Talk:Sedna (dwarf planet)

Sedna is not a dwarf planet according to the IAU

Sedna is not a planet according to the IAU. Therefore, the first sentence of this article is seriously flawed. It is ironic that everyone believes what the IAU says Pluto is, even though many planetary scientists, such as Dr. Alan Stern, believe Pluto is a planet of the dwarf planet category. In fact, Dr. Neil deGrasse Tyson admitted to Dr. Stern (and I will provide the You Tube link) that dwarf planets are planets. However, no one believes the IAU when it says Sedna is NOT a dwarf planet.

This is from the official IAU website, circa 4/1/22:

Pluto and the Developing Landscape of Our Solar System

Planets, Dwarf Planets and Small Solar System Bodies Questions and Answers

............

Q: How many dwarf planets are there? A: Currently there are five objects accepted as dwarf planets. Ceres, Pluto, Eris, Makemake and Haumea.

As you see, no mention is made of Sedna. The reason it isn't a dwarf planet is that it's not yet been determined, because of its great distance from Earth and the inner solar system whether is has hydrostatic equilibrium.

It should be noted that the IAU still has inaccurate information provided by Eris co-discoverer Mike Brown that Eris is either larger or equal in size to Pluto. In fact, Pluto is roughly 40 kilometers or 25 miles longer in diameter -- the distance of a marathon.

Sowff (talk) 02:14, 2 April 2022 (UTC)SowffSowff (talk) 02:14, 2 April 2022 (UTC)

What does that have to do with the first sentence of this article? The IAU isn't even mentioned. — kwami (talk) 02:30, 2 April 2022 (UTC)

The "officialness" (whatever that means) of IAU's definition doesn't make IAU an absolute authority, as far as Wikipedia is concerned. The fact that the IAU hasn't updated their list of dwarf planets in a long time does not mean that the scientific community as a whole hasn't, or that Wikipedia shouldn't do so. To quote user kwami: "knowledge does not hold still: We should determine whether a body is a DP based on a preponderance of sources, not according to whether the IAU gave its blessing 7 years ago." (That quote is from 2015, and it's still true 7 more years later). There are numerous astronomers who call Sedna a dwarf planet, and so far, the consensus on Wikipedia seems to be to follow that line. See the Classification section. There are some astronomers who have called Haumea's dwarf planet status into question, but that doesn't seem to be a majority position at this time. How Wikipedia handles this can (and will) change, if the consensus in either the scientific community, or among Wikipedia users, changes in the future.
As far as the "hydrostatic equilibrium" criterion is concerned, that has not been of great help, and even the IAU has practically dropped it, switching to a criterion based on absolute magnitude rather than shape. Sedna doesn't meet that new criterion, but that's of little relevance for its physical properties, given that Sedna's diameter has been measured directly. To quote from the Dwarf planet article: "[...] any unnamed trans-Neptunian object with an absolute magnitude brighter than +1 (and hence a minimum diameter of 838 km at the maximum geometric albedo of 1) was to be named by a joint committee consisting of the Minor Planet Center and the planetary working group of the IAU. At the time (and still as of 2021), the only bodies to meet this threshold were Haumea and Makemake. These bodies are generally assumed to be dwarf planets, although they have not yet been demonstrated to be in hydrostatic equilibrium, and there is some disagreement for Haumea." Renerpho (talk) 03:13, 3 April 2022 (UTC)

References

Classification section needs update

The "Classification" section currently isn't up to Featured Article standards. Most of this section was written in 2008, and some of it is no longer factually correct. For instance, the sentence "no other objects have yet been discovered in its vicinity" (introduced in this edit on 16 February 2008) is wrong since 2012 VP113 was announced in 2014. In addition, the youngest source given in this section dates to 2011, and I am sure the consensus within the scientific community has evolved since then.
Maybe the fact that this section is so poorly maintained is sign that there are larger issues throughout the article. I am thinking of requesting a WP:PR for this 2010 featured article, the vast majority of which is more than 10 years old. Renerpho (talk) 03:44, 3 April 2022 (UTC)

I have nominated 90377 Sedna for a featured article review here. Please join the discussion on whether this article meets featured article criteria. Articles are typically reviewed for two weeks. If substantial concerns are not addressed during the review period, the article will be moved to the Featured Article Removal Candidates list for a further period, where editors may declare "Keep" or "Delist" the article's featured status. The instructions for the review process are here. Renerpho (talk) 05:59, 3 May 2022 (UTC)

The article status is 'kept' as of 4 February 2023. Praemonitus (talk) 18:14, 29 September 2023 (UTC)

No "observations" section?

There is a section about the discovery of Sedna, which details early observations (including precoveries). Unfortunately, there is no section where later observations are discussed. User Starcluster has added a piece about recent observations by the TESS space telescope, which I felt forced to remove because they did not fit in the discovery section (diff). I would suggest a section dedicated to (notable) observations. It doesn't have to be long, just a place where interesting observations can be added that don't fit into any of the existing sections. Opinions? Renerpho (talk) 04:50, 3 May 2022 (UTC)

Sounds reasonable. It could also be a "Later observations" subsection of "History". XOR'easter (talk) 16:55, 5 May 2022 (UTC)

On second thought, I'm not sure that we need that subsection. It is rather repetitious to state the fact that so-and-so observed Sedna, and then in a later section say what they found. If they did not find anything of particular note, then what's the case for including them? XOR'easter (talk) 18:02, 26 June 2022 (UTC)

Requested move 14 November 2022

The following is a closed discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. Editors desiring to contest the closing decision should consider a move review after discussing it on the closer's talk page. No further edits should be made to this discussion.

The result of the move request was: no consensus. There is an existing consensus that minor planets that we're relatively certain are dwarf planets should be unnumbered. The wrinkle is the definition of "relatively certain"; Pluto is the only minor planet known to be in hydrostatic equilibrium (although Eris almost certainly is too, and Ceres is "close enough" to have made the Resolution 5A list).

Where we draw the line for Wikipedia purposes is ultimately a subjective matter informed by academic consensus, but at the moment, there is no consensus to move from "only the IAU five are unnumbered". I suggest that a more rigid consensus be formed at WP:SPACE as to naming conventions of possible dwarf planets for WP:NCPLANET, because it's not really desirable to be formulating naming conventions over multiple RMs. (closed by non-admin page mover) Sceptre (talk) 01:00, 22 November 2022 (UTC)

---

• 90377 Sedna → Sedna (dwarf planet)
• 225088 Gonggong → Gonggong (dwarf planet)
• 90482 Orcus → Orcus (dwarf planet)

– Per WP:COMMONNAME, numbers are not usually added to the dwarf planets (see page dwarf planet for example). Adding "dwarf planet" in brackets is a much better disambiguator than the number and more recognisable for most readers. The move will make the titles consistent with Eris (dwarf planet) and Ceres (dwarf planet). For background, the last move request I am aware of was Talk:Ceres_(dwarf_planet)/Archive_7#Requested_move_2_October_2021, which found consensus against adding the number back to the other dwarf planet articles. Vpab15 (talk) 19:29, 14 November 2022 (UTC)

There was also a previous request at Talk:90377_Sedna/Archive_2#Requested_move_24_January_2016 that resulted in no consensus. Vpab15 (talk) 19:43, 14 November 2022 (UTC)

Survey

• Oppose for three very specific reasons: There are FIVE dwarf planets that EVERYBODY agrees on: Pluto, Eris, Ceres, Makemake, and Haumea. (Those are the ONLY ones listed as 100%-undeniably-dwarf-planets by the IAU.) However, there are a bunch of minor planets that are "POSSIBLE dwarf planets" that there's NO complete 100% consensus on: including Quaoar, Orcus, Sedna, Gonggong, and a plethora of others (anywhere between FIVE and ONE THOUSAND TWO HUNDRED). Essentially, these minor planets are different from the main five that are defined by IAU as dwarf planets — in that the IAU five are universally considered dwarf planets, whereas this batch is... less-universally agreed-

The problem with moving these three pages to this title, is (1.) it's debatable whether they should be titled "(dwarf planet)" or "(minor planet)", (2.) WP:CONSISTENCY (i.e. when there's a choice between breaking the established "[number] [name]" format vs keeping it intact, and the "breaking it" option has problems, keep it intact), and (3.) — a way-more-relevant reason —  NOBODY can agree on the boundary of which ones (outside of the IAU five) count as dwarf planets, so if we move these, then someone will suggest moving Salacia, then someone will suggest Varuna and Ixion — and we'll be stuck in a situation of nebulousness where (A.) the established "[number] [name]" format breaks apart even FURTHER and (B.) we can't cleanly draw the boundaries because even the ASTRONOMERS disagree on where to draw the boundaries. We should absolutely keep the other versions as redirects — but without moving the pages. If it ain't broke, don't fix it. Paintspot Infez (talk) 19:49, 14 November 2022 (UTC)

