Talk:Dwarf planet/Archive 4

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Archive 1

Archive 2

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Administrative or scientific?

Under break three above, three editors opined that dwarf planet is not a "scientific" concept, but an "administrative" one. That is, a body is not a DP because it fits physical/dynamical criteria, but because the IAU says that it's a DP. I find that proposition dubious, but if true, we would need to revise quite a few articles to reflect this. Is there any consensus that this is the case? That is, is the IAU's "gatekeeper" role definitive? Or, conversely, is there any consensus that it is the IAU's published physical/dynamical definition of a DP that defines which objects are DPs? — kwami (talk) 19:42, 20 September 2011 (UTC)

Again, that isn't the point. There is no way we can use any one source, or even a plurality of sources, to determine whether or not an object is a dwarf planet. To do so is synthesis. We are not scientists and Wikipedia is not a science journal. It is not our job to make calls on scientific matters. We report. That's it. The IAU is the only organisation with the authority to make the call. So we wait for them to do so, even if they don't. Serendi ^pod ous 19:54, 20 September 2011 (UTC)

Then that is the point. That is exactly the point I was making. We cannot report what the journals say, but only what the IAU says. — kwami (talk) 20:10, 20 September 2011 (UTC)

And the IAU has not said they are dwarf planets. Serendi ^pod ous 20:31, 20 September 2011 (UTC)

As I understand IAU's function, it's not a sanctioning body, so its pronouncements have no de jure force. It's only got the power of a professional association: that is, members agree to abide by its decisions. Thus, IAU definitions aren't strictly scientific (in the way, say, Newton's laws are). It's authoritative, because astronomers agree it is, but not on its own. So, it would appear rewriting may be needed... Unless I've gotten it wrong... :( 19:49, 20 September 2011 (UTC)

I have no problem with the IAU defining the category. And lots of scientific categories are arbitrary: just look at biological taxonomy. My question is this: once the category is defined, is an object a member of that category because it fits the definition? Or is it only a member of that category if the IAU accepts that it's a member? One is scientifically decided, the other is not. — kwami (talk) 20:10, 20 September 2011 (UTC)

No, because there is no way we can say for certain that an object does fit the definition. One astronomer may say so; a hundred astronomers may say so, but there will never be absolute agreement. A line has to be drawn somewhere. For better or worse, in astronomy that line is drawn by the IAU, and the IAU has not drawn the line for these four objects. Serendi ^pod ous 20:39, 20 September 2011 (UTC)

Yes, we cannot be absolutely certain to know the TRUTH™, not about anything (which has not been a reason to just leave it to some organization to say how things work/are instead of engaging in science!!). It is why WP's inclusion criterion has to be verifiability. I suggest you study that page carefully. The statement that these are DPs is verifiable, and so far anything even just questioning this isn't. The only thing verifiable to put alongside the claim that these are DPs is that "these objects do not appear on the list maintained by the IAU".--JorisvS (talk) 20:59, 20 September 2011 (UTC)

But if we are to be true to Brown's list, we would have to say that they are nearly certainly DPs - the qualifier is important because the source deemed it necessary. --Ckatz^chat _spy 06:16, 22 September 2011 (UTC)

Don't get bogged down just by the name Brown uses for this category. He has also added a description of what being in this category means. I'll repeat it: We are confident enough in the size estimate to know that each one of these must be a dwarf planet even if predominantly rocky. To me the category is more important than the name it carries. --JorisvS (talk) 09:29, 22 September 2011 (UTC)

To suggest that the definition is not a scientific one but an administrative one is just crazy. There are observable criteria for what is a dwarf planet. An object is a DP because it satisfies these criteria, not because it is or isn't maintained on some list. And for those confused over what the IAU is: definitely not a governing body. --JorisvS (talk) 20:38, 20 September 2011 (UTC)

"The statement that these are DPs is verifiable" It is, unfortunately, not so simple. If there was agreement on which bodies were, & were not, DPs, we wouldn't be debating it. Nor, IMO, is WP the place to be settling it. Nor are we qualified to. What verifiability, in this instance, appears to amount to is battling cites, & that seems to me a bad idea. I would rather we err in favor of caution: name bodies by what they're known to be & leave the debate alone until it's a settled issue. TREKphiler ^{any time you're ready, Uhura} 22:27, 20 September 2011 (UTC)

No no no! Whether we debate it is irrelevant: Only debate in our sources counts! We have astrologers over at the astrology talk page all the time insisting that astrology is legitimate science. By your argument, "if astrology weren't legitimate science, we wouldn't be debating it", and therefore we must present it as if there were an actual scientific debate on astrology.

