Talk:Trans-Neptunian object

early discussion

Is "Kuiper Belt Object" the term in use rather than "Trans-Neptunian object"? See:

http://europe.cnn.com/2001/TECH/space/08/24/minor.planet/index.html

according to http://web.mit.edu/newsoffice/tt/2001/jul18/kuiper.html the newest object is in the Kuiper belt,(between 30 AU and 50 AU form our sun). The long peroid Comets are thought to originate further out (between 50 and 100 AU) in what has been called the Oort Cloud.

A term coming into favor with the Minor Planet Center is Distant Minor Planets. I'd suggest having that added into the hierarchy, as it includes both Centaurs and Kuiper Belt Objects, and BKBO's (beyond Kuiper Belt objects).... Trans-neptunian object is really a division that shouldn't be so "primary", as it would not include by definition any object with q<q_Neptune, Neptunian trojans, and the centaurs... where dynamically those and the Plutinos are rather tied to Neptune... Perhaps an article titled Distant minor planet would be a good addition?--Sturmde 15:32, 12 September 2005 (UTC)

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Current speculation in the astronomical community due to the gravitational disturbances of the planets suggest that there may be a larger planet...

How mainstream are these speculations? Last I heard, the perturbations of the outer planets were essentially accounted for, and the only speculated extra body was Nemesis, taken more seriously by biologists than by astronomers.

Main text has had the offending verbage removed See Planet X information. -- Mike Dill

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Added "most" to description of orbit beyond Neptune's, since plutinos like Pluto's orbits can be inside Neptune's.

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Do we really need to mention the controversy about Pluto being a planet? As far as I know, the IAU has said that for now, Pluto is a planet and that's that. shaggy 05:30, 18 December 2005 (UTC)

2003 EL61

I created an article for 2003 EL61. However, the official designation is 2003 EL₆₁. How can I edit the title of my article from 2003 EL61 to 2003 EL₆₁?

Use Unicode in the title. The subscripts are 0x2080 through 0x2089: « ₀ ₁ ₂ ₃ ₄ ₅ ₆ ₇ ₈ ₉ ».

Urhixidur 16:39, 2005 July 29 (UTC)

Charon, a TNO?

There's a little inconsistency in the definition of TNO and/or in the classification of Charon as one. I mean: if a TNO is an object that orbits the sun, then Charon isn't one, since it orbits Pluto.

Satellites of TNOs are also trans-Neptunian objects.--Jyril 11:00, 13 October 2005 (UTC)

Charon does orbit the sun, just as Pluto does. The fact that they also orbit each other does not change this.--Roentgenium111 (talk) 20:07, 10 March 2008 (UTC)

List of Notable TNOs

I added 2004 XR190 to the list. Large size, extreme inclination, and an unusally circular orbit for a SDO make it a very important discovery.

Let's not get caught up in the amount of controversy surrounding pluto's classification of "planet". Let's just acknowledge that there is controversy, and then send the reader somewhere with more signifigant information. shaggy 22:29, 26 February 2006 (UTC)

Fully agree. Let’s strive to have coherent and up to date entries on the subject, far from the cheap is Pluto a planet and which one is bigger headlines. With luck (and some albedos lower than the conservative assumptions) people (or computerised surveys) will find a dozen bodies bigger than Pluto in the next few years. Pluto could become like Vesta, the first (or even the only) name coming to mind of many people when asked about a category of bodies. Eurocommuter 18:22, 27 February 2006 (UTC)

First Scattered Disk Object

Browsing through the list [1] of SDOs at the minor planet center (like you do ...), it seems that a couple of them were discovered before (15874) 1996 TL66, which is given in a variety of articles as the first Scattered Disk Object. What a pain!

I think that good old TL66 was the first recognized SDO (there are a couple of papers on it, etc.), while the other ones were discovered earlier but only recognized as SDOs later on. In order of discovery they are (48639) 1995 TL8 (October 15, 1995), 1996 AS20, (26181) 1996 GQ21, and then (15784) 1996 TL66 (October 9, 1996). Not sure what to do about this... I will try to put TL8 in a few places as the "earliest discovered SDO" (a year earlier) along with TL66 as the "first SDO recognized".