The main question here is what title is best for the average reader. Adding "dwarf planet", even if slightly controversial is much more helpful than a "meaningless" number they won't remember. "Dwarf planet" is used by enough sources to allow us to add it in the title. It is also how the three objects are described in their articles. That has been the consensus here for quite some time. Vpab15 (talk) 20:02, 14 November 2022 (UTC)

The IAU announcing something as a DP in press releases is not the important thing. What matters is whether it actually conforms to the definition the IAU stated. We do not wait for the IAU to announce press releases confirming the status of every new brown dwarf discovered, even though the IAU has stated a definition of "brown dwarf" too. Except that everybody ignores that, because otherwise Ceres and Haumea are also "possible" dwarf planets because it's not certain that they are in hydrostatic equilibrium (doubt for Haumea HE, deviations from HE for Ceres). So instead we indeed look at whether people call it a DP or not. Per some sources I collected at User:Double sharp/Dwarf planets, it looks like Quaoar, Orcus, Gonggong, and Sedna are generally included by astronomers these days, whereas Salacia and below usually aren't. Double sharp (talk) 21:05, 14 November 2022 (UTC)

@Paintspot: Actually, no: astronomers do not agree on those five. Haumea and Makemake were given to the joint planetary/MPC committee to name under the assumption that they were DP's, and the IAU stated that they will retain those names even if it turns out that they are not DPs. And indeed several astronomers have disputed the assumption that they are. Pluto is demonstrated, Eris is assumed because it's more massive than Pluto, Ceres is widely believed to be a DP though there are some problems with that even after Dawn. There's little evidence for the other two either way. — kwami (talk) 21:31, 14 November 2022 (UTC)

Comment – Thanks for the sources and info! I still think I'd oppose, also based on User:Double sharp's comment that also brought WP:NATURAL into play — that it's often preferable to have a natural disambiguation over a parenthetical one. Paintspot Infez (talk) 23:48, 14 November 2022 (UTC)

• Oppose. There is no evidence that these bodies are dwarf planets or at least that they are commonly referred to as such. Ruslik_Zero 20:01, 14 November 2022 (UTC)
  • This is a false statement. See User:Double sharp/Dwarf planets for some sources that do refer to them as such. Double sharp (talk) 21:00, 14 November 2022 (UTC)
• Oppose, but because of WP:NATURAL. Natural disambiguation through use of an alternative name is generally preferred over parenthetical disambiguation. Double sharp (talk) 21:10, 14 November 2022 (UTC)
  • I don't think that is true. Apart from other dwarf planets (Eris (dwarf planet) and Ceres (dwarf planet)) we also have Ganymede (moon) for example, not Jupiter III. Per WP:UCRN we should use the title that is both common and recognisable to the average reader. The current title fails on recognisability. Vpab15 (talk) 19:21, 15 November 2022 (UTC)
    • Comment Correct me if I'm wrong, but "Jupiter III" is so rarely used, I don't think anyone has ever proposed to move Ganymede there. There is no policy to avoid parentheses at all cost. Renerpho (talk) 20:48, 15 November 2022 (UTC)
    • Correct me if I'm wrong, but I don't think Sedna is really that well-known outside people who know something about astronomy. But astronomers do use (90377) as their disambiguation a lot, usually putting the number in the first instance, and then dropping it thereafter, exactly like how we're doing it. I presented eight such papers to Fyunck(click) below: one two three four five six seven eight. Double sharp (talk) 23:53, 19 November 2022 (UTC)
• Support This is really a no-brainer move. These are commonly called dwarf planets and even our own Wikipedia leads say as much. Especially with Sedna. There is nothing magically official about the term dwarf planet used in parenths, but it is the common term used to describe these bodies. Using 90377 Sedna is even more obtrusive to common name than Sedna (dwarf planet). This article name is broken. Someone above said there are five objects everyone agrees with... baloney. Not everyone agrees that Pluto is a dwarf planet. I haven't checked but could Sedna as a planet be the primary topic for this term? Fyunck(click) (talk) 20:12, 15 November 2022 (UTC)
• Support: The first words of the article are " Sedna (minor-planet designation 90377 Sedna) is a dwarf planet. " Ann Teak (talk) 20:24, 15 November 2022 (UTC)
• Oppose, mostly per WP:NATURAL, and to avoid a hassle. Most asteroid articles are named in a similar fashion, like 4 Vesta and 324 Bamberga. We are making an exception for the five official dwarf planets. Here's my take on why we make this exception: I usually don't like "appeals to authority" on Wikipedia. However, since the very question of what is a dwarf planet is so controversial, I think it's wise to use the IAU definition in this instance, as the most official definition there is, and to apply a very strict definition for the purpose of article names (i.e., there are exactly five dwarf planets). If we don't do this then I predict we'll end up with move requests for any asteroid that has been called a dwarf planet by someone. Why not move 28978 Ixion as well? You don't need a crystal ball to see where this leads. Or we could keep applying the simple, if arbitrary, rule that has served us well for so long. Renerpho (talk) 20:48, 15 November 2022 (UTC)
  • Additional request To the closer, or to Vpab15: If the result of this discussion turns out not to move, then please remember to also move back Quaoar. See this discussion on Vpab15's talk page, and this one on the Quaoar talk page. Renerpho (talk) 20:48, 15 November 2022 (UTC)
  • Comment, to add to my vote: Someone mentioned consistency, i.e. WP:TITLECON. I should have mentioned that, too. I guess my argument already goes in that direction, but if you want another policy to go with it, this would be it. Renerpho (talk) 20:56, 15 November 2022 (UTC)
    • I agree. The current situation is an acceptable compromise IMO. I'd personally prefer to have all minor planets with the number, but there's no way WP:TITLECON outweighs the fact that the DP is the obvious WP:PRIMARYTOPIC for "Pluto". Evidently, many others here would like the numbers removed for some other objects. The situation with minor planet numbers for everyone but the 5 the IAU has called dwarfs has been stable for years now and sits midway between these two ideas. I happen to think that whether or not the IAU calls something a dwarf or not is an arbitrary line that doesn't mean much, but as a necessarily arbitrary reason to pick article titles, it seems apropos, and more importantly, seems to have worked. Double sharp (talk) 23:58, 19 November 2022 (UTC)

Discussion

• One thing for sure. If this doesn't move then we need to remove the portion of the lead sentence that says "is a dwarf planet", since that would be factually incorrect and confusing to wikipedia readers. The same with other objects that use the same phrase. Fyunck(click) (talk) 08:38, 19 November 2022 (UTC)

  There's nothing about that that's for sure. It is factually correct that many astronomers call it a dwarf planet and that that kind of consensus of astronomers is precisely how we decide what objects are classified as. So, no confusion. Whether or not "dwarf planet" should be used as the disambiguation for the title is a different story. Mercury is not more of a planet than Earth because it has "(planet)" in the title and Earth doesn't. Double sharp (talk) 14:28, 19 November 2022 (UTC)

  Most of the against arguments here are that it is not officially classified as a dwarf planet. With those arguments, it is "for sure" that we should not be saying right up front in the lead that it is a dwarf planet. That is exceedingly confusing to readers. If consensus is to call it a dwarf planet that that is how it should be listed both as title and the lead. You seem to want to have it both ways, but that is not how it should work and is a disservice to our readers. Fyunck(click) (talk) 20:46, 19 November 2022 (UTC)

  We certainly can have it both ways. The argument made in the discussion is not, in fact, that it is not officially classified as a dwarf planet. We don't care about that on Wikipedia (I certainly don't, as should be apparent from what I said on this talk page in previous discussions). The argument is that, for the sake of consistency, we have to draw a line somewhere when it comes to naming articles, and the IAU definition seems to be the only choice for that line that we can agree on. This is a behind-the-scenes question that has no bearing on what we say anywhere else on Wikipedia. We can use that definition in one instance, and ignore it in another. How does the saying go: "Knowledge is knowing that a tomato is a fruit. Wisdom is knowing not to put it in a fruit salad." Renerpho (talk) 21:07, 19 November 2022 (UTC)

