Template talk:Dwarf planets

This template does not require a rating on Wikipedia's content assessment scale. It is of interest to the following WikiProjects:

Astronomy: Astronomical objects / Solar System This template is within the scope of WikiProject Astronomy, which collaborates on articles related to Astronomy on Wikipedia.AstronomyWikipedia:WikiProject AstronomyTemplate:WikiProject AstronomyAstronomy This template is supported by WikiProject Astronomical objects, which collaborates on articles related to astronomical objects. This template is supported by Solar System task force.

Including Sedna in the Oort cloud is speculation and should not be enshrined as accepted classification. kwami 02:40, 2005 August 2 (UTC)

Removed the mention of Oort cloud (again). This template is used with {{MinorPlanets_Footer}}, so even the link is not needed.--Jyril 23:22, August 3, 2005 (UTC)

Since when is Triton trans-Neptunian? Ken Arromdee 15:46, 23 September 2005 (UTC)[reply]

Not since it was captured. Removed. --Jyril 16:25, 23 September 2005 (UTC)[reply]

I created an article for (55637) 2002 UX25, it's just a stub for now. I couldn't find any more information, but it has the orbital elements. shaggy 01:22, 20 December 2005 (UTC)[reply]

Not to be overposessive of a template I created or anything, but I think a simple KB/SD bifurcation makes more sense in the template. For one, we don't have to mix multiple levels of taxon—spatial-region-a and spatial-region-b is a simple divide, while spatial-region-a-objects, spatial-region-b-objects-with-orbital-characteristics-x and spatial-region-b-objects-with-orbital-characteristics-y is needlessly muddled. Secondly, the KB/SD split preserves the convention of going innermost to outermost, as no KBO is closer to the sun than any SDO (short-term orbital overlaps aside), while cubewanos and plutinos have a hopelessly intermingled neighborhood with no one set clearly closer or farther from the sun (plutinos are, on average, closer, for what it's worth). Finally, there are no shortage of orbital-characteristic-based categorizations that could be applied, despite the fact the template gives the impression there are only three. SDOs, for instance, can be subdivided between those in resonant and non-resonant orbits (2003 UB₃₁₃ being in 17:5 or something bizarre like that), while KBOs have been found in all manner of odd resonances other than just 3:2 (plutino) and nonresonant (cubewano). -The Tom 15:54, 2 October 2005 (UTC)[reply]

There's an interesting alternate list here. By their estimation 2002 UX25 should be off and 1996 TL66 and Huya should be on. --Patteroast 23:57, 9 July 2007 (UTC)[reply]

I added the non-haumeids from Tancredi's list. The haumeids (known or probable) on his list are (55636) 2002 TX₃₀₀, 2005 RR₄₃, and 2002 OP₃₂: these are probably a lot smaller than the values he uses. (He gives 2002 TX₃₀₀ as having a diameter of 800 km, when more recent occultation data gives one of only 286 km.) Double sharp (talk) 13:54, 1 June 2014 (UTC)[reply]

I want to move this template to "Template:Plutoids" because it is more concise. In addition, I do not understand why User:Ckatz revert my move... UU (talk) 08:53, 13 May 2009 (UTC)[reply]

Combined the two KB sections and the two SD sections. Also changed the wording "candidates" to "likely": they either are DPs or they are not. They are not candidates that will become DPs if recognized. — kwami (talk) 20:44, 23 December 2012 (UTC)[reply]

As Ruslik0 said in his edit summary, "no reason to single out these three bodies". (Though there is consensus that the IAU five should be separated to some extent.) — kwami (talk) 22:15, 25 December 2012 (UTC)[reply]

Okay, I think that's acceptable. It's weird to call them "candidates", since it's not like they become DPs after being evaluated, but that's the wording we use in other articles, so if we change it we should change it everywhere. — kwami (talk) 19:58, 26 December 2012 (UTC)[reply]

We now have Vesta as a possible former DP. Actually, it's quite clear that it once as a DP, so I don't think we need the question mark. That would be better suited to Psyche and Eunomia, both of which show evidence of differentiation. If we're going to add Vesta, shouldn't we add all known or suspected former DPs in the asteroid belt? What about Phoebe? Triton? — kwami (talk) 20:43, 9 March 2015 (UTC)[reply]

Triton was once a DP, but no longer because it was captured by Neptune, but has remained physically intact. Phoebe is different because it was both captured and disrupted. I'm not against including these, but it makes sense to think about how to best do this, keeping this template reasonably compact. --JorisvS (talk) 09:17, 10 March 2015 (UTC)[reply]

