Talk:90377 Sedna

message: 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.
https://www.youtube.com/watch?v=3P6ROYpCha8&t=5s/
https://www.iau.org/public/themes/pluto/
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)
replies: text: 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)
replies: text: 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: "" Renerpho (talk) 03:13, 3 April 2022 (UTC)
thread_title:  Sedna is not a dwarf planet according to the IAU 

message: 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)
replies: text: 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)
replies: text:  The article status is 'kept' as of 4 February 2023. Praemonitus (talk) 18:14, 29 September 2023 (UTC)
thread_title:  [[90377_Sedna#Classification|Classification]] section needs update 

message: 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  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)
replies: text: Sounds reasonable. It could also be a "Later observations" subsection of "History". XOR'easter (talk) 16:55, 5 May 2022 (UTC)
replies: text: 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)
thread_title:  No "observations" section? 

message: *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)
replies: text: 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)
replies: text: 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)

text:  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)
replies: text: 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)
thread_title: Survey