If you can show debate in the sources, we will need to reflect that. However, if there is no debate in the sources, then it is OR to put our debate in the article. — kwami (talk) 22:34, 20 September 2011 (UTC)

Blog are not reliable sources especially when they make controversial claims. And this blog is just a personal blog of M. Brown where he expresses his personal (often provocative) opinions. As to sources Britannica also lists only 5 dwarf planet. Ruslik_Zero 09:55, 21 September 2011 (UTC)

Wrong again. It's Britannica that's not a RS, as you'd know if you read our policy. Websites can be used if they're by a respected authority who is considered a RS when he's published. They aren't preferred, but are used when the material isn't published. And yes, Brown uses his blogs for opinion, but I hope we can all distinguish opinions from statements of fact? These are statements of fact. — kwami (talk) 23:43, 21 September 2011 (UTC)

Again, Brown has made it clear that he recognizes the IAU list as official, and has also made it clear that he published his list to shake things up with respect to the IAU. In addition, we have not addressed why this list should be treated any differently than his last one, in 2007(ish), at which time we also used the IAU list as our guide for inclusion. --Ckatz^chat _spy 06:19, 22 September 2011 (UTC)

"Only debate in our sources counts!" My point exactly. It's not settled in the sources, & we shouldn't be trying to settle it, or treat it as settled, here. Which appears to be what's happening. IMO, the only viable option is to state something on the lines of, "This is debated by astronomers" & make no assertions as to membership in categories that aren't firmly & unequivocably established. Which is to say, unless there is no debate where a given candidate belongs, leave it out. Otherwise, we're taking sides, & that is de facto POV. Not to mention divisive of the WP community, as the above discussion, IMO, clearly shows. Gentlemen, a little calm? Before we start calling for our seconds & our pistols? ;p TREKphiler ^{any time you're ready, Uhura} 06:31, 22 September 2011 (UTC)

So far, all of you have failed miserably in showing the supposed debate in the sources. If you had, we wouldn't be having most of the debate here! --JorisvS (talk) 09:11, 22 September 2011 (UTC)

Can we take a poll here, to at least see where we all stand?

A "dwarf planet" is an object that the IAU has declared to be a dwarf planet

Support. Unequivocally qualifying, therefore no debate in sources, therefore not contentious. TREKphiler ^{any time you're ready, Uhura} 06:31, 22 September 2011 (UTC)

The IAU definition is HE+Not cleared neighborhood+not a satellite, not "whatever object we place in this category". Just read the resolution! --JorisvS (talk) 09:11, 22 September 2011 (UTC)

We have read the resolution, and the subsequent press releases, and have come to the same conclusions as Brown and Tancredi. Tbayboy (talk) 12:22, 22 September 2011 (UTC)

Support. The sources indicate that that's how it has been interpretted. Tbayboy (talk) 12:22, 22 September 2011 (UTC)

A "dwarf planet" is an object that meets the IAU's definition of a dwarf planet

— kwami (talk) 23:50, 21 September 2011 (UTC)
Logically, --JorisvS (talk) 09:11, 22 September 2011 (UTC)
Support— that's how the IAU resolution defined it. --Roentgenium111 (talk) 15:13, 23 September 2011 (UTC)

So I take it Mike Brown is now God? His opinion is to be taken as holy writ above all others? Or will we have to gather together every single paper ever published on this topic before we come to a conclusion? Serendi ^pod ous 15:18, 23 September 2011 (UTC)

Who are you ranting at? My post (and indeed this whole section) is not about Brown, but about the definition of a dwarf planet. --Roentgenium111 (talk) 23:26, 3 October 2011 (UTC)

Neither of the above (please give a brief summary)

I think there's a confusion here between "what solar system bodies can be called dwarf planets" and "what solar system bodies have been categorized as dwarf planets." The first is just an informal description. The latter is a list of bodies which have been so categorized by the appropriate IAU subcommittee. This is spelled out on the IAU web site on the Web page http://www.iau.org/public/pluto/ where it says

[quote]Q: How will an official decision be reached on whether or not to call a newly discovered object a planet, dwarf planet, or a Solar System body? A: The decision on how to classify newly discovered objects will be made by a review committee within the IAU. The review process will be an evaluation, based on the best available data, of whether or not the physical properties of the object satisfy the definitions. It is likely that for many objects, several years may be required to gather sufficient data. [/quote]

and later

[quote]Q: Are there additional dwarf planet candidates currently being considered? A: Yes. Some of the largest asteroids may be candidates for dwarf planet status and some additional dwarf planet candidates beyond Neptune will soon be considered. [/quote]

Don't forget that the IAU is not an arbitrary body imposing things on astronomers, but is the organization of professional astronomers given this responsibility by their peers. Seldenball (talk) 20:01, 4 November 2011 (UTC)

RfC: What is a dwarf planet?

I've asked for WP:astronomy to weigh in, but we're not getting much input. We have a fundamental disagreement, and could use input from editors familiar with WP sourcing policy.

The IAU defined a new class of object, "dwarf planet" (here "DP"), to handle Pluto when it was demoted from planetary status. They created a physical definition of what a DP is, and also started a review process to determine whether a body fits that definition.

