Talk:Eris (dwarf planet)

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Archive

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2005
April-July 2006
July-August 2006
Discordian archive
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Contents

[edit] Discordian reference

I think that the Discordian's role in naming the planet should be metioned in the article —Preceding unsigned comment added by 64.175.42.156 (talk • contribs)

They had no role in naming it. It just so happens that the goddess Mike Brown chose to name it after is also one adopted by the Discordians. Serendipodous 09:07, 28 November 2007 (UTC)

[edit] Clarification

I don't understand why Eris was ruled to be a dwarf planet instead of the next planet. After all, it's bigger than Pluto, and its moon, Dysnomia, is nowhere near as big in comparison to it as Charon is to Pluto. Can someone explain why it's a dwarf planet?

The short answer (if there is such a thing with Pluto) is because Eris is smaller than the Planet astronomers thought Pluto was back in the 1930's through the 1950's. Back when Pluto was discovered they thought it was larger than the Earth and perhaps as large as Neptune. (Pluto from a 1959 Book) -- Kheider (talk) 02:08, 24 December 2007 (UTC)

That isn't strictly true; Pluto was demoted because it was part of a population of similar objects. For a cute (if rather condescending) summation of the issue see Why Isn't Pluto a Planet Any More? Serendipodous 05:55, 24 December 2007 (UTC)

[edit] Whats Eris sign?

SO FAR I SEEN A SIGN FOR SUN, MERCURY, VENUS, EARTH, MARS, JUPITER, SATURN, URANUS, NEPTUNE, PLUTO, AND CERUS. WHATS ERIS SIGN? —Preceding unsigned comment added by 24.188.17.249 (talk) 06:04, 15 January 2008 (UTC)

Eris doesn't have one. Nowadays astronomers don't really need symbols to represent planetary objects anymore, though astrologers are naturally interested. Serendipodous 10:53, 15 January 2008 (UTC)

[edit] protection

can we remove the protection now? Kingturtle (talk) 17:51, 4 April 2008 (UTC)

We can, but all of the (dwarf) planet articles attract constant vandalism. There are very few anonymous edits other than vandalism; also, all these articles are FA, which means that they no longer need much input. There's also the problem of having the "best" of wikipedia being full of nonsense. Even if it's for a few minutes, that's the only version some readers will see. Why keep a star on an article that starts off with "Fred sucks"? kwami (talk) 20:36, 4 April 2008 (UTC)

[edit] Eris Aphelion and Perihelion dates?

"Eris came to perihelion between 1698[22]-1699,[23] aphelion around 1977,[23] and will return to perihelion around 2256[23] to 2258.[24]"

I checked these sources and I don't find these dates quoted anywhere. Where did they come up with these dates from? Please tell me. Thank You. Maldek (talk) 07:41, 16 May 2008 (UTC)

NASA's ephemeris generator is set to default on Mars, but can be set to Eris, and the time span can be set to any period desired. Ref 24 does mention that perihelion passage will take place in 2258. Serendipodous 07:49, 16 May 2008 (UTC)

According to (Ref 22: Lowell Orbit Fit): "Time of Perihelion: 2341442.0799". Using a Julian Date Converter, you get the year 1698. -- Kheider (talk) 20:45, 16 May 2008 (UTC)

Since Horizons is the only one that lists an Aphelion (furthest from Sun) I will show how to re-generate that result.

  • 1) Go to Horizons (This link should force Eris as the Target Body.)
  • 2) Make sure Ephemeris Type is set to: OBSERVER (default)
  • 3) Set Observer Location to @sun (for center of the sun)
  • 4) Set Time Span for 1977-01-01 to 1978-01-01
  • 5) Click Generate Table
  • 6) Look for a deldot (change of direction) of 0.0000. Currently Aphelion shows as 1977-Mar-15.
  • As an added bonus look at the top box. It shows "TP= 2256-Feb-28.7024295" (Perihelion) -- Kheider (talk) 10:58, 17 May 2008 (UTC)

[edit] Eh?

so, how many planets r there anyway? —Preceding unsigned comment added by Balkall (talk • contribs)

Eight. At the moment.Serendipodous 12:50, 19 May 2008 (UTC)

[edit] plutoid?

Since there was no discussion, I automatically reverted the recent move of this article to Eris (plutoid). Now that I read the background of plutoid, I'm not opposed, but still leery of major changes to FA articles & sparking edit wars. Is this move something we all want? kwami (talk) 17:35, 11 June 2008 (UTC)

Eris is better known by the public as a dwarf planet than a plutoid. A "dwarf planet" at least uses the word planet and plutoid sounds too much like the 2006 Word of the Year: "Plutoed". Plutoid is a basically useless category that does not even need to exist! This is as bad as the whole minor planet vs asteroid discussion. -- Kheider (talk) 17:43, 11 June 2008 (UTC)
But the term "dwarf planet" is so new that's hardly an issue. Pluto is even better known to the public as a planet, but we don't keep that definition. I guess the question is whether we keep up with the IAU, and if we don't, what the lag time should be. kwami (talk) 18:17, 11 June 2008 (UTC)

Also, if we're going to move it, we should also consider moving (136472) 2005 FY9 "Easterbunny", (136108) 2003 EL6161 "Santa", and 90377 Sedna, which are plutoids "for naming purposes". kwami (talk) 18:14, 11 June 2008 (UTC)

