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Added missing "." in Mass listing on table. Abyssoft 21:08, 5 July 2006 (UTC)
From “IAU's Planet Definition” Questions & Answers Sheet: [1]
(90482) Orcus 1000±200 km [Brown, Binzel, private communication (2006)]
It may be much smaller than thought.-- JyriL talk 14:04, 16 August 2006 (UTC)
So what's up with the listed dimensions for Orcus?: "946.3+74.1-72.3 km.", it looks like it could be formatted better. I'll leave the correction for someone who knows better. HunterTruth ( talk) 16:17, 26 January 2008 (UTC)
In the intro: "The diameter of Orcus is estimated to be 761 or 807 km and the diameter of Vanth 378 or 267 km respectively, depending on their relative albedos."
In the info-box: "Dimensions 917±25 km"
In the section, "Size and magnitude": "If the albedos of both bodies are the same at 0.23 then the size of Orcus is about 917±25 km, and the size of Vanth is about 276±17 km."
There's a big inconsistency between the intro and the Size&Mag section, and given the various estimates of albedo, the ±25 km in the info-box doesn't actually show the full error-range.
Additionally, the info-box should specify what the 917km actually refers to; diameter, radius, major axis, etc, not just "Dimensions". -- PaulxSA ( talk) 06:16, 23 February 2017 (UTC)
I do not believe that we should use proposals as references. After all, if an astronomer wants to get a grant/telescope time etc. he could mention the possibility that the object is … inhabited. I feel we should keep with the usual sources. Let Mr Brown publish first. Eurocommuter 16:08, 21 August 2006 (UTC)
The discovery of a satellite for Orcus has been published in IAUC 8812, but I haven't actually seen the circular, so I have no details. RandomCritic 02:03, 25 February 2007 (UTC)
this change in the Albedo does not make sense. It is way too high' and I could not find any sources for it. I am changing back to the 0.09 value. Chagai 18:47, 26 October 2007 (UTC)
Mike Brown just named Orcus's moon. But it's not official until he clears it with the IAU. So should we start making the changes now, to make things easier, or should we wait until it's confirmed beyond doubt? Serendi pod ous 20:00, 7 April 2009 (UTC)
Oh, if anyone wants to have a look at it, I went looking and found the discovery image of Orcus + moon here in the HST archive (Aladin Java applet will load). Iridia ( talk) 03:13, 8 April 2009 (UTC)
The following paper:
{{
cite journal}}
: Unknown parameter |coauthors=
ignored (|author=
suggested) (
help); Unknown parameter |month=
ignored (
help)suggests that the ~10h periodic variability may be caused by the orbit of the satellite and hence the rotation of Orcus might be much faster. For what it's worth.— RJH ( talk) 22:58, 7 December 2010 (UTC)
During several automated bot runs the following external link was found to be unavailable. Please check if the link is in fact down and fix or remove it in that case!
-- JeffGBot ( talk) 21:45, 19 June 2011 (UTC)
The related Category:Orcus has been nominated for deletion, merging, or renaming . You are encouraged to join the discussion on the Categories for discussion page. |
To move the article without prior consensus is a complete mystery to me. The given rationale is not good enough and will cause an administrative nightmare. Guess this opens the door to endless discussions about which TNO is or is not a DP. It's crazy... -- Cheers, Rfassbind – talk 22:56, 18 September 2015 (UTC)
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On 1 April 2015, the category Category:90482 Orcus has been created and added to the article's categories. Although I don't think this category makes much sense, there might be a rationale I'm missing. Can its creator, Solomonfromfinland, or anyone else help me understand? Rfassbind – talk 23:31, 2 April 2017 (UTC)
The Kuiper belt object 90482 Orcus is named after Orcus. This was because Orcus was sometimes considered to be another name for Pluto, and also because Pluto and 90482 Orcus are both plutinos.
For the moon, see Vanth (moon).