By the way, another place where the above bodies appear as SDOs is [2] Deuar 20:30, 7 February 2006 (UTC)

Footers

The formatting on the footers is strange. There's an extra space that I can't seem to eliminate. I can't figure out if this is a problem with the templates or inside of this article. Is there a way to fix this? shaggy 18:29, 23 February 2006 (UTC)

You've got a real keen eye to spot that! Well, after a few false-starts, it appears to be fixed. Deuar 19:27, 23 February 2006 (UTC)

looks great! thanks! shaggy 23:35, 23 February 2006 (UTC)

The objects between Neptune and Pluto

I would appreciate your opinion on how to represent on my diagrams (TNO, Kuiper Belt, centaurs, cubewanos etc) the category of objects with a_Neptune < a < a_Pluto e.g. 2004 TY₃₆₄. The problem, originally spotted by User:Deuar, is that they do not fit easily into any of the categories without creating confusion.

• They are listed as centaurs by MPCORB but not as such by the current Circular and in contradiction with the IAU definition here. Showing them on the centaurs' diagram was misleading and I’ve fixed it (see Talk:Centaur_(planetoid). The original diagram can be found on my page(the thumb labeled Centaurs).
• The objects are trans-Neptunian by the same IAU definition.
• They are members of the Kuiper belt(?) (please quote refs)
• Some could be considered as classical (i.e. may have a long-term stable orbits outside major Neptune’s perturbations) but calling classical the ones closer to Neptune would be misleading IMHO
• Some of the objects e.g. 2004 TY₃₆₄ are on well-known orbits, so they are unlikely to be re-classified as plutinos in the future. Greying them out, for example, as unclassified would be misleading.
• The class seems to be somehow forgotten in all the major sources quoted in our articles. (I will greatly appreciate if someone provides me with other reference-level sources).

Thanks. Eurocommuter 11:00, 1 April 2006 (UTC)

Sizes/albedos in the table; NPOV

I’ve noticed that some entries in the table have been updated (e.g. Ixion) with Spitzer results cited abstract. Could someone indicate if this paper was published and where? I’m far from doubting Spitzer results in any way, of course, but in some cases they ‘halve’ the objects and appear at odds with (published) papers (including by some of the co-authors). Depending whether these data have been published (in a peer-reviewed journal), we need to modify the articles about specific objects. ‘Updating’ the values in the table here without mentioning these results in the articles could be confusing for an honest reader finding very different results in the articles. BTW, these results touch not only Ixion but also divide Varuna’s diameter by 2 and Varuna’s entry in the table remained untouched. Any information on the publication of these data greatly appreciated. Thank you Eurocommuter 14:38, 30 April 2006 (UTC)

I guess these values have not been published anywhere yet. Concerning Ixion, an albedo of 0.23 is mentioned in this preprint (page 2, Ixion section; source is private communication) which would indicate a diameter of ~620 km. Pre-Spitzer values of the list come probably from this preprint. Note it has some very crude values, like ≤ 1211 km for (84522) 2002 TC302 (H = 3.9) which makes them somewhat questionable. On the other hand, those values are probably from refereed sources.--Jyril 22:56, 30 April 2006 (UTC)

Thanks, Jyril. The same ‘private communication’ prompted my curiosity and this entry in the first place (it’s a small www!). We have even more confusing situation if you compare with the KBO list (e.g. Varuna there and here). Worse; some magnitudes (and/or albedos) could be visual some in red; as the result some entries ‘does not add up’ (on a log scale :). E.g. the entry for Charon seems to defy the formula. I believe we need to clean up and in some cases with substantial disparities (to be noted in the articles on the specific objects as well) to introduce double entries in the tables (e.g. 2003 UB313). Eurocommuter 09:40, 1 May 2006 (UTC)

The TNO diameters seem to have quite a lot of discrepancy. I wonder should we included different measurements on the table, or use only one measurement per object? The original list was sorted by size, which was very misleading since many of the diameters were obviously upper bounds only.--Jyril 05:46, 2 May 2006 (UTC)

Yes, the absolute magnitudes are the only ordering making sense I believe. If I find some time this week I’ll plot a diagram with the biggest objects (D/H space with constant albedo lines) and error bars or similar markers for major results. It could show separately different measurements in a few cases. With the backing of such a diagram, the table could unload the details and keep a single range, or - in a few publicized cases (e.g. 2003UB313) - multiple rows with different measures. See a poor draft. Eurocommuter 09:09, 2 May 2006 (UTC)

farthest known object

The page says: Currently lying at 97 AU away, the celestial body designated 2003 UB313 is the farthest known object in the solar system aren't Sedna and (87269) 2000 OO67 more distant?