  Like I said: by your logic, we are having it both ways by calling Earth a planet in its lede, but not titling the article as Earth (planet). Double sharp (talk) 21:23, 19 November 2022 (UTC)

  Twisting my words doesn't help your case. In looking at the opposes it is evident that arguments are using the fact that Sedna is not "officially" a dwarf planet. We don't use 134340 Pluto or Pluto (dwarf planet) because simply Pluto as a planet is the most common name (although young kids might disagree). 90377 Sedna is not anywhere near that common. We don't need a disambiguation if another name is really much more common but that is not the case with Sedna. Earth is so common as to be ridiculous that you mentioned it. I think readers would be more likely to expect and look up Sedna (dwarf planet) or Sedna (minor planet) or dwarf planet Sedna, than astronomical designation 90377 Sedna. It is rarely used term when talking about the astronomical object. You think Britannica would use 90377... nope. How about Encyclopedia.com... nope. University of Alabama... nope. At wikipedia we usually plop things at a commonly used name... the only real commonly used terms are Sedna and dwarf planet Sedna. Sedna (dwarf planet) or Sedna (minor planet) are very good candidates for placement here. 90377 is not common. But that is the periphery issue. If the arguments against the title move are that it is not a dwarf planet yet, then those same arguments would apply to not calling it a dwarf planet in the lead. We could call it a potential dwarf planet, but not a dwarf planet. And overwhelming consensus is to call it a dwarf planet in the lead, then Sedna (dwarf planet) is probably the best place for our readers. Fyunck(click) (talk) 22:19, 19 November 2022 (UTC)

  I'm confused about what you think I'm twisting; it's certainly not my intention to "twist". But you said If consensus is to call it a dwarf planet that that is how it should be listed both as title and the lead. Well, consensus is to call the big 8 planets, yet only Mercury has it in the title. That seems to show that the questions about what to call something in the lede and what to call something in the title are two different things. I think that the arguments that Sedna is not "officially" a DP are based on false premises, and that the article should call it a DP because most sources think it is one. Maybe with the caveat "generally considered". (Whether it fits the IAU definition or not is less clear, but everyone's ignoring it anyway: see Haumea.) But I still think the minor-planet number 90377 is appropriate for the title for other reasons. Also, we don't use "134340 Pluto" or "Pluto (dwarf planet)" because Pluto the DP is the WP:PRIMARYTOPIC for "Pluto" and hence does not require disambiguation. Thus, it is not relevant. OTOH, plain Sedna is a disambiguation page. Thus we have to choose what kind of disambiguation to use.

  The minor-planet number is extremely commonly used among astronomers, although usually it is only used the first time, and then dropped in later occurrences (exactly like how we're doing it). E.g. one two three four five six seven eight. It's in the official naming citation and it's used by JPL Horizons. That makes it a perfectly reasonable and recognisable disambiguation for people interested in astronomy, and I doubt Sedna is known very much outside people interested in astronomy. Double sharp (talk) 23:39, 19 November 2022 (UTC)

  Fyunck(click), our convention is to name all asteroid articles with the MPC number, with the relatively recent exception of 1 Ceres. This is true even when a name is unique to that asteroid. There are several asteroids with odd spellings that differ from the spelling of their namesake, so that an online search of the name will return only the asteroid. There are many, many more where there is no other WP article with that name/spelling. Yet their articles all include their MPC number regardless. That convention makes it much easier to cover the thousands of named asteroids. We have something a bit similar with languages, where nearly all of the language articles have the word 'language' appended, even though it's often not necessary per WP's DAB criteria. In both cases, having the superfluous number or word saves a lot of time in tedious arguments about COMMONNAME and avoids clashes if another article under the same name is created [e.g. the people that the language is named after]. There's no reason we can't have exceptions; e.g. Latin, Esperanto and Sanskrit are exceptions among language articles, as for historical reasons Pluto is among minor planet articles. Personally, I might remove the MPC number from the dwarf planets, but the problem there is which those are. There are no 'official' dwarf planets, any more than there are 'official' mammals. Last I heard, the only minor planet we actually know is a dwarf is Pluto, with essentially no dispute about Eris. The problem with putting 'dwarf planet' in as a dab in the title is that we may have RS's that dispute that it is a dwarf planet. In the lead we may say it's a DP, because the most recent refs conclude that's what it is, but scientific consensus may change, and we really don't want to go through this all over again every time that happens. It' much easier to update the lead than to move an article with a disputed name. — kwami (talk) 23:57, 19 November 2022 (UTC)

  Totally agreed with this point. About a decade ago it was generally thought that a lot more objects were likely DPs, but scientific consensus has swung away from that. Having to move all those articles seems so much harder than just updating the articles. For now, Sedna is generally described as a DP by scientists, and we should reflect that; if at some point that ever changes, we should reflect it as well. Double sharp (talk) 00:05, 20 November 2022 (UTC)

  There is "convention" and there is common name and sourcing. I have found out many times at Wikipedia that just because a project uses a convention that it gets overridden by sourcing, common name, and MOS. In the general scheme of the world and all the sourcing I feel you are going to find it much more common to find Sedna dwarf planet than you are to find 90377 Sedna. Much more common. I think if you open this up to a full Wikipedia Rfc, commenters are going to be confused with anyone who uses the argument it's not a dwarf planet yet wants dwarf planet in the lead. And I think you are going to have the general wikipedia population leaning towards "Sedna (dwarf planet)" or "Dwarf planet Sedna" then you are 90377 Sedna. Using "convention" means next to nothing if it's confusing or wrong and many sports projects have recently found their "conventions" buried in RfCs. Fyunck(click) (talk) 07:12, 20 November 2022 (UTC)

  "Sedna dwarf planet" is not a name (or even grammatical). It is the name "Sedna" with something added to tell us which thing called "Sedna" is meant. OTOH, "90377 Sedna" is actually a (formal) name for this object which is unambiguous. Double sharp (talk) 11:51, 20 November 2022 (UTC)

  Fyunck(click), you have repeatedly misrepresented the argument. Assuming good faith, this suggests that you haven't read the comments well enough to know what you're arguing against.

  Yes, the question is whether we wish to make an exception to the well-established convention to use the formal MPC name, followed by thousands of WP articles, for Sedna. IMO, if we do that, we should simply call it 'Sedna' without any disambiguation. Sedna may be a dwarf. It may not be. It is currently considered a dwarf, or assumed to be a dwarf, in a preponderance of sources. Yet there aren't all that many sources that take a position either way, and the dominant position may change at any time. IMO we don't want to freeze an unsubstantiated factual claim into the title of an article. That would like naming our article on a fossil species "X (mammal)" when it's not clear that it is a mammal, just because the most recent sources have concluded that it probably is a mammal. We can say "X is a mammal" in the lead, with the refs to support that, with the understanding that if future sources conclude that it's not a mammal, we will change the lead. We wouldn't want to move the article every time that happens. — kwami (talk) 22:20, 20 November 2022 (UTC)

  Please see WP:CRYSTAL. There is a consensus that the objects in question are most likely dwarf planets. That is why the lede says they are dwarf planets. We can speculate all we want about what future research will say, but for now we need to accept the current available evidence (which will always be incomplete and provisional in this type of research). If it turns out they are not dwarf planets, both the lede and the title can be changed accordingly, it is not a big deal. Vpab15 (talk) 22:34, 20 November 2022 (UTC)

  But why go through all that when there's already a disambiguation by alternative formal name in use, and it can't possibly go through this problem?

  Previous research suggested that there were over 200 dwarf planets. Now only nine or ten (Salacia is ambiguous) are considered likely. It's hardly unreasonable to suspect that the number might shrink further in future, when such speculation has already been done in the literature: Of the trans Neptunian objects, several of the largest bodies have been included alongside the planets Pluto and Charon. This includes the remaining IAU dwarf planets Eris, Makemake, and Haumea as well as Orcus, Salacia, Quaoar, Gonggong, and Sedna. Including these objects and not more was a subjective choice, given the relative confidence that these objects are large and massive enough to have spheroidal shapes. While there may be hundreds and perhaps thousands of trans-Neptunian planets, there is reason to believe that most candidate objects with diameters below 1000 km may be too porous to have reached shapes near equilibrium, given their low densities. This means even trans-Neptunian objects as large as Orcus and Salacia may not be planets. Regardless, more observations are required of these distant, poorly understood objects and the table is certainly open to revision. With current error bars, Sedna could very well also be under 1000 km. The consensus among sources is that it's a dwarf planet according to what we know, but it's also admitted in the literature that that could easily change, because we don't know very much about any of these objects except Pluto and Ceres. (Even for Eris, we don't actually know: it's just that it's the size of Pluto and hence, almost alone among the candidates, not seriously doubted. Even Haumea may not fit the IAU definition!) This is verifiable speculation and does not fall under WP:CRYSTAL.