What about this: --JorisvS (talk) 17:44, 10 March 2015 (UTC)[reply]

According to Pallas' article, it has only been a candidate. Vesta's article has this: "Vesta's shape is close to a gravitationally relaxed oblate spheroid,[58] but the large concavity and protrusion at the southern pole (see 'Surface features' below) combined with a mass less than 5×1020 kg precluded Vesta from automatically being considered a dwarf planet under International Astronomical Union (IAU) Resolution XXVI 5". They are both given category "Former dwarf planet candidates", Vesta also "Former dwarf planets". 46.132.92.59 (talk) 12:32, 26 May 2025 (UTC)[reply]

Gotta go, but I don't think "disrupted out of equilibrium" is right. They froze out of equilibrium and because of that couldn't recover from subsequent battering.

Also, the list (not your version) is getting ridiculous. The list of "possible" DPs (as in anything that could possibly be 200 km in diameter) would be pages long. — kwami (talk) 23:54, 28 August 2015 (UTC)[reply]

The revision was changed just to make it more streamlined. The overall content is mostly the same, but the Kuiper belt category was split into the cubewanos, twotinos, plutinos, and other resonant objects. I decided to keep the possible asteroids to four: Pallas, Hygiea, Eunomia, and Psyche.

All either have an ellipsoidal shape (Pallas, Eunomia, Psyche) or an unknown shape (Hygiea) and are also above 200km. They are the only ones that meet both criteria, hence why I seeked to include them. Changing it to "frozen out of equilibrium" would be a good change. DN-boards1 (talk) 00:03, 29 August 2015 (UTC)[reply]

No, they're not ellipsoidal. And the 200km only applies to icy bodies, and even then it's optimistic, given that Proteus is over 400km and not round. No-one thinks that a chunk of iron 300km across (Psyche) is in HE.

Eunomia is the largest fragment of an asteroid that may be a former DP. Maybe Eunomia family could go in the 'former' category. And Psyche is presumably the core of a former DP. But I'd like to see a ref.

Pallas and Hygiea are out-of-round. No-one but you is proposing that they might be DPs. Get published in a RS and we can cite you, otherwise this is unsupported OR. — kwami (talk) 01:49, 29 August 2015 (UTC)[reply]

I found lightcurve models of Cybele:

http://astro.troja.mff.cuni.cz/projects/asteroids3D/data/archive/1-1000/A483.M783.shape.png

Not QUITE round, possibly a former DP?

But Pallas....

http://astro.troja.mff.cuni.cz/projects/asteroids3D/data/archive/1-1000/A101.M101.shape.png

http://astro.troja.mff.cuni.cz/projects/asteroids3D/data/archive/1-1000/A101.M102.shape.png

I uhh...see a slightly irregular sphere. A prolate spheroid. The lightcurve models seem to show HE in Pallas but not Cybele, Hygiea, Psyche, etc. Pallas is quite clearly close to or in HE. We had some data, i.e. the HST images, that left some questions, but now we have lightcurve data. This obviously looks round. In fact, thus far, it's the ONLY one besides Ceres to do this, to be almost perfectly round. I mean seriously, look at the images. Am I the only one who sees an object in HE here? DN-boards1 (talk) 21:42, 2 October 2015 (UTC)[reply]

Yes, you are only the one to see an object in HE here. Double sharp (talk) 05:44, 3 October 2015 (UTC)[reply]

I'm concerned about the development of some of these lists, like that represented by this template on dwarf planets. Wikipedia is supposed to rely on sources. It is not supposed to rely on original research. Yes, it might sometimes seem clear to an individual editor that this or that small chuck of stuff is or is not a dwarf planet, or, similarly, whether it is or is not in hydrostatic equilibrium. But in other cases it really is not clear and it is not for us to try to label things without a source. I perceive that there is some inference going on in the case of this template on dwarf planets. In particular, we have listed as "see also" Charon, Vanth, Dysnomia, and Hi'iaka. Other objects are listed as well. Why? Are these recognized as "dwarf planets" as per some cited source? Yes or no? Is this just some vague association that is being suggested because these are objects that happen to orbit officially designated dwarf planets? The uninitiated reader of the template is not given a clue. What about the objects put into the various categories in this template? Are each of these reliably sourced? More generally, we should not feel compelled to fill out lists of objects, putting this or that object into one or more of several different categories. Lists don't need to be complete. Reporting that an object belongs in a certain category should not rely on our own original research. It should only rely on a cited source. Isambard Kingdom (talk) 06:40, 19 September 2015 (UTC)[reply]

The categorization. About that.