So, if we have RS's that a body qualifies, but the IAU hasn't weighed in, is the body a DP for our purposes? This seems to be a philosophic difference of whether science depends on evidence and sourcing, or on formal acceptance of that evidence. An analogy would be, if a new fossil is discovered, and a respected expert (perhaps the discoverer) says it's a bird, is it only "potentially" a bird, or a "bird candidate" until it appears in a definitive catalogue of fossil birds? Or can we here on WP accept it as a bird based on verifiable statements of the expert, who may have not yet formally published its classification as a bird? — kwami (talk) 13:35, 22 September 2011 (UTC)

Comment: Rather than agonizing over whether or not a particular body can be called a dwarf planet "officially", it seems simpler and more informative to be inclusive with notation. Currently, the article has several separate tables which could stand to be merged down into one, possibly two. Different row shadings, with legends, can indicate the "official"-ness of each body's classification. siafu (talk) 15:57, 22 September 2011 (UTC)

It's a good idea to merge these tables, whatever the outcome of the RfC discussion.--Roentgenium111 (talk) 16:36, 22 September 2011 (UTC)

Wikipedia evidence in other science areas suggests to go by the "experts", not the official body: e.g. we consider the chemical elements ununtrium, ununpentium et al. to be "discovered" in spite of them not being accepted yet by the relevant official body (IUPAC). (In fact, an IUPAC commission has even explicitly asserted that evidence for their respective discoveries is not yet conclusive, which the IAU has not done for the dwarf planets in question, AFAIK.) --Roentgenium111 (talk) 16:36, 22 September 2011 (UTC)

Then, again, still, I would disagree with WP policy. Discoveries are one thing; facts are another. I take a scientific discovery to be true (factual) only after it's been independently confirmed; the discoverer could be wrong on any number of things. (And I recall the famous case of the announced discovery which had failed to take account of the system noise... For which I still applaud the scientists involved for openly admitting the error.) Since I have no way of knowing the credentials of those involved, I really have to rely on the professional bodies. In this case, there is neither acceptance by that body nor confirmation, AFAICT. (I will admit ignorance of the details, so I may well be wrong on that last.) So I would oppose accepting an unconfirmed discovery (as noted above). I expect, again, to be in a minority... TREKphiler ^{any time you're ready, Uhura} 18:02, 22 September 2011 (UTC)

To be clear, is this debate about the potential inclusion of as-yet-undiscovered bodies, or about the inclusion of bodies that have been known for some time (including their physical characteristics) that just haven't yet been designated by the IAU? siafu (talk) 19:21, 22 September 2011 (UTC)

The second. It's about the status of Sedna, Quaoar, Orcus... --Roentgenium111 (talk) 20:05, 22 September 2011 (UTC)

Plus OR10. Four more. Those are the ones we have sources for. All the rest vary from "probably" to "might be". — kwami (talk) 20:56, 22 September 2011 (UTC)

In that case, the analogies seem a bit off (e.g., the fossil analogy). For bodies that have been known for quite awhile, the mass, size, and orbital elements (a, e, i, Omega, nu) are generally "known", so it seems entirely fair to include them, with some sort of note or reference on which ones have and haven't been indicated as dwarf planets by the IAU. siafu (talk) 17:50, 23 September 2011 (UTC)

The blog post of M. Brown is just a political statement of a scientist who discovered all these bodies and wants them all to be classified as dwarf planets. IAU likely has another opinion. There are currently no evidence that these bodies are in hydrostatic equilibrium and everything that Brown wrote in the blog are just speculations. The blog has not been peer reviwed and (not surprisingly) contains some serious errors. So, I can conclude that it is not a reliable source and can be used neither in this article nor in any other. Ruslik_Zero 19:00, 22 September 2011 (UTC)

That is pure speculation on your part. We follow our sources, not your theories on what may lie behind the sources.

As for it being an attempt for fame, as you imply, why wouldn't he be pushing for them to be planets, as Stern is with Pluto? But again, that's irrelevant. We have no sources that Brown exaggerates the evidence or is otherwise an unreliable source. — kwami (talk) 19:08, 22 September 2011 (UTC)

What speculations? That the diameter of Quaoar is listed as 980 km, when in fact it is 890 km? (probably typo) The latter value was published by Brown himself in 2010. Or may be the diameter of Orcus, which is listed as 950 km in the blog, while according to the article written by Brown it is 900 km. (Taking into account the latest measurements it can be as low as 800 km.) You are wrong that we follow sources. We follow reliable sources. Unfortunately this blog is not among them. Ruslik_Zero 19:32, 22 September 2011 (UTC)

Your speculation that it's "just a political statement" and therefore somehow unreliable. We accept Brown as a RS. Per our sourcing policy, it's perfectly acceptable to use informal publications by such authors. Whenever I say "sources", the "reliable" part is to be understood.

The diameters vary because the website is more up-to-date. As he said, he will revise the figures as new info comes in. (And no, it's not a "blog". He linked to it from a blog.) Now, he does not include error estimates online, which makes it less complete that formal publications. More up-to-date, less complete, plus his professional opinion as to how likely they are to be DPs. — kwami (talk) 20:53, 22 September 2011 (UTC)

So, the pros: it's from Mike Brown and it is more recent. The cons: there's no error estimates, it's not a formal publication, there's no endorsement from the IAU (the body which has made pronouncements on every official DP to date, and which Brown clearly believes maintains the official list), there's no verification from other scientists, and it's part of his desire to loosen up the IAU's procedure. Again, why exactly are we rushing to rewrite now when we did not under similar circumstances in 2007? Why is there such a problem with describing Sedna et al as "highly likely" DP candidates? --Ckatz^chat _spy 05:36, 23 September 2011 (UTC)

