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What about a 2:5 resonance?

Pluto is not a Plutino according to David Jewitt, the astronomer who coined the term. "Plutino" means "little Pluto", and since Pluto is a standard-sized Pluto, it couldn't be a "little Pluto." JoelWest 07:37, 13 Apr 2004 (UTC)

On the other hand, you don't have to have a big Gian and a little Gian to call Gian "Gianino." Pluto is little, and it is Pluto. "Plutino" could just be an affectionate diminuitive. --Chronodm 23:17, 1 November 2005 (UTC)

A reasonable definition of plutino is "a minor planet in 3:2 resonance with Neptune". But perhaps a more useful definition is simply "an object in 3:2 resonance", which (1) bypasses the whole "is Pluto a minor planet?" controversy and (2) allows for economy, so that you can write simply "the plutinos" instead of "the plutinos and Pluto" every time you need to refer to such objects.
Narrow etymological considerations are not the sole consideration. Consider the fact that Hawaii has interstate highways... ponder that for a moment. If it really mattered, you could propose a name change to "plutowano" or something, by analogy with "cubewano", but most people would just shrug and go on using "plutino". -- Curps 07:47, 14 Apr 2004 (UTC)

I just updated the article List of trans-Neptunian objects, but got confused about that Pluto's satellite Charon was described as a Plutino in this article. I assumed this was in order and just added it as its type there, but I don't really see how it would be one according to the definition (orbit similar to Pluto's -- which it clearly isn't, as it doesn't even orbit Sun, but Pluto). Jugalator 22:11, Jul 16, 2004 (UTC)

Plutino most likely is going to be redefined as a 200yr orbit planet by the IAU. This article should refect that discussion. see talk:planet talk:pluto talk:ceres Hopquick 15:08, 16 August 2006 (UTC)

You're thinking of Plutons, not Plutinos. DenisMoskowitz 15:25, 16 August 2006 (UTC)
LOL, my bad. Hopquick 15:45, 16 August 2006 (UTC)

Orbital period[edit]

Should the article contain some mention of the fact that Plutinos all have orbital periods around 247.5 years? The fact that they'd all have similar periods would be implied by the fact that they're in resonance, but might it be good to mention the approximate period just so the reader doesn't have to chase off to the Neptune article and multiply by 1.5, or into one of the individual plutino articles to find the period? Linguofreak 20:36, 24 August 2006 (UTC)

Good idea. Deuar 09:28, 25 August 2006 (UTC)


Excuse me, but "plutino" means "little Pluto". How can Pluto itself be a little Pluto? 00:43, 26 December 2006 (UTC)

The "little pluto" translation into Italian is related to the etymology of the word. Its meaning has since moved on, and plutino no longer actually means "little pluto", but refers to a class of orbits. Deuar 14:33, 5 January 2007 (UTC)

3:2 resonance or 2:3 resonance[edit]

From what I've gathered on Google Scholar, Pluto and the Plutinos have a 3:2 resonance with Neptune. It's Neptune that has a 2:3 resonance with them. Googlefight reveals 9350 hits for Pluto "3:2 resonance" vs. only 577 for Pluto "2:3 resonance". Certainly David Jewitt, who coined the term Plutino, refers to them possessing a 3:2 resonance. [1] Serendipodous 09:25, 5 April 2007 (UTC)

Hi; This seems to be an issue that is as old as the hills, and continually hard to resolve. I would take the above googlefight values with a big grain of salt. A manual search of Google scholar (ticking the "only physics, astronomy and planetary science" box) gives much more even results:
  • a search for pluto "2:3 resonance" gives 100 hits
  • pluto "3:2 resonance" gives 173 hits.
However, and here's the surprising part, it's difficult to make sure that it's actually pluto that is being talked about!
  • a search for neptune 2:3 resonance" gives 130 hits
  • neptune "3:2 resonance" gives 217 hits
Note how 3:2 appears to win by a similar margin whether we're talking about pluto or neptune! There is no clear indication of which is preferred, at least from a search for these terms. Deuar 20:22, 10 April 2007 (UTC)

It seems to be mostly author’s preference with specialist articles on orbit dynamics typically using p:q where p<q and non-dynamics_specialist use 3:2. Non–scientific articles used mostly 3:2. Plutinos orbit twice when Neptune orbit 3 times, so 2:3 seem less misleading to many. To keep NPOV maybe a short statement should be added to the article. Eurocommuter 06:04, 15 April 2007 (UTC)

At the very least, pick one and be consistent: having two consecutive passages (the redirect line and the first paragraph) conflicting is just silly. DewiMorgan 15:48, 18 May 2007 (UTC)

Well, after a one month delay, they're at least finally consistent. Deuar 20:14, 16 June 2007 (UTC)

2007 NC7[edit]

2007 NC7 can be removed, it now has a second opposition observed giving it a semi-major axis of 33.7+-0.5 au. See —Preceding unsigned comment added by (talk) 13:16, 8 July 2008 (UTC)


Are there any generalizations of Plutinos that can be made, such as Orcus being the "anti-Pluto"? If it's only that one case, we can cover it at Orcus, with just a mention here; otherwise we should cover it in greatest detail here. — kwami (talk) 17:08, 19 September 2010 (UTC)