• Sedna has a highly elliptical orbit, with its aphelion estimated at 975 AU and its perihelion at about 76.16 AU. --Pedro 12:54, 11 July 2006 (UTC)

Question is, where are these guys on their respective orbits now? Deuar 20:43, 11 July 2006 (UTC)

Sedna at 88.7AU, and 2000 OO67 at 20.8AU(!)Eurocommuter 21:27, 11 July 2006 (UTC)

I suppose technically, Voyager 1, which was 97.3 AU away last November is the "furthest known object in the solar system", though it's on a hyperbolic trajectory, which brings up the issue of what counts as "in the solar system." siafu 22:19, 11 July 2006 (UTC)

I have to say that is just inherently cool. As for the definition, i don't know... Deuar 22:29, 11 July 2006 (UTC)

maybe add the word natural somewhere in that sentence --71.134.254.219 02:30, 30 August 2006 (UTC)

Possible error?

2003 UB313's diameter is listed as 3000 ± 400. Is this correct? DanPMK 11:17, 24 July 2006 (UTC)

It is the value measured by IRAM based on infrared radiation which was the best we had before the Hubble measurements.--JyriL ^talk 17:05, 24 July 2006 (UTC)

I changed Eris to 2400 ± 100 per the Hubble measurements and the 2003 UB313 article. -- Kheider 23:09, 1 November 2006 (UTC)

Also, Orcus is listed here with a diameter of ~1500, but on its own Wikipedia and elsewhere I see ~946. HunterTruth (talk) 16:23, 26 January 2008 (UTC)

Merge: Ice dwarf

For discussion.

• Support. The article's content seems largely redundant with this article; no examples are given of "ice dwarfs" which are not TNOs. RandomCritic 04:03, 25 August 2006 (UTC)

I'm withdrawing the merge suggestion.RandomCritic 15:32, 25 August 2006 (UTC)

• Support TNO is redundant.
• Oppose the ice dwarf's content is unreferenced;
• Strongly oppose - ice dwarf is about dwarf planets, whereas the bulk of TNOs are much smaller objects. Deuar 12:44, 25 August 2006 (UTC)
• Oppose. Ice dwarf is a type of dwarf planet, so you can't just merge one type of dwarf planet and leave the others. Besides as Deuar said, most of the TNO's are smaller in size in comparison to ice dwarves. --Nishkid64 14:27, 25 August 2006 (UTC)
• Strong oppose. Ice dwarf is a physical classification and TNO is a dynamical one. Definite Venn diagram issues. The Tom 14:54, 25 August 2006 (UTC)
• Oppose. What really is an "ice dwarf"? Pluto and objects of its kind are sometimes called "ice dwarfs", but the term is not clearly defined. Make it a redirect into dwarf planet.--JyriL ^talk 17:01, 25 August 2006 (UTC)

Losing information on the various classes of KBOs

See Wikipedia:Articles for deletion/Twotino. Uncle G 07:52, 9 September 2006 (UTC)

Colour inconsistency

The text describing the grey and red types says all the largest TNOs except Sedna are grey. In the picture, Pluto looks red. -QuantumEngineer 21:20, 8 June 2007 (UTC)

Triton!

Should be mentioned as a former (?) TNO. Said: Rursus ☻ 07:20, 10 October 2007 (UTC)

... a probably former TNO ... Said: Rursus ☻ 07:20, 10 October 2007 (UTC)

merge section?

The "largest objects" section duplicates the "candidate objects" section of dwarf planet. Since the physical parameters of these bodies are so uncertain, and there are so many estimates floating around, I think we should merge to keep our account and references consistent. kwami (talk) 23:49, 26 January 2008 (UTC)

Trans-Neptunian versus trans-Neptune

The name of the article struck me as rather awkward, and I wondered how widespread it was. A simple Google search shows that trans-Neptune is about 2 to 4 times more popular.

