This is the
talk page for discussing improvements to the
90377 Sedna article. This is not a forum for general discussion of the article's subject. |
Article policies
|
Find sources: Google ( books · news · scholar · free images · WP refs) · FENS · JSTOR · TWL |
Archives: 1, 2, 3 |
90377 Sedna 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. | ||||||||||||||||||||||||||||||||||
This article appeared on Wikipedia's Main Page as Today's featured article on November 14, 2010, and on November 14, 2023. | ||||||||||||||||||||||||||||||||||
|
This
level-5 vital article is rated FA-class on Wikipedia's
content assessment scale. It is of interest to the following WikiProjects: | ||||||||||||||||||||||||
|
Daily pageviews of this article
A graph should have been displayed here but
graphs are temporarily disabled. Until they are enabled again, visit the interactive graph at
pageviews.wmcloud.org |
On 14 November 2022, it was proposed that this article be moved to Sedna (dwarf planet). The result of the discussion was no consensus. |
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)Sowff
Sowff (
talk) 02:14, 2 April 2022 (UTC)
[...] 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
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)
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)
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)
– 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)
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.
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.
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)
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)
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)
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)
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)
[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 pod ous 12:01, 28 November 2022 (UTC)
For goodness' sake. The sources in the article say:
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.
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.
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.
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)
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)
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)
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.
This is the
talk page for discussing improvements to the
90377 Sedna article. This is not a forum for general discussion of the article's subject. |
Article policies
|
Find sources: Google ( books · news · scholar · free images · WP refs) · FENS · JSTOR · TWL |
Archives: 1, 2, 3 |
90377 Sedna 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. | ||||||||||||||||||||||||||||||||||
This article appeared on Wikipedia's Main Page as Today's featured article on November 14, 2010, and on November 14, 2023. | ||||||||||||||||||||||||||||||||||
|
This
level-5 vital article is rated FA-class on Wikipedia's
content assessment scale. It is of interest to the following WikiProjects: | ||||||||||||||||||||||||
|
Daily pageviews of this article
A graph should have been displayed here but
graphs are temporarily disabled. Until they are enabled again, visit the interactive graph at
pageviews.wmcloud.org |
On 14 November 2022, it was proposed that this article be moved to Sedna (dwarf planet). The result of the discussion was no consensus. |
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)Sowff
Sowff (
talk) 02:14, 2 April 2022 (UTC)
[...] 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
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)
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)
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)
– 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)
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.
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.
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)
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)
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)
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)
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)
[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 pod ous 12:01, 28 November 2022 (UTC)
For goodness' sake. The sources in the article say:
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.
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.
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.
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)
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)
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)
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.