Btw, the correct date is April 2017, not April 2015. (I'm not offended by said mistake; I just wanted to point it out politely.)-- Solomonfromfinland ( talk) 17:28, 8 April 2017 (UTC)
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https://www.youtube.com/watch?v=2rrelv96nCQ
I am not a believer in the Nibiru cataclysm, so what is in that final image? 103.38.21.38 ( talk) 05:25, 15 December 2019 (UTC)
Will there be a mission to orcus? — Preceding unsigned comment added by Zachbarbo ( talk • contribs) 19:46, 9 November 2021 (UTC)
How long will a flyby mission to Orcus will take? — Preceding unsigned comment added by Zachbarbo ( talk • contribs) 15:12, 10 November 2021 (UTC)
There is a move discussion in progress on Talk:90377 Sedna which affects this page. Please participate on that page and not in this talk page section. Thank you. — RMCD bot 20:00, 14 November 2022 (UTC)
I tagged this sentence as failed verification: Orcus had been accepted by many astronomers as a dwarf planet, though as of 2024 that consensus has changed. [2]
@ Double sharp: responded: See below - they argue that Sedna, Gonggong, Quaoar differ from "all smaller TNOs" (which would include Orcus) in ways that imply they have undergone chemical evolution while the smaller ones have not, which is the point of the DP category
I read the paper before I tagged it for failed verification, I assume you were talking about this sentence: We suggest that these three bodies have undergone internal melting and geochemical evolution similar to the larger dwarf planets and distinct from all smaller KBOs. To nitpick, the underlined part doesn't logically imply that all smaller KBOs are definitely not dwarf planets. The rest of the text more or less puts Sedna, Gonggong and Quaoar in a third group different from both larger bodies and undiscussed smaller bodies (no evidence of neither methane nor methanol).
Not being listed in a single paper specifically focusing on chemical composition of three unrelated dwarf planet candidates to me isn't enough of a development to belong right in the third sentence for Orcus. Especially since the Dwarf planet article goes on and on about how there's no consensus on which TNOs are dwarf planets (There is no clear definition of what constitutes a dwarf planet, and whether to classify an object as one is up to individual astronomers). IvicaInsomniac ( talk) 21:40, 13 March 2024 (UTC)
@ Double sharp has edited this page was well as other pages mentioning Orcus to remove any mentions of there being an established consensus among astronomers confirming Orcus's dwarf planet status. (The other pages edited by Double sharp include Solar System, Timeline of discovery of Solar System planets and their moons, Dwarf Planet, List of possible dwarf planets, and List of gravitationally rounded objects of the Solar System. Double sharp also edited Template:Solar System, but this edit was partially reverted by @ ArkHyena. Interestingly, Double sharp did not remove Orcus from the chart on Clearing the neighbourhood, but this may have just been an oversight.) This was primarily due to the release of Emory et alii's study. I think, however, it was premature to make these edits for the following reasons.
1. Orcus's estimated diameter of 910+50
−40 kilometers is larger than Sedna's 906+314
−258 kilometers. (Sedna was the smallest dwarf planet analyzed in the study.) In fact, even if we took the lowermost end of the range for Orcus, 870 kilometers, it would still be larger than the lowermost end for Sedna, 648 kilometers. Therefore, it is safe to say that Orcus is easily within the size range of the three dwarf planets mentioned by the study, (
Gònggōng,
Quaoar, and
Sedna). So, it's not accurate to classify Orcus as being one of the "smaller KBOs" alluded to by the sentence, "We suggest that these three bodies have undergone internal melting and geochemical evolution similar to the larger dwarf planets and distinct from all smaller KBOs," in the study.
2. As @ IvicaInsomniac pointed out, Orcus not being mentioned in the study does not mean the authors were implying it's not a dwarf planet. It would be like saying a study analyzing all of the planets except for Mercury must somehow be implying Mercury is not actually a planet. @ Kwamikagami has brought the point that one go even further with this to imply that possible dwarf planet candidates may also not be ruled out from not being mentioned in the study. However, unlike Orcus, those candidates do not have any consensus surrounding them, while Orcus does.
3. Even if Orcus were smaller than Sedna, the study in question, as pointed out by IvicaInsomniac, does not state that celestial bodies smaller than the three dwarf planets analyzed are not dwarf planets.