Yeah, that's pretty much what I think. Serendi ^pod ous 10:54, 23 September 2011 (UTC)

I'm fine with that as long as we're consistent: if we say that Eris is "highly likely" to be a DP. The only bodies for which this is actually known are Pluto and Ceres. — kwami (talk) 11:46, 23 September 2011 (UTC)

We are consistent. Eris is known to be more massive than Pluto and has the same diameter. If you have a problem with the IAU selection process I suggest you contact them and ask them to take action. -- Kheider (talk) 13:05, 23 September 2011 (UTC)

That's not the point. We don't know it's in HE, we assume it is. Of course, it's virtually certain, but "virtually certain" is not certain enough for some editors here. Our sources note that only Ceres and Pluto have been resolved well enough to observe that they are (or at least appear to be) in HE. Eris, Haumea, Makemake, Sedna, OR10 etc. are only inferred to be in HE based on those and other more-closely observed bodies. If from that we can say that Haumea "is" in HE, then we should be able to say that Sedna "is" as well. If we can only say that Sedna "may" be, then we should only say that Haumea "may" be. Unless, of course, HE is an administrative category and not a physical parameter.

Also, Eris does not have the smaller diameter. The diameters are equal to within the precision of the measurement. As for being more massive, that means it's less likely to be in HE: rocky bodies are not as plastic as ice. — kwami (talk) 13:16, 23 September 2011 (UTC)

That is the point Kwami. There are objects that are known to be dwarf planets, and objects that are assumed to be. Among those that are assumed to be, there are those the IAU has decided to class as dwarf planets and those the IAU has not. Since there is no rational way to gauge how much assumption is assumption enough, it's best to follow the IAU, as we have done since we began this project, rather than the opinion of any single astronomer. Serendi ^pod ous 13:22, 23 September 2011 (UTC)

In fact, for the same strength of the material, the denser an object the more easily it attains HE. On the other hand, the strength of rock is much larger than that of ice. --JorisvS (talk) 13:39, 23 September 2011 (UTC)

"Since there is no rational way to gauge how much assumption is assumption enough" – my god, Serendipodous, of course there is! We follow our sources. Why is that seemingly impossible for you to understand? Our sources decide, not us!

We would leave it to the IAU, if the IAU were a source, but they aren't. They haven't addressed the issue at all. If and when they do, then we will use them as a source. — kwami (talk) 13:49, 23 September 2011 (UTC)

You haven't cited sources. You have cited a source. That's it. What you ask for in response is impossible to find, as no scientific paper worth its salt would unequivocally say that these four objects are not dwarf planets. As for the IAU, the fact that they have chosen not to rule on this IS their position. Until they rule one way or the other, that is all we have. Anything else is just "he said/he said". Serendi ^pod ous 14:35, 23 September 2011 (UTC)

Every estimate for Eris shows it to be 2300 to 3000km in diameter. (Yes, the ~3000km estimates were too high) But we know Eris is only somewhat more dense than Pluto and that rocky bodies 900km in diameter are round. Eris is obviously a well measured dwarf planet, claiming otherwise is ridiculous. -- Kheider (talk) 13:46, 23 September 2011 (UTC)

We have sources that Ceres and Pluto are known to be round. Perhaps you have a source that Eris is known to be round, I haven't seen one. But you're saying that it's "obvious". That's OR. We follow our sources, we don't do our own research here. — kwami (talk) 13:49, 23 September 2011 (UTC)

"This now means that the family of dwarf planets in the Solar System is up to five. They are now Ceres, Pluto, Haumea, Eris and Makemake." Tbayboy (talk) 16:57, 23 September 2011 (UTC)

Serendipodous, of course no-one is going to say that they can't be DPs. But we could easily have a source that says we can't be sure. Hold on, Brown: your conclusion is not supported by the evidence. Or: a magnitude of 1 is certain, but anything above that is not, so it's a legitimate cut-off point. Do you have such a source? Until you do, we have two sources saying they're DPs, and no sources to the contrary.

As for leaving things to the IAU, I disagree fundamentally. You're turning science into a bureaucratic process rather than a scientific one. Hypothetically, the IAU becomes so sclerotic that they never address the issue again. We send a probe to Sedna and find that it's unequivocally in HE. According to you, it's still not a DP because the IAU hasn't ruled on it. — kwami (talk) 05:35, 25 September 2011 (UTC)

When people are not sure they remain silent. And contrary to your assertion any classification work is a bureaucratic process. Success of any classification depends upon its acceptances by a scientific community. This has nothing to do with truth or scientific soundness of it. Classification can be rejected by the community by purely irrational reasons. So, you can call any object dwarf planet only if there is a consensus in the scientific community that they are dwarf planets. IAU is simply an organization that speaks on behave of the scientific community and its position reflects the existing consensus. If you look into published journal articles, the five official dwarf planets are frequently called as such while nobody has called Quaoar a dwarf planet, even Brown himself. There is no evidence that this is going to change because Brown has made a political statement. Quaoar will become a dwarf planet when either IAU declares that it is or if it is routinely called a dwarf planet in peer reviewed sources. Ruslik_Zero 10:51, 25 September 2011 (UTC)

