Featured articleSedna (dwarf planet) is a featured article; it (or a previous version of it) has been identified as one of the best articles produced by the Wikipedia community. Even so, if you can update or improve it, please do so.
Featured topic starSedna (dwarf planet) is part of the Dwarf planets series, a featured topic. This is identified as among the best series of articles produced by the Wikipedia community. If you can update or improve it, please do so.
Main Page trophyThis article appeared on Wikipedia's Main Page as Today's featured article on November 14, 2010, and on November 14, 2023.
In the newsOn this day... Article milestones
DateProcessResult
September 18, 2006Good article nomineeListed
April 16, 2007Featured topic candidateNot promoted
April 19, 2009Good article reassessmentKept
July 18, 2010Peer reviewReviewed
August 18, 2010Featured article candidatePromoted
February 4, 2023Featured article reviewKept
April 21, 2024Featured topic candidatePromoted
In the news A news item involving this article was featured on Wikipedia's Main Page in the "In the news" column on March 15, 2004.
On this day... Facts from this article were featured on Wikipedia's Main Page in the "On this day..." column on November 14, 2007, November 14, 2008, November 14, 2009, November 14, 2012, November 14, 2013, November 14, 2015, November 14, 2016, November 14, 2017, November 14, 2019, and November 14, 2022.
Current status: Featured article

Sedna is not a dwarf planet according to the IAU[edit]

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.

[1]

[2]

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)[reply]

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)[reply]
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)[reply]

References

  1. ^ https://www.youtube.com/watch?v=3P6ROYpCha8&t=5s/
  2. ^ https://www.iau.org/public/themes/pluto/

Classification section needs update[edit]

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)[reply]

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

No "observations" section?[edit]

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)[reply]

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

Requested move 14 November 2022[edit]

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)[reply]

– 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)[reply]

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)[reply]

Survey[edit]

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)[reply]
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)[reply]
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)[reply]
@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)[reply]
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)[reply]

Discussion[edit]

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)[reply]
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)[reply]
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[edit]

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)[reply]

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

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)[reply]

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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]

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)[reply]

@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)[reply]
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)[reply]
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)[reply]
Kwamikagami has just made some further improvements that I'm happy with. Double sharp (talk) 21:54, 23 November 2022 (UTC)[reply]
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)[reply]
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)[reply]
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)[reply]
I think he's refering to 50000 Quaoar, 90482 Orcus and 225088 Gonggong, all of which have the same issue. Serendipodous 10:50, 28 November 2022 (UTC)[reply]
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)[reply]

[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. Serendipodous 12:01, 28 November 2022 (UTC)[reply]

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

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)[reply]

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)[reply]
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)[reply]
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)[reply]

Longest orbital period?[edit]

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)[reply]

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

Requested move 6 June 2024[edit]

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)[reply]

– 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)[reply]

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)[reply]
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)[reply]
Support per @Amakuru Killuminator (talk) 00:22, 7 June 2024 (UTC)[reply]
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)[reply]
    @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)[reply]
    @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)[reply]
    @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)[reply]
    @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)[reply]
    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)[reply]
    @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)[reply]
    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)[reply]
InTheAstronomy32 (talk) 18:25, 7 June 2024 (UTC)[reply]
@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)[reply]
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)[reply]
No problem here either. AstroChara (talk) 01:56, 8 June 2024 (UTC)[reply]
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[edit]

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)[reply]

Categories