  I'm aware this doesn't cover Gonggong (which is about the size of Charon which no one seriously doubts), but I think the 1000-km cutoff in here and Grundy 2019 for doubts is a strong enough verifiable argument that we shouldn't move Sedna and Orcus. As for Quaoar, it's a slightly different case because there's no need for disambiguation, and anyway it securely crosses 1000 km (the high end of the consensus cutoffs in RS). Double sharp (talk) 23:24, 20 November 2022 (UTC)

  I don't have much to add to what Double sharp and kwami have said. Just that Quaoar is a bit of an odd case, because Quaoar (deity) is a redirect to Chinigchinix. For many of the other TNOs, the deity is considered the primary topic, and the need for disambiguation arises because, for example, Gonggong and 225088 Gonggong are spelled the same. Renerpho (talk) 13:39, 21 November 2022 (UTC)

  Not directly relevant, but note that Weywot (Quaoar I) is one of only a few moon articles that aren't dabbed with "(moon)", the others being Moon, Enceladus and Ilmarë. — kwami (talk) 20:56, 21 November 2022 (UTC)

  There's also a few small irregulars that are primary topics because their namesakes are sufficiently obscure, e.g. Jupiter XXI Chaldene, Saturn XX Paaliaq. Double sharp (talk) 21:25, 21 November 2022 (UTC)

Note also that the 1000-km cutoff is for being a solid body, not for being a dwarf. A dwarf needs to be in hydrostatic equilibrium; that's not possible if it's not solid, so solidity can partially substitute for HE (necessary but not sufficient).

Saturn's moons suggest that the HE cutoff may be around 1500 km, but that's for icier and rather warmer bodies, so it's likely to be higher for these TNOs. Also, that limit is based on Rhea being in HE, but we don't know whether Rhea is actually in HE or simply despun before it froze out of HE. (It's closer to Saturn than Iapetus is, so would have despun earlier in its history.)

The only bodies we can confidently say are DPs are Pluto and Eris. Even Ceres is doubtful and IMO should be moved back to 1 Ceres; we certainly shouldn't move any more. — kwami (talk) 20:18, 21 November 2022 (UTC)

Tethys is 1060 km, but its solidity has been doubted, so the 1000 km solidity cut-off may also be too low for TNOs. With current error bars, even Quaoar might not cross 1.5 g/cm³. Post-Cassini modelling suggests that Iapetus collapsed out its initial porosity, but Tethys might not have. At least we know Makemake and Haumea have densities high enough to be solid.

I agree that Ceres is doubtful. Maybe I should've just proposed that one last year and not Makemake and Haumea (which are already the primary topics). But since everyone's calling it a DP for now, it can probably wait since it's been stable at that title for a while. Also, IIRC Ceres was included in the original concept of what a DP is. So, I suspect that if it turned out not to be a DP, astronomers would just start ignoring the definition. After all, they already do that when calling Mercury a planet (it's far from hydrostatic). Double sharp (talk) 21:25, 21 November 2022 (UTC)

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

Potential or likely dwarf planet

Per official sources and our own Wikipedia article on Dwarf planets, saying right up front in the lead sentence that Sedna is a dwarf planet is misinformation to our readers. It's a likely dwarf planet, it's a potential dwarf planet, but it has not been officially designated as such whether you look at Britannica, or Universe Today, which use the terms candidate or potential. Since we aren't sure it should be either removed or have potential or possible or likely added. I added the term potential but it was reverted. This is very debatable for Sedna. Fyunck(click) (talk) 07:43, 22 November 2022 (UTC)

There is no such things as "official sources" or "official designation". That's not how science works. We have several RS's that Sedna is a DP. If you have RS's that Sedna is not a DP, please provide them. — kwami (talk) 09:56, 22 November 2022 (UTC)

BTW, Brittanica (a 3ary source) doesn't address the issue, while if we were to follow Universe Today (not a RS), we would need to characterize "Haumea, Makemake, and Eris" (and presumably Pluto) as "potential" DP's as well. Again, no reason to single out Sedna. — kwami (talk) 10:01, 22 November 2022 (UTC)

In general, we consider objects to be dwarf planets, brown dwarfs, or whatever else if the astronomical community generally accepts that they meet the definition, and not if it has been added to an official list (which doesn't even exist for the brown dwarfs). It's generally agreed among astronomers that Sedna is a DP according to current knowledge. That is not changed by the fact that they also agree that future updates in knowledge could very well change that. Double sharp (talk) 11:15, 22 November 2022 (UTC)

@Kwamikagami:I supplied two on the talk page right off the bat. That should be sufficient for us to write a more balanced sentence. I didn't say we had to remove it, but at least inform our readers that it is more potential than reality. Are there more RS's.... sure are! We have Discover Magazine, and we have Physics.org. What I'm saying is there are enough sources that do not call it a dwarf planet that we should not sit there in the first sentence and call it one. This is one of those half-truths that make Wikipedia a problem for classroom usage. It stretches definitions to what we like rather than what actually is. Some call it a dwarf planet and some do not so we should not take sides but rather call it as it is. We can say that some say it is a dwarf planet, that it is likely a dwarf planet, that it is potentially a dwarf planet, etc. But we should not use "it is a dwarf planet." We can't go by what "we" at wikpedia consider... we go by sources whether they are journals, magazines, newspapers, etc...and those sources are divided. We should not be so crystal clear and definitive in the lead as to call it a dwarf planet. Fyunck(click) (talk) 19:20, 22 November 2022 (UTC)

Britannica did not include the term "dwarf planet" at all. Universe Today calls Eris a "potential dwarf planet" when nobody is actually disputing it in the literature. Discover magazine says it's going to give "a rundown of some of the most potentially exciting and unexplored dwarf planets", includes Gonggong (as 2007 OR₁₀, since it was unnamed then) in that list, then calls Gonggong a "dwarf planet candidate", and simultaneously includes a NASA video calling Gonggong outright a "dwarf planet". (And it also includes Triton in its list, which as a moon of Neptune cannot be a "dwarf planet". And it even admits that under its entry! And it also calls Quaoar and Orcus unqualified "dwarf planets" even though it started off by claiming that the IAU only recognised Ceres, Pluto, Haumea, Makemake, and Eris.) And it also seems to think the IAU has to formally recognise dwarf planets even though there is no actual formal process for it to do so. Phys.org again calls Eris a "potential dwarf planet". So what you've presented is one source that takes no position, one source that seems to be very confused, and two that show more doubt about objects than any actual astronomers do. Those seem less like new positions and more like cases of the popular-facing press being confused. (Except Britannica, which isn't confused, just irrelevant to the discussion.) Double sharp (talk) 19:45, 22 November 2022 (UTC)

This omission stuff is getting rather strange. You said Britannica doesn't include dwarf planet at all.. This is true it uses "small body." But what you failed to look at is that Britannica places Pluto and Ceres in the category of dwarf planet. That speaks volumes. And that universe today links says "Sedna was discovered in 2003 by Caltech astronomer Mike Brown and his team, and was one of a series of potential dwarf planets" and also "What really sets Sedna apart from the other known dwarf planet candidates is its enormous orbit." There is also a graph on the page that says "The orbit of dwarf planet candidate 90377 Sedna (red) compared to Jupiter (orange), Saturn (yellow)...". How could you miss that? Are you purposely trying to bend this to your will? I'm confused how those items could be missed and you should strike what you wrote as non-factual. Fyunck(click) (talk) 20:16, 22 November 2022 (UTC)

Britannica doesn't have entries for Orcus and Quaoar, so we can't know very much about what it thinks for bodies comparable to Sedna in size. It is also a tertiary source. The Universe Today link, as I said, also considers Eris a "potential dwarf planet". Since no astronomers actually doubt that one, I see no reason to take it seriously as an RS. Double sharp (talk) 20:31, 22 November 2022 (UTC)

Pop-science media runs the gamut from "acceptable" to "garbage". Most of it is garbage. We should not be writing articles by sweeping garbage into a pile. The default presumption should be that these magazines are bad — we need a solid reason to include them, not to exclude them. XOR'easter (talk) 15:18, 23 November 2022 (UTC)