4. The argument that Orcus's density is "too close" to the borderline dividing dwarf planets from what would essentially be large, slightly rounded asteroids has been brought up by Double sharp. However, every one of the studies that analyzed density to determine dwarf planet status all ultimately determined that Orcus does indeed meet the threshold. Scientific consensus among astronomers should take precedent over our personal interpretations of the data, no matter how valid they may be. (After all, Wikipedia is about following, not leading.)
5. The argument that Salacia is more or less in the "same grey area" as Orcus when it comes to having a similar size, density, and albedo has also been brought up by Double sharp. However, unlike Orcus, no consensus was ever formed about Salacia's possible dwarf planet status, (as @ Ardenau4 pointed out, astronomers seem to currently be split on this), which is very different from Double sharp's argument that the consensus regarding Orcus's status has changed.
I propose reverting Double sharp's edits to how things to how things were before, including the other articles. (No offense to Double sharp, by the way. Sorry if I seem too harsh with this, lol.) Additionally, I propose modifying the chart on List of possible dwarf planets to change the yellow question mark for Orcus under the new study to a green checkmark with perhaps a footnote attached stating something along the lines of, "Not explicitly analyzed nor mentioned, but in the same size range of the dwarf planets evaluated." Alternatively, since, as I talked about above, the study does not state that celestial bodies smaller than the three dwarf planets it analyzed have not undergone the geochemical evolution "necessary" to be a dwarf planet, it might be better to remove that study from the chart entirely and just keep the other three. Unlike the other three studies, the study in question is simply not about determining dwarf planet status. Star VV Cephei A ( talk) 21:43, 23 May 2024 (UTC)
Double sharp's edits cause further complications.
Should the italicized sentence at the topic of the article for the Roman god Orcus be changed from saying Orcus is a "dwarf planet" to a "likely dwarf planet"? Or, perhaps a "possible dwarf planet candidate"?
Should the simple English article on Orcus be modified as well? What about the simple English dwarf planet article? What about how articles in other languages still call Orcus a dwarf planet?
And how about these three images prominently displayed in the Solar System and planet articles that show Orcus as one of the nine consensus dwarf planets?
With all due respect, I think Double sharp jumped the gun here. Star VV Cephei A ( talk) 00:56, 24 May 2024 (UTC)
I suppose I should explain myself. The main reason I made the changes in the first place was that the line we tended to use for DPs is between (1) those which nobody doubts, like Quaoar, and (2) those that might be, but aren't very clear, like Varda. All of them are discussed in places like list of possible dwarf planets, but you wouldn't use Varda (say) as an exemplar right off the bat the way you could use Quaoar. Since Orcus wasn't mentioned in the new study, and it was already kind of suspicious (its density is borderline), it seemed doubtful enough to move from the bottom of (1) to the top of (2). My logic thus is that the objects we list as the standard DP exemplars really ought to be the ones nobody actually doubts.
Also, the thing that makes Sedna, Gonggong, and Quaoar probably DPs in the new study is finding a significant abundance of light hydrocarbons on the surface: that suggests differentiation (for a continuous renewal of them), and is absent from smaller TNOs. These have not been found for Orcus, despite the fact that spectroscopic observations have been done (see 90482 Orcus#Spectra and surface): future studies may yet identify them, but the fact that they haven't been found yet suggests that the abundance might actually be intrinsically low. Kind of SYNTH though, I admit.
It's true that I made the changes before more detailed studies on Orcus came out. So arguably I jumped the gun, and I'm fine with reinstating it for now. I'll still privately bet against it, though. ;) Double sharp ( talk) 12:20, 24 May 2024 (UTC)
The result of the move request was: moved. ( non-admin closure) Safari Scribe Edits! Talk! 04:53, 22 June 2024 (UTC)
90482 Orcus → Orcus (dwarf planet), and include it in Wikipedia:Featured topics/Dwarf planets – To maintain consistency, per WP:TITLECON. The recent discussion at Talk:Sedna (dwarf planet) has established that Sedna, Gonggong and Quaoar are considered dwarf planets by the established scientific consensus, and those articles were moved accordingly. There is no qualitative difference between the situation for those objects and Orcus. Orcus was mentioned in the discussion at Sedna, but was purposefully left out (for reasons explained below) so it can be discussed here separately. Now is the time to do that.