That is of course completely false. When people don't know, they commonly say 'we don't know'. You comments illustrate a profound ignorance of science: "Quaoar will become a dwarf planet when either IAU declares that it is or if it is routinely called a dwarf planet in peer reviewed sources." No, Quaoar is a DP or is not a DP depending on whether it fits the def of DP. The only question is on whether we can establish that. You sound like a legal system which takes 'innocent until proven guilty' literally: That if you murder someone, you didn't actually commit the crime unless found guilty; if you are never caught, then you never committed the crime. There is such thing as reality, and we use sources to establish what our understanding of that reality is. — kwami (talk) 19:18, 25 September 2011 (UTC)

Since you are now resorting to personal attacks in order to continue you dishonest POV pushing, I am not going to participate further in any discussions with you. Ruslik_Zero 19:24, 26 September 2011 (UTC)

Include even if not IAU - If a WP:Reliable source describes a body as a "dwarf planet" then it should be in this article, even if it has not passed the IAU litmus test. The reason is that it is the encyclopedic thing to do: the article should contain a comprehensive summary of all material on the DP topic: it should not use the IAU litmus test as a filter to hide potentially useful information from readers. If the astronomy community views the IAU as the gold standard, then the best approach is to identifying these non-IAU bodies as "not yet identified as DP by IAU". That designation in the article would be an objective thing to do, and still convey good info to the readers. Thus the article could potentially include two lists: DPs that are IAU approved, and those that are not. If a fringe source claims a body is a DP, but the mainstream does not, then WP:Fringe comes into play, and that should be omitted from the article, or else mentioned only in passing and clearly marked as fringe. --Noleander (talk) 19:39, 26 September 2011 (UTC)
- To me it is acceptable to include information about whether an object is a dwarf planet or not, as long as you do not misrepresent the opinions of the astronomers and do not engage in WP:OR. If a particular astronomer has proposed an object as a candidate dwarf planet, then the article should state as much and not leave out any of the essential details. But until a consensus is attained at the IAU, or if there is widespread consensus in the international scientific community (which I understand is essentially the same thing), the article should not be definitively stating the object is a dwarf planet. There's no need to try to get ahead of the scientific community on this; Wikipedia is already under enough negative opinion. Regards, RJH (talk) 16:33, 27 September 2011 (UTC)

Agreed about not misrepresenting our sources and no OR, that's basic. To that end I had proposed saying something like "xxx is a TNO ... . Given current certainties, it must be a dwarf planet (even if predominantly rocky),{refs Brown+Tancredi&Favre} though it has not been included in the list maintained by the IAU.{ref IAU list}". This is what the sources have told us so far, I have not seen any source voicing any doubt over such certainties. As I responded to you above, it's not about candidates. --JorisvS (talk) 16:54, 27 September 2011 (UTC)

Currently the articles about Orcus, Quaoar, Sedna and 2007OR10 state that "they are thought by Michael Brown to be certainly dwarf planets". I think it is the most precise and actually the best statement in present circumstances. Ruslik_Zero 18:32, 27 September 2011 (UTC)

Then I must ask the question: Have you taken a look at Tancredi&Favre? Links to the article are scattered in various locations around here already. --JorisvS (talk) 18:43, 27 September 2011 (UTC)

I agree with Ruslik, we have been calling Orcus, Quaoar, Sedna and 2007 OR10 "strong" candidates since 2006 (2009 for OR10). We should not rush to call them outright DPs when even Mike Brown is leaving himself wiggle room with "near certainty". All four of these candidates are estimated to be smaller than the IAU dwarfs, and we still do not have true knowledge of the mass of Sedna or OR10 since they do not have known moons. -- Kheider (talk) 19:03, 27 September 2011 (UTC)

So, Kheider, from your response I can only conclude you haven't. Ruslik, what about you? --JorisvS (talk) 19:11, 27 September 2011 (UTC)

I read their paper ~2 years ago. But sadly the main paper is not available to the public, just this brief. Never-the-less, even Mike Brown claims only "near certainty". Wikipedia should not give them the same weight as the larger 4 trans-Neptunian IAU dwarfs. -- Kheider (talk) 20:10, 27 September 2011 (UTC)

This is relatively old paper. Some assumptions the authors used are known to be wrong. Their classification is based on photometric observations. However it is known now that Orcus is viewed pole on. Not surprisingly it has zero photometric variability. So, it is dangerous to base classification on photometry only. Quaoar was not known to be an iron rich rocky object and they did not make any estimates of the critical size for such composition. Ruslik_Zero 18:51, 28 September 2011 (UTC)

But that's also true for Eris, Haumea, and Makemake. He uses the same wording for all: "near certainty" and also "must be even if rocky". And we have other sources that only Ceres and Pluto are observed to be in HE. Our articles currently reflect the bureaucratic delay at the IAU rather than our knowledge of these objects. That's just not encyclopedic. — kwami (talk) 23:31, 27 September 2011 (UTC)

But to the best of our knowledge Eris, Haumea, and Makemake are all larger than Orcus, Quaoar, Sedna and 2007OR10. -- Kheider (talk) 01:24, 28 September 2011 (UTC)