They are NOT classified as plutoids or dwarf planets AT THIS time! -- Kheider (talk) 18:19, 11 June 2008 (UTC)
I also oppose the move; "plutoid" is a sub-category of "dwarf planet". Pluto and Eris are the only official members of the sub-category at this time, so we can't move the others. As well, moving Pluto and Eris would only confuse the issue, just as it would if we moved Earth etc. to "Earth (terrestrial planet)" and Jupiter etc. to "Jupiter (gas giant)". --Ckatzchatspy 18:38, 11 June 2008 (UTC)
FWIW, Mike Brown has his thoughts about the label up on his blog. I'm inclined to agree with his sentiment that it's existence is something of a sop to the "poor Pluto" crowd. The fact that for the forseeable future the set of dwarf planets will equal the set of plutoids plus Ceres makes it hard to see both terms ever entering common use simultaneously. For Wikipedia's purposes, it's probably more neat and tidy to keep "dwarf planet" as the more privileged categorization... obviously, we should note "plutoid" status whereever appropriate in articles, but I don't think it needs to show up in ledes or as title disambiguations.
There are two nitpicky things that caught my eye when closely reading the IAU presser, though. One, it says "The two known and named plutoids are Pluto and Eris.". Could that be taken to mean that 2005 FY9 and 2003 EL61 are indeed plutoids, effective immediately, albeit plutoids that can't be presently described as "known and ***named***"? (Going against this reading is the fact that Sedna seems to meet the H<+1 and "having a name" requirements, but doesn't get a mention.)(D'oh, Sedna's H is officially 1.6, not 0.2 as the plutoid article says)
Secondly, invoking H<+1 as a provisional lower size cutoff that allows us to presume hydrostatic equilibrium is quite a conservative line in the sand, and probably intentionally so. There's pretty strong certainty that, say, Quaoar, is in hydrostatic equilibrium, but it is nonetheless too dim to get over that absolute magnitude line. Clearly, in the name of getting the naming ball moving on some of the bigger fellers out there, it make sense that some sort of safe line be drawn in the sand first, and then thereafter a more scientific basis for calculating hydrostaticity be determined.
Now, does this H<+1 carry over to getting "dwarf planet" status? That is to say, does this definition mean 2005 FY9 meets the requirement of being both a plutoid and a dwarf planet on the basis of its absolute magnitude, or that it only meets the plutoid requirement and the floor of the dwarf planet club remains an as-of-yet undetermined? The Tom (talk) 19:12, 11 June 2008 (UTC)
Actually, I like the name. I've always disliked "dwarf planet", not because of any sentimentality that Pluto got plutoed (I was cheering it on), but because grammatically a "dwarf planet" is a kind of planet, while semantically it is not a planet. Such self-contradiction is ridiculous. "Plutoid" doesn't have any planetary pretensions. kwami (talk) 19:48, 11 June 2008 (UTC)
Agreed that the "dwarf planet" fudge is irritating, although it bears noting that "minor planets" aren't "planets," either, and that apparent contradiction hasn't ever seemed to raise hackles over the past few centuries. (Indeed, maybe the term for "dwarf planets" should have been "major minor planets" :)) I think it might have been Brown, actually, who noted that the obvious term for the dwarf planet category has been under our noses for years, namely "planetoids," but it somehow eluded everyone amidst the politicking at the IAU GA. The Tom (talk) 20:15, 11 June 2008 (UTC)
That would have been better, but 'planetoid' has long meant 'asteroid', so it would have required redefinition. Maybe they were worried about the confusion that would cause. kwami (talk) 21:45, 11 June 2008 (UTC)

[edit] Pronunciation

I had to fix the IPA for the English "r". Also, find me a source as this [ɪə] is not possible for English phonology for an initial e- Azalea pomp (talk) 23:11, 11 June 2008 (UTC)

I reverted. This is the standard pronunciation. Please follow the link to the IPA key, or the ref. to the dictionary entry. (I would have preferred /ˈiːrɪs/, but /ɪər/ is the convention that was settled on, due to objections from RP speakers.) kwami (talk) 23:21, 11 June 2008 (UTC)
OK, very odd, this may be the first English word I have seen with /ɪə/. The "r" is English is still [ɹ] and for sure not [r]. Azalea pomp (talk) 04:58, 13 June 2008 (UTC)
OK, the vowel in Eris is the same as the vowel in "pier". So yes, [ɪə] is correct, but surely this is the only Er- word pronounced as [ɪə] in English? lol Azalea pomp (talk) 05:03, 13 June 2008 (UTC)
No, /r/ is not [r], it's [ɹʷ]. But that's irrelevant in a phonemic notation. We could write it /♣/ if we wanted; it's just a convention. The conventional transcription for English ar is /r/, and that's what's used in thousands of wikipedia articles. kwami (talk)
As for other English words that start with this rhotic vowel, there's ear /ˈɪər/, and of course here in aitch-dropping dialects. Era has both of the pronunciations we attribute to Eris, as do quite a few -eris words. The American Heritage dictionary has both /ˈɪərɪs/ and /ˈɛrəs/, whereas Encyclopedia Mythica has only the more anglicized /ˈɪərəs/. kwami (talk) 05:44, 13 June 2008 (UTC)