Wikipedia does not follow the IAU's position when it comes to determining which objects are considered dwarf planets in the scientific literature. Rather, Wikipedia:Naming conventions (astronomical objects)#Dwarf planets now asks for objects to be included in Wikipedia:Featured topics/Dwarf planets before they are titled as such. The purpose of this, as explained here, is to ensure that a thorough discussion has taken place whether there is sufficient scientific consensus, thus ensuring a stable basis for what objects we consider to be dwarf planets. This is currently the case for the eight objects on the featured topic. It also appears that Orcus is the only other object that may currently qualify to be added to that list. The Orcus article itself of course treats Orcus as a dwarf planet, and has done so for quite some time.
The reason why Orcus was left out of the recent move request is that its status was unclear: Orcus had been added to that featured topic in early 2024, [3] but this was challenged in May. [4] As a good article, Orcus is technically eligible to be on that list. Its removal sparked the discussion at Talk:90482 Orcus#Dwarf planet or not, which was followed up by Talk:90482 Orcus#The Consensus Is That Orcus Is Still A Dwarf Planet. The arguments for and against a possible move have been outlined, and I point there for further details, but the arguments in favour of considering Orcus a dwarf planet are basically the same as in the move request for Sedna, Gonggong and Quaoar. While there were some opposing views (as there were in the successful move request for the other three objects), the arguments against were basically the same, too.
To maintain consistency, I believe that Orcus should therefore be included in the featured topic, and the article should be titled accordingly. Renerpho ( talk) 11:51, 14 June 2024 (UTC)
There should be a parallel (or at least subsequent) discussion-- I suggest a parallel discussion. The two questions are directly linked. I have amended the proposal accordingly, requesting not only to move the article, but also to include it in the featured topics list. Comment Just for reference, I'd like to point out that Igordebraga's removal of Orcus from the featured topics list was based on a comment by ArkHyena during its FTC in April. [5] Renerpho ( talk) 16:15, 14 June 2024 (UTC)
Orcus (dwarf planet) has been listed as one of the
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The contents of the Vanth (moon) page were merged into Orcus (dwarf planet). For the contribution history and old versions of the redirected page, please see its history; for the discussion at that location, see its talk page. (12 January 2017) |
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Discussions:
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Added missing "." in Mass listing on table. Abyssoft 21:08, 5 July 2006 (UTC)
From “IAU's Planet Definition” Questions & Answers Sheet: [1]
(90482) Orcus 1000±200 km [Brown, Binzel, private communication (2006)]
It may be much smaller than thought.-- JyriL talk 14:04, 16 August 2006 (UTC)
So what's up with the listed dimensions for Orcus?: "946.3+74.1-72.3 km.", it looks like it could be formatted better. I'll leave the correction for someone who knows better. HunterTruth ( talk) 16:17, 26 January 2008 (UTC)
In the intro: "The diameter of Orcus is estimated to be 761 or 807 km and the diameter of Vanth 378 or 267 km respectively, depending on their relative albedos."
In the info-box: "Dimensions 917±25 km"
In the section, "Size and magnitude": "If the albedos of both bodies are the same at 0.23 then the size of Orcus is about 917±25 km, and the size of Vanth is about 276±17 km."
There's a big inconsistency between the intro and the Size&Mag section, and given the various estimates of albedo, the ±25 km in the info-box doesn't actually show the full error-range.