Okay, of your two additional sources, Discovery is not a RS, and Phys.org is a duplicate of Universe Today which says that Brown discovered a series of potential dwarf planets like Eris. Should we say that Eris is a 'potential' dwarf planet based on that? — kwami (talk) 20:39, 22 November 2022 (UTC)

I guess I missed that Discovery Magazine is unreliable. I don't see it in the do not use sections of WP:RELIABILITY. Could you point that out to me? Fyunck(click) (talk) 22:03, 22 November 2022 (UTC)

A source that contradicts itself is ipso facto not reliable. Double sharp (talk) 22:15, 22 November 2022 (UTC)

As I said... you need to point out the fact that wikpedia looks at Discovery Magazine and Universe Today as unreliable sources. And I guess the Canadian Space agency as well. And Astronomy.com, and the Lowell Observatory say there are only five. I guess those are also unreliable sources. You are cherry picking the sources you like and throwing out the ones you don't. I'm not. I say we take them all and come up with a lead that makes sense and is truthful to our readers. Fyunck(click) (talk) 22:59, 22 November 2022 (UTC)

CSA only says that the IAU recognises five and that it is "the authority on the naming and classification of celestial objects". This is yet again the same misunderstanding, because the IAU is not in the business of doing such recognitions. I don't throw out sources because I don't like them, but because they flat-out contradict what astronomers say and the presence or absence of actual IAU processes.

If sources that contradicted themselves were reliable, then they could be used both to back up the statement X and the statement not-X. This obviously makes no sense. Double sharp (talk) 23:05, 22 November 2022 (UTC)

That may mean when first discovered, no one was quite sure what things like Eris were. Ann Teak (talk) 21:17, 22 November 2022 (UTC)

On the contrary, everyone was sure then and is sure now that Eris is in hydrostatic equilibrium. (It's more massive than Pluto, which we know is in HE; and back then people also thought it was larger.) The term "dwarf planet" had already been formulated by Alan Stern when Eris was discovered, though others used different names for the notion; the only question was whether dwarf planets should be a subcategory of planets or not. Whether Eris fit the definition was never under question. Double sharp (talk) 21:26, 22 November 2022 (UTC)

The content in the lead (both before and after Fyunck's edit) does not reflect the content in the body; regardless of where each of you stand on this matter, the lead must reflect the body, which is clear that astronomers are divided. I suggest rather than arguing back and forth, an attempt to hammer out a lead which reflects the actual controversy would be more productive. Short of that, the article is likely to lose FA status. The methodology we used at Wikipedia talk:Featured article review/J. K. Rowling/archive1 might be useful. Introducing the vague word "potential" does not solve the matter, in fact, adds more confusion to the lead, as the average reader-- seeing the first sentence-- will have no idea why that is there. My suggestion is to not introduce the controversy at all in the first line, rather dedicate a paragraph or a few sentences to it later in the lead. SandyGeorgia (Talk) 15:54, 22 November 2022 (UTC)

Well, we don't actually have any text or cite any sources saying that it shouldn't be called a "dwarf planet", only that various other terms that do not exclude "dwarf planet" status have also been proposed. In other words, I don't think the situation can really be called a "controversy", and I'm happy enough with "dwarf planet" in the first sentence without further qualifiers. I considered changing the opening line to something like Sedna (minor-planet designation 90377 Sedna) is a trans-Neptunian object often termed a dwarf planet. Currently in the innermost part of its orbit, Sedna is still in the outer reaches of the Solar System... But, I'm not convinced that is necessary. XOR'easter (talk) 18:06, 22 November 2022 (UTC)

I agree with XOR'easter. The body actually points out that astronomers aren't really divided: To be a dwarf planet, Sedna must be in hydrostatic equilibrium. It is bright enough, and therefore large enough, that this is expected to be the case,^[77] and several astronomers have called it one.^[e] (And so far as I can see, those that don't call it one aren't arguing that it isn't one; they're just not using the term "dwarf planet" at all.) So as we can see, astronomers generally agree that Sedna is a dwarf planet according to current knowledge. Some have pointed out that future research might change that (or it might not), but that is not a current controversy because we don't have that future research yet (and the source I linked to above for that doubt about future research includes Sedna as a geophysical planet anyway). It's merely a reflection of the fact that we don't know very much about it right now. If we were writing in 1950, would we cast much doubt on Pluto's planetary status? Or Ceres' if we were writing in 1810? So it seems accurate to call it an unqualified dwarf right now, and change it if future research really does suggest that it isn't one. Double sharp (talk) 18:27, 22 November 2022 (UTC)

Really? This is a science article and the argument you are using is we don't have "any sources saying that it shouldn't be called a "dwarf planet"?" Those sources are calling it a potential dwarf planet and a likely dwarf planet. Sources are calling Ceres and Pluto dwarf planets. It is not accurate at all to call Sedna an unqualified dwarf planet. Those examples of 1810 and 1950 were accurate at the time, and things changed. Sedna's status is not even accurate now. It is best to classify it in a large group of potential dwarf planets for our readers, and not mislead them in any way. I'm beginning to think this should be opened up to wikipedia as a whole with an RfC. I hesitate because outside the astronomy project wikipedia editors may want the sentence removed rather than adding potential or likely or even "some sources". I'm flexible on the wording other than the definitive "it is a dwarf planet." Fyunck(click) (talk) 20:33, 22 November 2022 (UTC)

They are too obviously confused to be seriously considered reliable, as evidenced by two of them calling Eris a "potential" dwarf planet, one of them alternating rapidly between including and excluding Gonggong, and another of them not having the term "dwarf planet" in it at all. Surely it's better to get the information directly from the astronomers rather than rely on however the information has been garbled in the popular-facing press? Double sharp (talk) 20:42, 22 November 2022 (UTC)

It is a dwarf planet according to RS's, which you haven't found. You have found non-RS's that Eris is a 'potential' DP. If you can find a RS that Sedna is still in doubt, by all means share it with us. — kwami (talk) 20:42, 22 November 2022 (UTC)

Those are generally considered reliable sources by wikipedia. I see nothing to the contrary but I admit I could have missed it. Can you point those out because otherwise it falls in the category of WP:IDONTLIKEIT therefore it's not reliable. Fyunck(click) (talk) 22:03, 22 November 2022 (UTC)

Sources that contradict themselves or make provably false statements are obviously unreliable for those statements, even if in general they aren't. That includes any source saying that the IAU is the final arbiter for what is a dwarf planet and what isn't, since there is no such IAU process and that's literally not how it works for any other term the IAU has given a definition for. Analogously, the fact that even now you can still find sources giving lawrencium's symbol as Lw does not mean it should be mentioned as a correct alternative, because per the relevant explicit authority (IUPAC, basically the analogy to the IAU for chemists) it is not. Double sharp (talk) 23:10, 22 November 2022 (UTC)

Precisely what kwami said. I can't speak for anyone else, but all I want is some astronomer's reasoned opinion in a journal against Sedna being a DP. Then I will be very happy to say that Sedna is disputed in the literature. After all, that is exactly what has already happened for somewhat smaller Salacia, and I have no problem at all with its lede that summarises the controversy for that TNO. But I haven't seen anything like that for Sedna. Personally, I doubt Sedna and Orcus, but I'm not an RS. Double sharp (talk) 20:45, 22 November 2022 (UTC)

I doubt that Haumea or Makemake are DP's either. I fully expect that there will prove to be only 3 dwarfs in the SS, but it's quite possible that we won't be able to determine that until we get space missions to the major TNOs decades from now. Even that may not be enough to decide the issue. Unless of course the IAU changes the definition of DP between now and then, or the current definition becomes obsolete because it's unworkable. — kwami (talk) 01:35, 23 November 2022 (UTC)

Sure, but I tend to think about it with the implicit definition Grundy et al. seem to be using, rather than the IAU definition: a DP must be solid and round. The densities suggest that this is quite surely the case from Gonggong and Charon upward, with some slight doubt (but not too much) for Quaoar. If we talk about hydrostatic equilibrium, then even Titan has been doubted, so Pluto might well stand in splendid isolation. :) Double sharp (talk) 11:25, 23 November 2022 (UTC)

