012 DR30, which Brown list as 'probably not'. Brown's list

I'm unsure how to reasonably rephrase this, short of a complete rewrite. Suggestions? --JorisvS (talk) 21:13, 27 March 2014 (UTC)

It is certainly the largest of these highly inclined candidates: so, perhaps "With an inclination of 47 degrees, it is the largest dwarf planet candidate that has an inclination larger than 45 degrees..."? Double sharp (talk) 12:50, 10 June 2014 (UTC)

 Done Double sharp (talk) 14:13, 10 June 2014 (UTC)

Buffy

We need an admin to move this back to 2004 XR190 as Buffy is not an official name for this object. -- Kheider (talk) 19:40, 5 November 2017 (UTC)

CSD G6'd. Hopefully the admins take care of User:Knson soon.   ~ Tom.Reding (talk ⋅dgaf)  20:06, 5 November 2017 (UTC)

How do we convert apparent mag and distance into absolute mag for minor planets?

I had a look in the 2006 discovery paper to see if it claimed a magnitude for the object, which might be different from the other sources (Brown is also different, as is almost always the case, but I'm yet to edit that in), given that the diameter is somewhat different to the others. However, it only gives an apparent magnitude, plus distance, rather than absolute mag. I've looked up how to do the conversion and ended up getting nonsense results back, from my best effort and understanding of the formulae - generally in the H = ~12 range rather than ~4.5. Part of it may be down to not knowing the phase angle, but I don't entirely understand how you work that anyway - in any case, the need to use that to alter the magnitude by more than 7, and the figure in question being a log (and cosine?) of the angle means it would had to have been observed as a tiny sliver of a crescent to make any sense, which seems unlikely.

So given that H = m - (5 log10 (dBS x dBO / d0^2) - 2.5 log10 q(alpha)) isn't working, is there another way of doing it? Can you even do the calculation to a reasonable degree of precision if all you have is an apparent mag, a (rough: 59 +- 5 AU) helicentric distance, and an assumed geocentric distance (~58.5 AU) plus assumed (most likely narrow due to the great distance between Earth and 2004 RX190 reducing the potential parallax) phase angle? They must have done some processing behind the scenes, but it's not revealed in the paper, we just get an estimated diameter based on a range of albedos.

...dammit. I just realised I can probably reverse engineer it using the usual absmag + albedo to diameter formula(e), which generally work(s) just fine (except for Brown's figures, anyway). Which gives us about H=4.465 (!), the lowest precision figure which agrees with p=0.16 and d=425km, and p=0.04 and d=850km (though that may be a bit obvious seeing as a 4x increase in albedo means a halving of diameter)... though it could be they calculated the larger diameter first and rounded off to the nearest 10km, then did a simpler job of dividing down for the smaller, where 4.46 or 4.47 would work, but nothing further adrift, let alone 4.4 or 4.5. Strange.

Still, should there not be an end figure available to reverse engineer, my original question still stands... 146.199.60.87 (talk) 21:41, 18 August 2019 (UTC)

Use of "Buffy" throughout the article.

OK, it's a snappy and easily read nickname, but as it's not been officially designated as such, and pretty much all extant papers or lists of observations concerning the object after the initial discovery announcement reverted to "2004 XR₁₉₀", should we perhaps replace all instances of Buffy in the text - other than the actual paragraph noting the early use of the nickname and its origin - with the provisional designation, awaiting any proper (and most likely different) name it's eventually given?

Also, there's a nice pull quote from Allen in one of the linked New Scientist articles where she gives some suggestion that the name may have come from it being a potential "slayer of theories" because its orbital characteristics didn't fit well with the TNO origins / solar system evolution hypotheses of the time, would that be worth copying across into the relevant paragraph? 146.199.60.87 (talk) 00:44, 19 August 2019 (UTC)

Fresh information / research out there somewhere which hasn't been included in the article yet?

Just wondering, how would we even track such stuff down? The Johnston's Archive has a colour-taxon classification for the object, as well as a "colour" magnitude slope rating, which suggests there's more papers to be had out there beyond the now quite old Allen (2006) and Schaffer (2007; thus, 12 years now) ones already used and cited, but its own citing system is completely hopeless for attempting to follow up on... like there's no inline notes showing where each datum came from, just a huge pile of about thirty possible sources at the bottom of the page (maybe eight of them available online rather than as journals/papers you'd have to find at, or maybe request via, a university library), somehow relating to the preceding list of several hundred TNOs... Therefore, it's probably more productive to sidestep it entirely and go looking for updated information independently. But as any google searches for the provisional designation basically just points back to WP, or one of the endless (and inexplicable) sites that just blindly republishes Wiki pages, I don't feel confident about randomly running across it with a general websearch. Pointers are needed... 146.199.60.87 (talk) 00:55, 19 August 2019 (UTC)