Additionally, the info-box should specify what the 917km actually refers to; diameter, radius, major axis, etc, not just "Dimensions". -- PaulxSA ( talk) 06:16, 23 February 2017 (UTC)
I do not believe that we should use proposals as references. After all, if an astronomer wants to get a grant/telescope time etc. he could mention the possibility that the object is … inhabited. I feel we should keep with the usual sources. Let Mr Brown publish first. Eurocommuter 16:08, 21 August 2006 (UTC)
The discovery of a satellite for Orcus has been published in IAUC 8812, but I haven't actually seen the circular, so I have no details. RandomCritic 02:03, 25 February 2007 (UTC)
this change in the Albedo does not make sense. It is way too high' and I could not find any sources for it. I am changing back to the 0.09 value. Chagai 18:47, 26 October 2007 (UTC)
Mike Brown just named Orcus's moon. But it's not official until he clears it with the IAU. So should we start making the changes now, to make things easier, or should we wait until it's confirmed beyond doubt? Serendi pod ous 20:00, 7 April 2009 (UTC)
Oh, if anyone wants to have a look at it, I went looking and found the discovery image of Orcus + moon here in the HST archive (Aladin Java applet will load). Iridia ( talk) 03:13, 8 April 2009 (UTC)
The following paper:
{{
cite journal}}
: Unknown parameter |coauthors=
ignored (|author=
suggested) (
help); Unknown parameter |month=
ignored (
help)suggests that the ~10h periodic variability may be caused by the orbit of the satellite and hence the rotation of Orcus might be much faster. For what it's worth.— RJH ( talk) 22:58, 7 December 2010 (UTC)
During several automated bot runs the following external link was found to be unavailable. Please check if the link is in fact down and fix or remove it in that case!
-- JeffGBot ( talk) 21:45, 19 June 2011 (UTC)
The related Category:Orcus has been nominated for deletion, merging, or renaming . You are encouraged to join the discussion on the Categories for discussion page. |
To move the article without prior consensus is a complete mystery to me. The given rationale is not good enough and will cause an administrative nightmare. Guess this opens the door to endless discussions about which TNO is or is not a DP. It's crazy... -- Cheers, Rfassbind – talk 22:56, 18 September 2015 (UTC)
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On 1 April 2015, the category Category:90482 Orcus has been created and added to the article's categories. Although I don't think this category makes much sense, there might be a rationale I'm missing. Can its creator, Solomonfromfinland, or anyone else help me understand? Rfassbind – talk 23:31, 2 April 2017 (UTC)
The Kuiper belt object 90482 Orcus is named after Orcus. This was because Orcus was sometimes considered to be another name for Pluto, and also because Pluto and 90482 Orcus are both plutinos.
For the moon, see Vanth (moon).
Btw, the correct date is April 2017, not April 2015. (I'm not offended by said mistake; I just wanted to point it out politely.)-- Solomonfromfinland ( talk) 17:28, 8 April 2017 (UTC)
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https://www.youtube.com/watch?v=2rrelv96nCQ
I am not a believer in the Nibiru cataclysm, so what is in that final image? 103.38.21.38 ( talk) 05:25, 15 December 2019 (UTC)
Will there be a mission to orcus? — Preceding unsigned comment added by Zachbarbo ( talk • contribs) 19:46, 9 November 2021 (UTC)
How long will a flyby mission to Orcus will take? — Preceding unsigned comment added by Zachbarbo ( talk • contribs) 15:12, 10 November 2021 (UTC)
There is a move discussion in progress on Talk:90377 Sedna which affects this page. Please participate on that page and not in this talk page section. Thank you. — RMCD bot 20:00, 14 November 2022 (UTC)
I tagged this sentence as failed verification: Orcus had been accepted by many astronomers as a dwarf planet, though as of 2024 that consensus has changed. [2]
@ Double sharp: responded: See below - they argue that Sedna, Gonggong, Quaoar differ from "all smaller TNOs" (which would include Orcus) in ways that imply they have undergone chemical evolution while the smaller ones have not, which is the point of the DP category
I read the paper before I tagged it for failed verification, I assume you were talking about this sentence: We suggest that these three bodies have undergone internal melting and geochemical evolution similar to the larger dwarf planets and distinct from all smaller KBOs. To nitpick, the underlined part doesn't logically imply that all smaller KBOs are definitely not dwarf planets. The rest of the text more or less puts Sedna, Gonggong and Quaoar in a third group different from both larger bodies and undiscussed smaller bodies (no evidence of neither methane nor methanol).