Arguing back and forth is not going to resolve the core issue at this article. The lead states that "Sedna (minor-planet designation 90377 Sedna) is a dwarf planet"; I am unable to find any such statement in the article, much less a sourced statement in the article, saying same. Perhaps I missed it. Where is it cited in the article that Sedna is a dwarf? The article says that some astronomers consider it a dwarf and lays out that other bodies call it other things. A methodology (RFC, proposals, or whatever) is needed to resolve this matter before the article can be kept at FAR. The article is not in keep territory, and I hope someone will take the lead on resolving the first sentence of the lead that states something in Wikivoice that is not stated or sourced anywhere in the article. I have suggested the method of successive proposals we used at J. K. Rowling -- a much more contentious article -- that led to consensus. Good luck, unwatching, as I am not seeing discussion here proceeding in a way that will lead to a consensus, and this is not my FAR. SandyGeorgia (Talk) 15:39, 23 November 2022 (UTC)

@SandyGeorgia: I've done some rephrasing at 90377 Sedna#Classification to make the astronomical position clear and put the citations in the main body rather than in the note. I have also tried to make it clear that all these "other things" that people call Sedna do not exclude it being a dwarf, because dwarf planethood is about the intrinsic properties of an object whereas the other classifications mentioned are about where the object orbits. Pluto is simultaneously a dwarf planet, a trans-Neptunian object, a Kuiper belt object, and a plutino. Incidentally, thanks for this comment – I didn't realise that they might be interpreted as mutually exclusive categorisations without an explanation, probably because I remember the meanings of the terms a bit too well. :) I hope my rewording has clarified things! Double sharp (talk) 16:41, 23 November 2022 (UTC)

I found it evident enough from the previous version, but I do think that making the point more explicit is a good move. XOR'easter (talk) 17:46, 23 November 2022 (UTC)

Thx for the ping, as I have unwatched ... this sounds like an improvement, if it sticks. But I leave it to all of you; not my field ... I only want the lead to be supported by the body. SandyGeorgia (Talk) 18:47, 23 November 2022 (UTC)

Kwamikagami has just made some further improvements that I'm happy with. Double sharp (talk) 21:54, 23 November 2022 (UTC)

But it is still under discussion as not supported by sources to the the point an encyclopedia can call it a dwarf planet. If it remains that definitive we should write up a full rfc for all wikipedia to look at, because I don't think the finality is supported by sources. Fyunck(click) (talk) 04:47, 28 November 2022 (UTC)

You're welcome to make a RfC, though it should be for all dwarfs, not just Sedna. — kwami (talk) 07:58, 28 November 2022 (UTC)

That would be ridiculous. We are talking Sedna here not the overwhelmingly sourced five dwarf planets. And yes, I will form a wiki-wide (not just astronomy) RfC on a false lead statement. Consensus cannot stand the scrutiny of sources and editorial opinion just because a wikiproject likes it. Fyunck(click) (talk) 10:45, 28 November 2022 (UTC)

I think he's refering to 50000 Quaoar, 90482 Orcus and 225088 Gonggong, all of which have the same issue. Serendi^podous 10:50, 28 November 2022 (UTC)

That would be understandable, however I don't know how many other potential dwarfs at wikipedia have their lead stating as definitive fact that they are absolutely a "dwarf planet." Do you have a wikipedia listing of those outside the five? I have no issue adding them with a list of sources (books, magazines, newsprint) that do not include them as dwarf planets. An RfC might conclude to strike the sentence entirely and use something like trans-Neptunian small body, or something more generic rather than what I would prefer with "likely" or "potential" dwarf planet. That'll be for the rest of wikipedia to decide and not just a handful of us. Fyunck(click) (talk) 11:30, 28 November 2022 (UTC)

[outdent] Nope. Those are the only ones. None of the smaller possible DPs are so described and I trust Kwami enough not to make the case for anything smaller. Serendi^podous 12:01, 28 November 2022 (UTC)

For goodness' sake. The sources in the article say:

• [1]: The dwarf planet (90377) Sedna is one of the most remote solar system objects accessible to investigations. ... It is the most remote solar system object accessible to direct investigations and belongs to the category of dwarf planets.
• [2]: We have used the SMARTS 1.3m telescope extensively to photometrically characterize the new dwarf planet population (including Eris and Sedna) discovered with the QUEST camera.
• [3]: Efforts to place in context several new discoveries of trans-Neptune dwarf planets, such as Sedna and Haumea, are probing collisional physics in the ice-rock parameter regime as well as the role of dynamical chaos or possibly undetected massive perturbers at the edge of our solar system.
• [4]: puts Sedna in the 'List of "Dwarf Planets"', under "Case II – Sphere or MacLaurin ellipsoid with small albedo spots". Incidentally, this one also reinforces kwami's point a little: under "Case I – Direct measurement of the shape" only Ceres, Pluto, and Eris are listed. So even if we adopt a legalistic view of the definition (direct verification) far beyond what astronomers use in practice, Haumea and Makemake would not be on the same level as those three. There is no way you get five uncontroversial DPs unless you read unreliable popularisations that are confused about what the IAU does and does not do.
• [5]: Sedna ... dwarf planet? near certainty (and in case anyone wants to lawyer about that, Pluto is also only written as "near certainty")

And I've collected even more at User:Double sharp/Dwarf planets.

There is no "discussion" in the literature, astronomers are convinced that Sedna is a DP. There is just confusion in unreliable sources, as we have previously demonstrated. If you want to see a case where there is actual "discussion" in the literature, look at Salacia, and indeed we don't call it a DP in wiki-voice (we do list it as a candidate though). I also note that when you left the discussion for five days, suddenly there were no complaints anymore. So, please: stop WP:BLUDGEONing based on unreliable sources. Double sharp (talk) 14:38, 28 November 2022 (UTC)

They are only unreliable because you don't like them. Wikipedia looks at them as generally quite reliable. I also left because I couldn't follow as much during Thanksgiving. And I only care about our readers and not giving them inaccurate information when we can do better. I don't give a fig about you calling them complaints. That's your problem not mine since it's not like there are 100 editors all telling me we want to keep inaccurate info... it's a couple. You don't own the article but Wikipedia as a whole does, so I'll write it up and let everyone decide, and then I'll go away. Fyunck(click) (talk) 19:40, 28 November 2022 (UTC)

Per WP:SOURCETYPES, When available, academic and peer-reviewed publications, scholarly monographs, and textbooks are usually the most reliable sources. Wikipedia does not need to list all the unreliable sources in the whole world for them to be classified "unreliable". Observing that they contradict themselves or make false statements is obvious enough evidence. Double sharp (talk) 21:22, 28 November 2022 (UTC)

I concur. Honestly, the burden is on anyone who wants to argue that a pop-science media item is good. XOR'easter (talk) 22:10, 28 November 2022 (UTC)

Longest orbital period?

The article says that Sedna has the longest orbital period of any known object in the Solar System of comparable size or larger, at about 900 km. That's technically correct, because there are only about five minor planets that are larger than Sedna, all with shorter orbital periods. However, I don't think that's what this sentence was originally written for. When this was added around ten years ago, the only exceptions were comets. No object larger than a few kilometres was known in such a distant orbit, and it was probably phrased this way to exclude those objects specifically.

The phrase "of comparable size or larger" is ambiguous. Before User:Kheider has changed it today to "remove the tiny rock",[6], it said Sedna has the second longest orbital period of any known object in the Solar System of comparable size or larger (after Leleākūhonua). One could argue that this is wrong because Leleākūhonua is considerably smaller than Sedna, but it is still a sizable object (about 200 km in diameter), not a tiny rock by any means. Still, Kheider is right that this was technically not true.

I think we need to rephrase this paragraph. Renerpho (talk) 12:22, 31 October 2023 (UTC)

I would say anything 200km in diameter is a better giant comet than dwarf planet candidate. And if we are going to include 200 km objects (that make better comets than planets) we have to include 2014 FE72. -- Kheider (talk) 12:34, 31 October 2023 (UTC)

a better giant comet than dwarf planet candidate -- Is that so? The smallest object known to be in hydrostatic equilibrium, Mimas (396 km), is closer in size to Leleākūhonua (220 km) and 2014 FE72 (270 km) than to Sedna (995 km). Dynamically, Leleākūhonua is probably closer to Sedna than to any kind of comet. I'm honestly not sure where to draw the line. My first thought was to only include objects that are observable from a large distance, but that doesn't work. Some comets like Hale-Bopp would qualify by that logic, and I don't think it's reasonable to include that.