True. But HE is a point, not a scale. (At least not for our purposes.) For classification, it doesn't matter how much over the HE limit a body is. In Brown's opinion, and we have no source to the contrary, all nine bodies "must" be in HE even if rocky. I can certainly see color-coding the table in this article according to direct observation, IAU acceptance, or mathematical modeling, as a reader suggested above, and noting in the ledes of the DP articles whether or not the IAU has formally accepted them as such, but the basic point is still WP:SOURCE: we reflect what our sources say. And our sources say 9 objects are DPs beyond a reasonable doubt. — kwami (talk) 01:42, 28 September 2011 (UTC)

Comment I'm responding to the RfC, and have no previous involvement with the article. This thread does seem rather confused, so I hope I'm not posting at the wrong point within it. Anyway, it seems to me that, if we have genuinely reliable sources stating that an object meets the criteria to be a dwarf planet, then it is acceptable to list it as such, with a note to the effect that this has yet to be confirmed by the IAU. The only reasonable counterargument I can see to that would be if the IAU were the only possible reliable source for whether or not an object meets the criteria - which seems to me somewhat unlikely. Certainly, if the IAU has not made a ruling, we should mention that it hasn't, but beyond that, surely the only question is whether or not the source is truly reliable? Which, if I'm understanding this correctly, is beyond the scope of the RfC as stated - it certainly isn't something I feel competent to judge on myself, not being highly experienced with the astronomical literature. Anaxial (talk) 19:04, 11 October 2011 (UTC)

Comment After reading this thread, it is clear to me definitively labeling certain celestial objects as Dwarf planets is sufficiently contentious to require a balanced presentation of opposing views. In such case, Wikipedia should not endeavor to take a position one way or the other. Instead we should simply state "So an so calls such and such a Dwarf planet in some reliable source. (with a reference) This is contradicted by so and so who instead states such and such is not recognized as a dwarf planet, because of some factor." We present the facts and let the reader decide, as always. My76Strat (talk) 05:18, 22 October 2011 (UTC)

There is just one tiny problem with that: The lenghty discussions here have so far not produced any RS with which we could properly source a "This is contradicted by ..." part. If they had, they would have already ended long ago. --JorisvS (talk) 09:39, 22 October 2011 (UTC)

1999 TC36 probable dp?

Mike Brown calls 1999 TC36 a probable dwarf planet? Hilarious! It is a triple-component system. With a diameter of ~285km, TC36 is at best "possibly" a dp as are the centaurs 2060 Chiron and 10199 Chariklo. How many more probable dps will turnout to be unresolved binaries? Some of them might even be contact binaries! -- Kheider (talk) 14:38, 23 September 2011 (UTC)

"Probably: All icy satellite larger than 400 km are round, so we expect these objects to be round if the size estimate is correct." Obviously, the size estimates will be incorrect of those that turn out to be binaries. On the other hand, according to Tancredi&Favre (link above under "arbitrary break 3"), 1999 TC36's light curve is quite flat... (maybe whence the "(measured)" in Brown's list?) --JorisvS (talk) 17:47, 23 September 2011 (UTC)

1999 TC36 component A₁=286 ⁺⁴⁵
₋₃₈ km so it is only a "possibly" that it is an icy dwarf planet. 415km is the effective system diameter. As a result of the example set by TC36, any object estimated to be less than 800km in diameter should not be auto-upgraded by Wikipedia. -- Kheider (talk) 18:11, 23 September 2011 (UTC)

Wow, "auto-upgraded by Wikipedia"?? We were only talking about calling those things dwarf planets which the sources we have say must be dwarf planets (all far larger than this 800 km I might add). --JorisvS (talk) 19:54, 25 September 2011 (UTC)

No, not everything on Mike's "near certainty" list is "far larger than this 800 km". You are talking about how Wikipedia defines the lower limit for listing something as a dwarf planet. This is not something that Wikipedia should define. A recent estimate in 2010 shows Orcus is 850 ± 90 km in diameter. Orcus could easily be less than 800km and should not be treated on Wikipedia as an auto-dp based on Mike Brown's website that is automatically updated (with less than peer-reviewed data). -- Kheider (talk) 20:39, 25 September 2011 (UTC)

Kheider, even if more TNO's turned out to be yet-unknown binary systems (which can be excluded for Orcus et al. because they have already been resolved by the Hubble Space Telescope into a single small disc), two objects smaller than 400 km can only add up to a total "effective diameter" (as calculated from the apparent magnitude) of √2 × 400 km ≈ 566 km, not 800 km. (You need four 400km bodies to get the same amount of reflected light as for an 800 km body, not only two!) So every TNO above 566 km would still be a (double) dwarf planet even if it turned out to be a binary.--Roentgenium111 (talk) 21:11, 25 September 2011 (UTC)

For unlikely nearly-equal-sized trinaries (but with different masses), "√3 × 400 km ≈ 692 km". So I still think we should be careful making Wikipedia declarations using a personal website for objects estimated to be below ~800km. (I do agree that Orcus is a well studied binary plutino that is icy, and I do not see how it would not be a dwarf planet.) But I am still concerned with Wikipedia making dp-declarations based on a personal website. What harm is there in letting professional astronomers reply to Mike's declarations? There is no need for Wikipedia to try leading in this matter. -- Kheider (talk) 22:57, 25 September 2011 (UTC)