Not being listed in a single paper specifically focusing on chemical composition of three unrelated dwarf planet candidates to me isn't enough of a development to belong right in the third sentence for Orcus. Especially since the Dwarf planet article goes on and on about how there's no consensus on which TNOs are dwarf planets (There is no clear definition of what constitutes a dwarf planet, and whether to classify an object as one is up to individual astronomers). IvicaInsomniac ( talk) 21:40, 13 March 2024 (UTC)
@ Double sharp has edited this page was well as other pages mentioning Orcus to remove any mentions of there being an established consensus among astronomers confirming Orcus's dwarf planet status. (The other pages edited by Double sharp include Solar System, Timeline of discovery of Solar System planets and their moons, Dwarf Planet, List of possible dwarf planets, and List of gravitationally rounded objects of the Solar System. Double sharp also edited Template:Solar System, but this edit was partially reverted by @ ArkHyena. Interestingly, Double sharp did not remove Orcus from the chart on Clearing the neighbourhood, but this may have just been an oversight.) This was primarily due to the release of Emory et alii's study. I think, however, it was premature to make these edits for the following reasons.
1. Orcus's estimated diameter of 910+50
−40 kilometers is larger than Sedna's 906+314
−258 kilometers. (Sedna was the smallest dwarf planet analyzed in the study.) In fact, even if we took the lowermost end of the range for Orcus, 870 kilometers, it would still be larger than the lowermost end for Sedna, 648 kilometers. Therefore, it is safe to say that Orcus is easily within the size range of the three dwarf planets mentioned by the study, (
Gònggōng,
Quaoar, and
Sedna). So, it's not accurate to classify Orcus as being one of the "smaller KBOs" alluded to by the sentence, "We suggest that these three bodies have undergone internal melting and geochemical evolution similar to the larger dwarf planets and distinct from all smaller KBOs," in the study.
2. As @ IvicaInsomniac pointed out, Orcus not being mentioned in the study does not mean the authors were implying it's not a dwarf planet. It would be like saying a study analyzing all of the planets except for Mercury must somehow be implying Mercury is not actually a planet. @ Kwamikagami has brought the point that one go even further with this to imply that possible dwarf planet candidates may also not be ruled out from not being mentioned in the study. However, unlike Orcus, those candidates do not have any consensus surrounding them, while Orcus does.
3. Even if Orcus were smaller than Sedna, the study in question, as pointed out by IvicaInsomniac, does not state that celestial bodies smaller than the three dwarf planets analyzed are not dwarf planets.
4. The argument that Orcus's density is "too close" to the borderline dividing dwarf planets from what would essentially be large, slightly rounded asteroids has been brought up by Double sharp. However, every one of the studies that analyzed density to determine dwarf planet status all ultimately determined that Orcus does indeed meet the threshold. Scientific consensus among astronomers should take precedent over our personal interpretations of the data, no matter how valid they may be. (After all, Wikipedia is about following, not leading.)
5. The argument that Salacia is more or less in the "same grey area" as Orcus when it comes to having a similar size, density, and albedo has also been brought up by Double sharp. However, unlike Orcus, no consensus was ever formed about Salacia's possible dwarf planet status, (as @ Ardenau4 pointed out, astronomers seem to currently be split on this), which is very different from Double sharp's argument that the consensus regarding Orcus's status has changed.
I propose reverting Double sharp's edits to how things to how things were before, including the other articles. (No offense to Double sharp, by the way. Sorry if I seem too harsh with this, lol.) Additionally, I propose modifying the chart on List of possible dwarf planets to change the yellow question mark for Orcus under the new study to a green checkmark with perhaps a footnote attached stating something along the lines of, "Not explicitly analyzed nor mentioned, but in the same size range of the dwarf planets evaluated." Alternatively, since, as I talked about above, the study does not state that celestial bodies smaller than the three dwarf planets it analyzed have not undergone the geochemical evolution "necessary" to be a dwarf planet, it might be better to remove that study from the chart entirely and just keep the other three. Unlike the other three studies, the study in question is simply not about determining dwarf planet status. Star VV Cephei A ( talk) 21:43, 23 May 2024 (UTC)
Double sharp's edits cause further complications.
Should the italicized sentence at the topic of the article for the Roman god Orcus be changed from saying Orcus is a "dwarf planet" to a "likely dwarf planet"? Or, perhaps a "possible dwarf planet candidate"?
Should the simple English article on Orcus be modified as well? What about the simple English dwarf planet article? What about how articles in other languages still call Orcus a dwarf planet?
And how about these three images prominently displayed in the Solar System and planet articles that show Orcus as one of the nine consensus dwarf planets?