I am not completely opposed to the idea that we only mention Sedna, but I think that the phrase "of comparable size or larger" is too vague. Renerpho (talk) 13:27, 31 October 2023 (UTC)

I have dropped the word "comparable", and required the comparables to be the same size or larger. This rules out weirdos like 95P/Chiron (IF it was on a 12k+ year orbit) and what size it too small to consider C/2014 UN271. -- Kheider (talk) 14:09, 31 October 2023 (UTC)

Not ideal but I guess it will do. Renerpho (talk) 15:18, 31 October 2023 (UTC)

Requested move 6 June 2024

The following is a closed discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. Editors desiring to contest the closing decision should consider a move review after discussing it on the closer's talk page. No further edits should be made to this discussion.

The result of the move request was: moved. (closed by non-admin page mover) BilledMammal (talk) 21:22, 13 June 2024 (UTC)

---

• 90377 Sedna → Sedna (dwarf planet)
• 225088 Gonggong → Gonggong (dwarf planet)
• 50000 Quaoar → Quaoar

– As per:
1. WP:COMMONNAME – these objects are frequently referred to as dwarf planets and other similar labels in popular communications ([7] [8] [9] [10] [11])
2. WP:CONSISTENT – consistency with other dwarf planet articles (e.g. Pluto and Eris (dwarf planet))
3. – Sedna (dwarf planet), Gonggong (dwarf planet), and Quaoar each exist and already redirect to their respective primary articles
4. – To reflect astronomical consensus (see List of possible dwarf planets#Likeliest dwarf planets). Per consensus, they are all universally referred to as dwarf planets in relevant Wikipedia articles (e.g. Solar System#Trans-Neptunian region, Dwarf planet, and Wikipedia:Featured topics/Dwarf planets). In particular, recent observation establishes these three as self-differentiated planetary objects ([12] [13]).

It should be noted that although these dwarf planets are not a part of the "official" IAU roster of dwarf planets, the IAU has been known to align with astronomical consensus in reports (e.g. this report[14] about Quaoar's rings)

Finally, I am not listing 90482 Orcus as there was a recent discussion over whether astronomical consensus considered it a dwarf planet. Though it is indeed demonstrably a "consensus" dwarf planet, it likely warrants its own separate move discussion. ArkHyena (talk) 20:27, 6 June 2024 (UTC)

Note 1 – there have been two prior move discussions at Talk:90377_Sedna#Requested_move_14_November_2022 and Talk:90377_Sedna/Archive_2#Requested_move_24_January_2016; both resulted in no consensus. ArkHyena (talk) 20:32, 6 June 2024 (UTC)

Note 2 – Renerpho has opened up a separate discussion regarding his alternative proposal (see below) at Wikipedia_talk:Naming_conventions_(astronomical_objects)#Proposed_change_to_minor_planet_/_dwarf_planet_page_titles; the discussion is currently open. ArkHyena (talk) 21:55, 7 June 2024 (UTC)

• Support. The present naming, with this ridiculous looking minor planet numbers, does not reflect common usage at all. We agreed the dwarf planet making scheme like 18 years ago or something and it's about time these caught up.  — Amakuru (talk) 21:38, 6 June 2024 (UTC)

Support per @Amakuru Killuminator (talk) 00:22, 7 June 2024 (UTC)

• Support, per COMMONNAME. The number is not widely used and having it in the title just serves to confuse readers. Vpab15 (talk) 08:01, 7 June 2024 (UTC)
• Support - On top of all the good arguments above, its just a more likely and easier search term. Sirfurboy🏄 (talk) 08:48, 7 June 2024 (UTC)
• Oppose (or conditional support per my alternative proposal below) - Not much has changed since this question was last discussed. There are a lot of articles about minor planets, like 4 Vesta or 324 Bamberga, that use the full name (including the number). That is how minor planet articles are generally named. While I am sure that some of us would like to see the numbers removed from all of those, I think there is still consensus to keep them in most cases (if not then this move request is made in the wrong place). For exceptions to that rule, it thus becomes a question of WP:TITLECON vs. WP:PRIMARYTOPIC and WP:COMMONNAME. We cannot avoid making an arbitrary line somewhere (we should all be clear about that). Right now, we are drawing that line at the five official IAU dwarf planets. As I said in the 2022 discussion, I don't care about IAU's position per se, and neither does Wikipedia in general, but this has been a controversial question in the past, and the simple rule of naming those five objects differently from all the others has proven useful. We can change our approach, but we should be clear about the consequences: Less consistency, not more (as claimed in the proposal), and the need for case-by-case decisions, possibly revisited whenever the perceived scientific consensus swings. That is a hassle. ArkHyena have already mentioned 90482 Orcus. There are other examples where the title move could prove complicated/controversial, and I gave some in the 2022 discussion. On a different note: For many TNOs, the deity is considered the primary topic, hence why the requested move would result in a need for disambiguation -- Gonggong vs. Gonggong (dwarf planet). Quaoar is a bit of an odd case, because Quaoar (deity) redirects to Chinigchinix, but it is the only exception. Most of the proposed moves would not be WP:NATURAL. Renerpho (talk) 11:04, 7 June 2024 (UTC)

Alternative proposal by Renerpho (discussion moved to Wikipedia talk:Naming conventions (astronomical objects))

Alternative proposal -- One thing that actually has changed since 2022 is that Wikipedia:Featured topics/Dwarf planets has become a featured topic. I would agree if we decide to move our "arbitrary line" from the IAU list to whatever articles are presently on that FT. Inclusion in that list (as well as removal from it) adds quite a high bar for articles to pass, but maybe not as high as IAU's list, and more importantly, a bar that is in Wikipedia's own hands. It also would ensure self-consistency within the encyclopedia. Under the condition that we adopt this as policy, my vote can be counted as a conditional support. In practice, this would have the same result as the original proposal, at least for now. The FT list currently includes the three objects from ArkHyena's proposal, but not Orcus. 90482 Orcus is rated a good article, so it could be included in the FT (is there any discussion about it?). Under my proposal, it would then automatically be renamed to Orcus (dwarf planet). Should an article be removed from the FT list, it would have to be renamed to add back the minor planet number (unless, of course, we decide then that an exception is warranted). Renerpho (talk) 11:38, 7 June 2024 (UTC) @ArkHyena: Would you be fine with that? @Amakuru, Killuminator, Vpab15, and Sirfurboy: You already voted for the original proposal; what do you think about the alternative? Renerpho (talk) 11:51, 7 June 2024 (UTC) @Renerpho: what exactly is the alternative proposal, in practical terms? Where do you propose moving the three articles listed above?  — Amakuru (talk) 11:56, 7 June 2024 (UTC) @Amakuru: Exactly the same move as proposed, just for different reasons (and with possible effects on other articles in the future). Renerpho (talk) 11:57, 7 June 2024 (UTC) @Amakuru: The intention is to replace the current arbitrary line (as described in my vote) with a still arbitrary, but better one, and to avoid unnecessary case-by-case decisions in the future. Renerpho (talk) 12:03, 7 June 2024 (UTC) I do like this alternative proposal, particularly since any additions to it would require a discussion over the subject's status. I do have some concerns over what would happen in the event any of the dwarf planet articles are, for whatever reason, demoted from GA/FA. However, this is an unlikely scenario and I'm assuming this arbitrary line would be treated more as a stable reference rather than absolute policy, so this may not be a problem. ArkHyena (talk) 20:23, 7 June 2024 (UTC) @ArkHyena: Thanks -- yes, that's the idea (more directly linking the name to the content). Regarding your concerns: There is no absolute policy. The default, per my proposed policy, would be to rename it to the standard "number+name" format. However, I'd like to think that, in the unlikely event of a demotion, the question "should we rename it then?" would be asked before the page is moved, if the new title hadn't already been agreed on during the preceding discussion. If it's decided that the "dwarf planet" title should be kept then that's what happens. Renerpho (talk) 20:42, 7 June 2024 (UTC) I have proposed a change to Wikipedia:Naming conventions (astronomical objects). Since my alternative proposal would have the same immediate effect as the original, I think that further discussion of it should probably happen there. How my vote should be counted would of course still depend on the outcome of the discussion over there (and it remains "oppose" until then). Renerpho (talk) 21:36, 7 June 2024 (UTC)

• Support per the reasons give above and because the new titles are concise, simpler and sufficient.