Then why don't you base it on the light-curve data of Tancredi and Favre? (Which are the dwarfs in the Solar System? or the short version for those who can't access the full-length version) --JorisvS (talk) 23:42, 25 September 2011 (UTC)

This statement is false because Proteus is not round. I would say that this political declaration is rather sloppy work from the scientific point of view. At least I was disappointed when read it. Ruslik_Zero 12:54, 24 September 2011 (UTC)

Proteus is not (known to be) an icy moon (i.e. primarily composed of water ice), so Brown's sentence IS correct as far as I can see. And I don't see how the small difference between 400km and "larger than Proteus"' 420 km would make any real difference for the "political declaration" you assume Brown to have made. --Roentgenium111 (talk) 20:54, 25 September 2011 (UTC)

Vast majority of TNOs are not known to be icy too. So what? Why does Brown claim that because Mimas is (almost) round all TNOs larger than it should be round as well? May be they are all rocky? Ruslik_Zero 18:57, 28 September 2011 (UTC)

He doesn't claim that, he only (implicitly) says they're probably icy (and therefore probably round). That's why he uses the "nearly certain" category only for objects large enough that they would be round even if they should be rocky, i.e. above 800 km. --Roentgenium111 (talk) 19:53, 28 September 2011 (UTC)

In this case Proteus is also probably icy and not round, which means that (icy) TNOs of comparable size may be not round too. Ruslik_Zero 17:37, 1 October 2011 (UTC)

Why should Proteus be "probably icy"? Since Neptune formed much closer to the Sun than where it currently is, it can easily have carried Proteus along from there, where rocky objects are the norm, whereas the TNOs formed where they still are, essentially. --Roentgenium111 (talk) 23:11, 3 October 2011 (UTC)

Correction. Neptune likely formed between Jupiter and Saturn, so the moons of Neptune should be icy. -- Kheider (talk) 00:28, 4 October 2011 (UTC)

Are you sure that rocky bodies cannot form at that distance? E.g. Saturn's moon Phoebe (moon) is known to be 50 % rocky (and its article states that it is believed to be a captured centaur, i.e. it originated outside of Jupiter). And Proteus' density means that it must contain at least significant amounts of rocky material. --Roentgenium111 (talk) 13:03, 4 October 2011 (UTC)

There is also a binary in there which clearly does not qualify. This is, of course, why we disprefer self-published material. But when the author is reputable, we do allow it as a RS if the material is not otherwise available. — kwami (talk) 05:40, 25 September 2011 (UTC)

You can treat a source as a reliable when it is convenient for you and as not reliable when it is convenient. A source is either reliable or not reliable: this black and white. Anything also is POV pushing. If this source is regarded as reliable than the article should state that 1999 TC36 is a likely dwarf planet based on the assertion Brown made, which will be silly. Ruslik_Zero 10:35, 25 September 2011 (UTC)

Oh, come on. Do you actually believe any of the words you write? We go off all of our sources. We don't pick and choose as you want to do. We bring all sources that address the issue and summarize their claims. — kwami (talk) 19:18, 25 September 2011 (UTC)

It seems to me that any source that defines an object as likely or probably is admitting their own uncertainty. Wikipedia is not here to echo the uncertainty of another, let alone validate it with a label. In such an example, our neutrality policy would only allow us to expound the uncertainty, factually stating that more information is necessary. I only see three possibilities, it either is a DP, and we have data to prove it fits the definition, or it is not a DP and we have data to prove it fails some criteria, or it is not scientifically known and more research is necessary. It should not be too hard to source a body into one of those three categories. IMO -- My76Strat (talk) 19:31, 22 October 2011 (UTC)

Repeated changes to DP articles while RfC is in progress

I'd appreciate some assistance - and/or feedback - with respect to others asking Kwamikagami to please stop changing the text on the DP and related articles while this RfC is under way. Kwami insists on repeatedly editing pages to reflect his perspective on the matter even when it has been reverted by multiple editors, and I'm finding it frustrating to have to continually restore the pre-existing versions when he does. (In case anyone was thinking of suggesting AN/I or 3RR, I'd like to add that I'd prefer to find a way to resolve this locally before going to those forums.) --Ckatz^chat _spy 18:20, 27 September 2011 (UTC)

If the editing behavior is indeed WP:DISRUPT, we might want to ask the editor to take a cool-down break and let the discussion come to a balanced consensus before making more reverts. Regards, RJH (talk) 19:46, 27 September 2011 (UTC)

I've had to tag the section with the DP tables as disputed because Kwami is repeatedly rewriting it to suit his perspective, even while the RfC is under way. I've also had to self-revert - unfortunately leaving the article with Kwami's material - as this is becoming ridiculous. --Ckatz^chat _spy 01:41, 28 September 2011 (UTC)