-The organization into plutinos, etc. is for convenience. The Kuiper belt section was getting overly long and crowded, so it was divided into more accurate categories, per the DES. -Charon, Vanth, Dysnomia, and Hi'iaka have sometimes been called "binary dwarf planets" as A) They are in hydrostatic equilibrium B) They are of a large size compared to their parent body - the ratio is actually quite amazing, considering the size. They each cause a noticeable effect on their parent dwarf planet (I'll consider Orcus to be a DP for convenience here), in the case of Charon and Vanth causing them and their parent body to revolve around a barycenter outside either body, and in the case of Dysnomia and Hi'iaka being prominent and causing them and their parent bodies to be tidally locked to one another.

Basically, those four, if the IAU allowed binary dwarf planets, WOULD be considered DPs. --DN-boards1 (talk) 05:16, 20 September 2015 (UTC)[reply]

Hello? My question is about sources (books, published papers written by authorities). We need to cite them. Isambard Kingdom (talk) 06:24, 20 September 2015 (UTC)[reply]

I don't have a list of sources for binary DPs on me, but quite a lot of people refer to Charon as a binary dwarf planet. I'll get back to you on the other three. --DN-boards1 (talk) 06:35, 20 September 2015 (UTC)[reply]

Sir/Madam, you really don't seem to understand. I'm saying that we need a cited source for every single object in the template. Isambard Kingdom (talk) 06:45, 20 September 2015 (UTC)[reply]

Just to clear things up, I'm a female. --DN-boards1 (talk) 07:19, 20 September 2015 (UTC)[reply]

Either way, I am concerned. Isambard Kingdom (talk) 07:35, 20 September 2015 (UTC)[reply]

Dysnomia's size is not known very well. At the bottom end it may be only 100 km in diameter, which is surely not enough for HE. At the upper end it may be 734 km in diameter! So we should be very careful about that one. Hi'iaka is at ≈320 km, which is only "maybe". Vanth seems to be more sure than either of these, with the colour suggesting albedo 0.12 that would give 378(100) km.

As for Charon, the double-planet thing seems to be common, but alas, not an idea picked up by all that many RS's. Here's NASA (and that was the only RS I found up there in the Google hits...) Even the old IAU 12-planet resolution, which would have called Charon a planet, doesn't seem to mention "double planet". (Though maybe we might have better luck searching Alan Stern's writings?) Double sharp (talk) 04:03, 21 September 2015 (UTC)[reply]

P.S. Tidal locking is not really known for any of them save the Pluto—Charon and Orcus—Vanth systems. Double sharp (talk) 04:05, 21 September 2015 (UTC)[reply]

Just noting that the black and white photo of Ceres should be replaced with the colour version released in October. 134340Goat (talk) 04:14, 4 March 2016 (UTC)[reply]

 Done. --JorisvS (talk) 11:23, 4 March 2016 (UTC)[reply]

Because of an absolute magnitude of 4.1, i think we should add 2020 MK53 here. 181.115.171.211 (talk) 01:59, 7 February 2025 (UTC)[reply]

Negative. No indication that it meets any criteria. Renerpho (talk) 03:32, 8 February 2025 (UTC)[reply]

(666823) 2010 VR₁₁ is a cubewano that Mike Brown says is possibly a dwarf planet. (even still it’s about 350 km) so should it be added?

source: (666823) 2010 VR11 Fred1000000000 (talk) 11:32, 3 July 2025 (UTC)[reply]

No, we restrict this list based on diameter/absolute magnitude criteria as stated on the template. Brown's list for possible dwarf planets is now known to be overly optimistic, and objects smaller than Orcus or Salacia show increasingly little signs of ever having had planetary-type geological activity or hydrostatic equilibrium. ArkHyena (they/any) 14:13, 3 July 2025 (UTC)[reply]

It's not a dwarf planet, and I agree with ArkHyena above. Plus, (666823) 2010 VR11 is going to be deleted anyways, so... Wikipedia:Articles for deletion/(666823) 2010 VR11 Nrco0e (talk • contribs) 21:53, 3 July 2025 (UTC)[reply]

Okay Fred1000000000 (talk) 23:44, 3 July 2025 (UTC)[reply]