With all due respect, I think Double sharp jumped the gun here. Star VV Cephei A ( talk) 00:56, 24 May 2024 (UTC)
I suppose I should explain myself. The main reason I made the changes in the first place was that the line we tended to use for DPs is between (1) those which nobody doubts, like Quaoar, and (2) those that might be, but aren't very clear, like Varda. All of them are discussed in places like list of possible dwarf planets, but you wouldn't use Varda (say) as an exemplar right off the bat the way you could use Quaoar. Since Orcus wasn't mentioned in the new study, and it was already kind of suspicious (its density is borderline), it seemed doubtful enough to move from the bottom of (1) to the top of (2). My logic thus is that the objects we list as the standard DP exemplars really ought to be the ones nobody actually doubts.
Also, the thing that makes Sedna, Gonggong, and Quaoar probably DPs in the new study is finding a significant abundance of light hydrocarbons on the surface: that suggests differentiation (for a continuous renewal of them), and is absent from smaller TNOs. These have not been found for Orcus, despite the fact that spectroscopic observations have been done (see 90482 Orcus#Spectra and surface): future studies may yet identify them, but the fact that they haven't been found yet suggests that the abundance might actually be intrinsically low. Kind of SYNTH though, I admit.
It's true that I made the changes before more detailed studies on Orcus came out. So arguably I jumped the gun, and I'm fine with reinstating it for now. I'll still privately bet against it, though. ;) Double sharp ( talk) 12:20, 24 May 2024 (UTC)
The result of the move request was: moved. ( non-admin closure) Safari Scribe Edits! Talk! 04:53, 22 June 2024 (UTC)
90482 Orcus → Orcus (dwarf planet), and include it in Wikipedia:Featured topics/Dwarf planets – To maintain consistency, per WP:TITLECON. The recent discussion at Talk:Sedna (dwarf planet) has established that Sedna, Gonggong and Quaoar are considered dwarf planets by the established scientific consensus, and those articles were moved accordingly. There is no qualitative difference between the situation for those objects and Orcus. Orcus was mentioned in the discussion at Sedna, but was purposefully left out (for reasons explained below) so it can be discussed here separately. Now is the time to do that.
Wikipedia does not follow the IAU's position when it comes to determining which objects are considered dwarf planets in the scientific literature. Rather, Wikipedia:Naming conventions (astronomical objects)#Dwarf planets now asks for objects to be included in Wikipedia:Featured topics/Dwarf planets before they are titled as such. The purpose of this, as explained here, is to ensure that a thorough discussion has taken place whether there is sufficient scientific consensus, thus ensuring a stable basis for what objects we consider to be dwarf planets. This is currently the case for the eight objects on the featured topic. It also appears that Orcus is the only other object that may currently qualify to be added to that list. The Orcus article itself of course treats Orcus as a dwarf planet, and has done so for quite some time.
The reason why Orcus was left out of the recent move request is that its status was unclear: Orcus had been added to that featured topic in early 2024, [3] but this was challenged in May. [4] As a good article, Orcus is technically eligible to be on that list. Its removal sparked the discussion at Talk:90482 Orcus#Dwarf planet or not, which was followed up by Talk:90482 Orcus#The Consensus Is That Orcus Is Still A Dwarf Planet. The arguments for and against a possible move have been outlined, and I point there for further details, but the arguments in favour of considering Orcus a dwarf planet are basically the same as in the move request for Sedna, Gonggong and Quaoar. While there were some opposing views (as there were in the successful move request for the other three objects), the arguments against were basically the same, too.
To maintain consistency, I believe that Orcus should therefore be included in the featured topic, and the article should be titled accordingly. Renerpho ( talk) 11:51, 14 June 2024 (UTC)
There should be a parallel (or at least subsequent) discussion-- I suggest a parallel discussion. The two questions are directly linked. I have amended the proposal accordingly, requesting not only to move the article, but also to include it in the featured topics list. Comment Just for reference, I'd like to point out that Igordebraga's removal of Orcus from the featured topics list was based on a comment by ArkHyena during its FTC in April. [5] Renerpho ( talk) 16:15, 14 June 2024 (UTC)