I'd also appreciate some input with regard to the content. There is clearly disagreement as to the way in which we should present the material, and the active discussion is addressing that matter. However, Kwami has repeatedly rewritten and reverted the material to present his perspective, despite objections from several other editors. I'd like to presume that there is consensus to revert his material to follow the convention we have used for the past five years, with the implicit understanding that this does not prejudice the outcome of this discussion. Thoughts? --Ckatz^chat _spy 20:37, 29 September 2011 (UTC)

We follow our sources. We have sources now we didn't have five years ago. Science doesn't stand still. If you want to include your perspective, you need to provide sources that support it. I really don't understand what's so difficult about that concept. — kwami (talk) 05:48, 30 September 2011 (UTC)

You are once again missing the point. You proposed a different way of presenting the material, one which is under active discussion here. However, you are repeatedly reinserting your material before the discussion has concluded, and despite opposition to your changes. --Ckatz^chat _spy 07:21, 30 September 2011 (UTC)

I support reversion in such a case and would revert if necessary even I more-or-less agreed with the addition. The reversion should be, as far as practicable, to the status quo ante, not to somebody else's preferred change. Anybody edit warring to include a particular point of view, particularly while discussion is taking place, is being disruptive and should be discouraged as necessary. In this case, the moral high ground of "that is what the sources say" is far too simplistic a justification for a change as the disagreement is about what the sources are in fact saying and how to express that. --Mirokado (talk) 12:06, 30 September 2011 (UTC)

Sure, if we actually had competing sources. But Ckatz hasn't produced anything. — kwami (talk) 12:10, 30 September 2011 (UTC)

The competing sources have been shown. You just ignore them. Tbayboy (talk) 12:21, 30 September 2011 (UTC)

I haven't seen them either. --JorisvS (talk) 12:35, 30 September 2011 (UTC)

They're shown above. Some of them several times. Tbayboy (talk) 12:51, 30 September 2011 (UTC)

I've gone through the articles linked above. I can't find it, aside from a few articles refraining from calling them DPs. Since I might have overlooked something, could you point me the passages you're referring to? --JorisvS (talk) 13:37, 30 September 2011 (UTC)

Okay, I'll put up a new section tonight (EST) with the sources collected. Then you can pick it apart :-) Tbayboy (talk) 14:00, 30 September 2011 (UTC)

The consensus is clear: it's not Wikipedia's job to categorise objects into DP/not-DP. We err on the side of caution: we do not demand our presents early. The IAU is the obvious arbitrating source. Rothorpe (talk) 13:08, 30 September 2011 (UTC)

What consensus? --JorisvS (talk) 13:37, 30 September 2011 (UTC)

Widespread, general agreement (see Wiktionary), everyone but you & Kwami. Rothorpe (talk) 15:00, 30 September 2011 (UTC)

Orcus, Quaoar, Sedna, and 2007OR10 (smaller) should not be treated as on equal footing to Eris, Haumea, and Makemake (larger). -- Kheider (talk) 15:11, 30 September 2011 (UTC)

Rothorpe, I don't understand what you mean by "see Wiktionary". According to Wiktionary, these four are dwarf planets. And of course it's not our job to do this. That's why we follow our sources. Why is that so difficult for people to understand? We follow our sources. If you can provide contrary sources, please do so.

Kheider, we should of course note that the IAU has not recognized these four. But by their own definition, that's not required for them to be DPs. We follow our sources. — kwami (talk) 00:37, 1 October 2011 (UTC)

I was responding to 'What consensus?' and referring to Wiktionary's definition thereof. Also according to Wiktionary, Sedna is merely a 'trans-Neptunian planetoid', there is no entry for Orcus or Quaoar and the 'dwarf planet' entry just lists the uncontroversial five. Rothorpe (talk) 01:35, 1 October 2011 (UTC)

You're using Wiktionary as a source? Really? When their source is us? How about Webster's Quotations? They use WP as a source too. Tell you what: I'll make an assertion in some obscure WP article that Sedna is a full planet, wait till Webster's Quotations picks up on it, and then use that as proof that we should change the Sedna article to match. — kwami (talk) 03:44, 1 October 2011 (UTC)

You said (00:37): "According to Wiktionary, these four are dwarf planets". But it does not say that. So now you attack it. Rothorpe (talk) 16:13, 1 October 2011 (UTC)

Note Per the above discussion, there appears to be consensus to maintain the existing IAU-based structure of the article while this RfC is under way. Accordingly, I have reverted Kwamikagami's changes that modified the list of DPs to incorporate the four other objects. The tables now present the IAU 5 as dwarf planets and the other four as "nearly certain". Kwami, per previous requests, please allow the discussions to continue until the matter is resolved. --Ckatz^chat _spy 04:22, 1 October 2011 (UTC)

You've also modified it to imply that the IAU three are known DPs when they're not. I think it's silly to break up the table when there are much more legible ways to go about this, but if we're going to break it up, we should distinguish between known and suspected DPs. — kwami (talk) 06:08, 1 October 2011 (UTC)

Suggestion List the DPs and prospective DPs in a table with a column 'Recognised by IAU'. There is no need for us to make any decisions, we can just state the facts. Martin Hogbin (talk) 14:30, 1 October 2011 (UTC)

I would support that. In fact, that's just what I've done: different colors for different levels of acceptance. — kwami (talk) 00:01, 3 October 2011 (UTC)