InTheAstronomy32 (talk) 18:25, 7 June 2024 (UTC)

• Support per conciseness. 4 Vesta is readable, 90377 Sedna is very much not. Regarding dwarf planet status, we should reflect consensus in reliable sources (which points towards them being dwarf planets), rather than IAU decisions. Quaoar can even skip the whole "is it a dwarf planet" discussion by being moved straight to Quaoar. Chaotic Enby (talk · contribs) 21:50, 7 June 2024 (UTC)

  Also, support alternative proposal (which somehow got hatted), provided that both the list and the naming convention try to stay consistent with, well, reliable sources. Every line that can be drawn is arbitrary, but we should reflect the one that the sources draw. Chaotic Enby (talk · contribs) 21:52, 7 June 2024 (UTC)

• Support of both the original proposal and Renerpho's alternative proposal. AstroChara (talk) 22:11, 7 June 2024 (UTC)

@Chaotic Enby and AstroChara: Thanks for your support. "Which somehow got hatted" -- that was my own doing. Since the alternative proposal is about a change to the policy, not the requested move, the discussion has been moved to the appropriate policy talk page. I'll copy your votes to comments there if you don't mind. I have linked the second discussion, so hopefully any further discussion about it will take place in the appropriate place. Renerpho (talk) 22:40, 7 June 2024 (UTC)

Thanks a lot, going to take a look at it! No problem with copying my vote. Chaotic Enby (talk · contribs) 22:43, 7 June 2024 (UTC)

No problem here either. AstroChara (talk) 01:56, 8 June 2024 (UTC)

• Oppose for various reasons explained elsewhere, but most importantly, this discussion should be held at wikiproject astronomy. We shouldn't be deciding the name of the Quaoar article on the talk page for Sedna. — kwami (talk) 23:30, 7 June 2024 (UTC)

  This is a multi-page move request, which, as per WP:RMPM, is to be formatted as so:

  A single template may be used to request multiple related moves. On one of the talk pages of the affected pages, create a request and format it as below. ArkHyena (talk) 23:33, 7 June 2024 (UTC)

  As far as I can tell, this move request was formatted correctly, and is done in the correct place. Choosing the Sedna article was reasonable, given that the 2022 requested move for the very same selection of articles has also been discussed here. There are notifications at all the relevant pages, so anyone who is watching any of the affected articles will have been notified. In addition, while not necessary, there actually has been a post about the proposed move on the talk page of the Astronomy wikiproject. Renerpho (talk) 23:54, 7 June 2024 (UTC)

• Oppose for four reasons listed above in the previous discussion. The problem with moving these three pages to this title, is (1.) it's debatable whether they should be titled "(dwarf planet)" or "(minor planet)", (2.) WP:CONSISTENT (i.e. when there's a choice between breaking the established "[number] [name]" format vs keeping it intact, and the "breaking it" option has problems, keep the consistency option intact), (3.) WP:NATURAL (i.e. when there's a choice between natural disambiguation and parenthetical disambiuation, natural disambiguation is often preferred), and also (4.) there's the "official" roster of the five listed by the IAU as dwarf planets (Pluto, Eris, Ceres, Makemake, and Haumea), and also a bunch of minor planets that are "POSSIBLE dwarf planets" that there's not a complete consensus on: including Quaoar, Orcus, Sedna, Gonggong, and a plethora of others (anywhere between FIVE and ONE THOUSAND TWO HUNDRED). If we move this batch of "maybe"s, then someone will suggest moving Salacia, then someone will suggest Varuna and Ixion — and we'll be stuck in a situation of nebulousness where (A.) the established "[number] [name]" format breaks apart even FURTHER and (B.) we can't cleanly draw the boundaries because even some astronomers disagree on where to draw the boundaries of the "official" roster. Heck, there's even debate that some of the "official" five are only "possible" dwarf planets, which makes it even clearer that the category of "dwarf planet" has some really (no pun intended) nebulous boundaries. We should absolutely keep the other versions as redirects — but without moving the pages. If it ain't broke, don't fix it. Paintspot Infez (talk) 19:52, 9 June 2024 (UTC)
  • Not even the IAU actually sticks to 5 dwarfs. They called Quaoar a dwarf in a 2023 annual report. Based on current studies, no one seriously doubts Quaoar, Sedna, or Gonggong, at the very least; and Orcus is generally accepted. Double sharp (talk) 14:34, 11 June 2024 (UTC)

  I'm unsure how Quaoar, Orcus, etc. do not have a "complete consensus". It should be noted that these objects are very clearly held as dwarf planets by a large portion of the astronomical community with little to no dispute. The same cannot be said for objects such as Salacia, 2002 MS4, and smaller KBOs. This is a slippery slope argument that does not apply here; if astronomical consensus changes (be it the inclusion of a smaller object such as Salacia, or the exclusion of an object such as Orcus), then we shall follow said changes. As of now, proposing that any of the smaller objects you've mentioned should be treated as dwarf planets here would possibly fall under WP:CRYSTAL or WP:FRINGE. ArkHyena (talk) 01:50, 13 June 2024 (UTC)

  proposing that any of the smaller objects you've mentioned should be treated as dwarf planets here would possibly fall under WP:CRYSTAL -- the claim that "then someone will suggest moving Salacia, then someone will suggest Varuna and Ixion" certainly is WP:CRYSTAL. The point being made, that we are kicking off a cascade of move requests by allowing the proposed moves to happen, is false per the discussion above. Renerpho (talk) 02:08, 13 June 2024 (UTC)

  Fair point! I was more concerned with any future (hypothetical) push to treat Salacia etc. as dwarf planets on Wikipedia. Barring a change in consensus and/or some major new discovery, doing so would have very little grounds to stand on and would likely fall under WP:FRINGE due to significantly departing from mainstream astronomical interpretations. Therefore, it can reasonably be expected that this "slippery slope" scenario is unlikely to materialize, and our current decisions should not be held sway to such a scenario. ArkHyena (talk) 04:47, 13 June 2024 (UTC)

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

Wrong parameter in reference

In reference #4 (Slyuta&Kreslavsky, 1990), the "postscript" parameter is used for a purpose it was never designed for (it is only to be used to control the punctuation mark, according to Template:Cite conference). As a result, a necessary space is missing before "(for Sedna Planitia)". Any ideas how to handle this better? Renerpho (talk) 11:29, 15 June 2024 (UTC)

request for additional graphic/illustration

The article states that Sedna travels outside the Heliopause. There is a graphic (https://en.wiki.x.io/wiki/Sedna_(dwarf_planet)#/media/File:Sednoid_orbits.png) of the Sednoid orbits, and a link to a graphic (https://en.wiki.x.io/wiki/Heliosphere#/media/File:PIA22835-VoyagerProgram&Heliosphere-Chart-20181210.png which is https://photojournal.jpl.nasa.gov/figures/PIA22835_fig1.png) of the Heliopause. I would appreciate it very much if someone can produce/link-to an illustration combining the Sednoid orbits with respect to the Heliopause and the Voyager spacecraft. It would answer this question: Is Sedna ahead of, or behind, or beside, the Sun as it moves around the galaxy? Dwm39tall (talk) 17:14, 26 June 2024 (UTC)

@Dwm39tall: Sedna's aphelion (near 18h27m, -14°23') is located not far from the Solar apex (18h28m, +30°0'), the direction that the Sun is traveling in. This means that most of Sedna's elongated orbit lies outside of the heliosphere, with Sedna "ahead" of the Sun most of the time, except for the few hundred years around perihelion. I guess we could try to make a chart like the one you're suggesting. I'm not sure what question it would answer? It would confirm than the claim in the article ("... sending most of its highly elongated orbit well beyond the heliopause") is true; what else? Why would it be useful to have the Voyager spacecraft in there, and is there a source that says whether the position of Sedna's orbit with respect to the Solar apex is notable? Renerpho (talk) 23:16, 27 June 2024 (UTC)

Semi-Major-Acis

According to JPL, the semi major axis of sedna is 552.1388197031947AU (https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=Sedna). It is displayed as 506.0 here. Is this a mistake or am i missing something? Sera00 (talk) 18:04, 22 December 2024 (UTC)

Motion of the Solar System's barycenter relative to the Sun

@Sera00: 506 AU refers to the barycentric, the JPL value of 552 AU to the heliocentric orbital elements; compare the reference for the semi-major axis (ref. 5).

The Sun is in a wobbly orbit around the Solar System's center of mass (its barycenter), see the image to the right; and distant objects like Sedna aren't really orbiting the Sun, but the barycenter. For distant objects, especially those that are in an eccentric orbit (like Sedna), the barycentric orbital elements are much more stable (and closer to their long-term average), and are therefore considered more useful. Renerpho (talk) 19:02, 22 December 2024 (UTC)