(612911) 2004 XR₁₉₀ (Buffy) is a SDO which could be (at most) 850 km so should it be added?

source:(612911) 2004 XR190 Fred1000000000 (talk) 23:43, 3 July 2025 (UTC)[reply]

No. 2004 XR190 has an absolute magnitude (H) of 4.34 (from JPL), which is greater than 4.2. The dwarf planets template only includes objects with absolute magnitude less than 4.2. Nrco0e (talk • contribs) 18:05, 4 July 2025 (UTC)[reply]

i think if the only source for the diameter being possibly greater than 700 km is a calculation based on albedo, and the albedo is greater than 4.2, then it should be excluded even if it is notable for other reasons.

i just removed 2 objects from the template based on this reasoning, and added 1 that was requested above because we do list its albedo as being less than 4.2. we can of course adjust those limits; there's nothing special about them, but it's a balancing act between including notable and likely objects and excluding non-notable and unlikely ones. — kwami (talk) 19:36, 4 July 2025 (UTC)[reply]

Okay Fred1000000000 (talk) 22:27, 4 July 2025 (UTC)[reply]

2020 MK53 is a SDO which is 500-600 km, which is to small to be on the list but it does have a Apparent magnitude of 25.6 so should be deleted? Fred1000000000 (talk) 22:31, 4 July 2025 (UTC)[reply]

we don't have a measured size, only an albedo, and the albedo is below our cutoff. we can of course change the cutoff from 4.2, but we should be consistent. — kwami (talk) 06:12, 5 July 2025 (UTC)[reply]

(55636) 2002 TX₃₀₀ is a cubewano which is on the IAU draft although 286 ± 10 so should be added?

source:(55636) 2002 TX300 Fred1000000000 (talk) 20:25, 5 July 2025 (UTC)[reply]

Oh wait I just noticed it could be 891.6 km oops Fred1000000000 (talk) 20:27, 5 July 2025 (UTC)[reply]

20000 Varuna is a cubewano that could be 822 km so should it be added? Fred1000000000 (talk) 20:18, 6 July 2025 (UTC)[reply]

yes, done — kwami (talk) 02:25, 8 July 2025 (UTC)[reply]

Thank you Fred1000000000 (talk) 17:26, 8 July 2025 (UTC)[reply]

(145451) 2005 RM₄₃ is a TNO that is ≈644 km so should be added?

(145451) 2005 RM43 Fred1000000000 (talk) 19:06, 22 July 2025 (UTC)[reply]

if the diameter + 1 sigma is at least 700, then yes, but i can't find an error bar — kwami (talk) 10:13, 2 September 2025 (UTC)[reply]

Since 2020 MK₅₃ and 2021 LL₃₇'s pages were removed due to failing the notability criteria, should they be removed from the Dwarf Planets template? Thirtyfourninety (talk) 16:04, 26 August 2025 (UTC)[reply]

i'd say no. whether they meet our inclusion criteria here is unrelated to whether they meet our notability criteria. we should include all objects that meet our criteria. if there are too many, we can make the criteria more strict. — kwami (talk) 10:11, 2 September 2025 (UTC)[reply]

Okay, I understand that. Thirtyfourninety (talk) 14:02, 2 September 2025 (UTC)[reply]

now that it's named, do you think we should add rumina per the previous thread? i don't know whether one sigma would bring it over 700 km or not. — kwami (talk) 18:24, 2 September 2025 (UTC)[reply]

I'm not quite sure either. Thirtyfourninety (talk) 20:30, 2 September 2025 (UTC)[reply]

i added Gǃkúnǁʼhòmdímà and Uni because they meet the magnitude criterion, even though Grundy has determined that Gǃkúnǁʼhòmdímà is not a DP. nice to have them because of their moons. rumina still doesn't make it. — kwami (talk) 06:09, 7 September 2025 (UTC)[reply]

Alright, those two seem to be pretty notable in their own right, considering their low densities (and the ridiculous name of the former). Thirtyfourninety (talk) 06:35, 7 September 2025 (UTC)[reply]

what about 2007 JJ43? we have it in the template, but in the dp article it's in the 'unmeasured' list with a magnitude of 4.5. in its own article we show a 10 yo measurement of 610+170−140 km. if we keep it in the template, should we move it up to the main list in the DP article? kinda nice that everything in that list currently has at least a nickname — kwami (talk) 08:21, 8 September 2025 (UTC)[reply]