Google search Totals

Trans-Neptunian region[3]	Trans-Neptune region[4]
040,100	159,000
Trans-Neptunian object[5]	Trans-Neptune object[6]
024,900	055,700

This suggests an inclusion of this variation in the article (which I've done), and a redirect for trans-Neptune object to this article (which I haven't). A quality assessment of the sites making use of the names is required to determine which should be listed first (?I didn't look at the IAU?), and possibly even a page-move to the more popular name. HarryAlffa (talk) 18:27, 2 June 2009 (UTC)

A layman's guess at what trans-Neptunian means might be, "beyond Neptune's belonging". Which is awkward - I think. HarryAlffa (talk) 20:36, 5 June 2009 (UTC)

Another search gives contrary results

Google search Totals

Trans-Neptunian region[7]	Trans-Neptune region[8]
0,040,000	1,430,000
Trans-Neptunian object[9]	Trans-Neptune object[10]
0,121,000	0,047,000

HarryAlffa (talk) 21:06, 5 June 2009 (UTC)

Your Google links don't work for me (and it looks like you were doing the wrong searches anyway). I get about 16,400 hits for Trans-Neptunian object, and about 355 hits for Trans-Neptune object. --Zundark (talk) 08:48, 6 June 2009 (UTC)

Harry if I am reading your google search right, you told Google to search for all occurrences of Trans-Neptunian but to exclude results with the word "Neptune". I don't think excluding the subject from the search makes any sense. -- Kheider (talk) 13:18, 6 June 2009 (UTC)

If I seach sg & pl and exclude "Trans-Neptunian object(s)", I get 2 Gghits.[11] The opposite gets maybe 4100 Gghits.[12] At GoogleBooks, there is 1 hit, which uses the phrase only twice. The opposite gets 44 hits, including titles by popular authors like Neil deGrasse Tyson. kwami (talk) 15:21, 6 June 2009 (UTC)

I tried to do too much, the first search was; trans-Neptune -Neptunian. Which would give pages which exclusively use "trans-Neptune", a useful search & result. I then fooled myself by switching this around to; trans-Neptunian -Neptune, with variation on object and region. So;

• Exclusive trans-Neptunian use, Google search terms;trans-Neptunian -"trans-Neptune": 76,300
• Exclusive trans-Neptune use, Google search terms;trans-Neptune -"trans-Neptunian": 113,000

Google can't be relied on for repeatability of number of results. The same search will give different numbers if there is/isn't a negative search term - even when the -ve term is random letters. Useful as very rough indicator only. HarryAlffa (talk) 21:38, 8 June 2009 (UTC)

You forgot the quotation marks, so you also got hits for "Neptune". With the quotes, I get 2 k-hits for Neptune & 61 k-hits for Neptunian. kwami (talk) 21:49, 8 June 2009 (UTC)

Like this? HarryAlffa (talk) 19:03, 22 July 2009 (UTC)

• Exclusive trans-Neptunian use, Google search terms; "trans-Neptunian" -"trans-Neptune": 57,600
• Exclusive trans-Neptune use, Google search terms; "trans-Neptune" -"trans-Neptunian": 1,820

I think this is enough to say both terms are used. HarryAlffa (talk) 19:03, 22 July 2009 (UTC)

"Trans-Neptune, the Drag Queen Cosmonaut"—that's the top hit. Then there's "The resonance between astrology and astronomy; Searching for Trans-Neptune reveals evidence of Transpluto". We need to search for "trans-Neptune object." There are instances of this, but [13] gets only 52 ghits (it says 310, but when you omit repeated results, it's 52, as you'll see if you click on the last page), whereas the other way 'round[14] gets 16,300 ghits. That's a pretty sig. ratio. kwami (talk) 23:41, 22 July 2009 (UTC)

From my last edit summary, "Significance is not measured comparatively". I'm amazed at the number of Wikipedians in the science articles apparently unable to grasp simple logic. Can no one see that it is a fallacy to use a ratio measurement when deciding if the usage of a term is significant or not to be used in an article? HarryAlffa (talk) 15:53, 2 August 2009 (UTC)