Talk:Cybele asteroids

Resonance?

The claim that Cybele asteroids are in a 7:4 resonance (or any resonance) with Jupiter is not true. I don't know why this was changed in 2018 without explanation. The claim has since made it into all the lists of numbered minor planets (random example), and without doubt into many articles about individual asteroids (example). It was also stated (without source) in Kirkwood gaps until moments ago, and is falsely stated in Hecuba-gap asteroid. List of minor-planet groups says so, too, giving this reference; there is nothing about the 7:4 resonance in that book. The user who has added it in 2018 is no longer active. Renerpho (talk) 21:24, 6 March 2025 (UTC)[reply]

I am notifying Exoplanetaryscience, with whom I discussed the issue before posting here, and Tom.Reding as the last human to have edited the article (16 November 2023). Given the enormous number of pages that are affected by the error (mainly the numerous lists), I will also ask for help on WP:AST. Renerpho (talk) 21:24, 6 March 2025 (UTC)[reply]

I have started to remove unsubstantiated claims of a 7:4 resonance. I have removed it from about half a dozen general astronomy articles so far, and from the first 30 of the sub-lists of numbered minor planets (out of a a couple hundred sub-lists that need to be changed). Renerpho (talk) 22:29, 8 July 2025 (UTC)[reply]

I agree. The Cybele don't appear clustered around any resonance in Carruba et al. 2013 figs 13-15 (p21), and Vokrouhlicky´ et al. 2010 (p3/2149) states "Technically, the Cybele population objects have orbits in between the J2/1 and J3/2 (Hilda) mean-motion resonances with Jupiter." ~ Tom.Reding (talk ⋅dgaf) 18:01, 20 July 2025 (UTC)[reply]

@Tom.Reding: Thanks! As a related question, what does the statement that the Cybele asteroids are a "dynamical group" mean? This article links to List of minor-planet groups, which doesn't include the word "dynamical". Renerpho (talk) 19:58, 20 July 2025 (UTC)[reply]

Members of a dynamical group share orbital elements, and don't necessarily share chemical makeup, albedo, etc., usually due to a collision. ~ Tom.Reding (talk ⋅dgaf) 20:47, 20 July 2025 (UTC)[reply]

@Tom.Reding: Maybe we should make that clearer. There's no link to dynamical system anywhere on the relevant pages. Renerpho (talk) 21:11, 20 July 2025 (UTC)[reply]

I am asking because, in that case, we should probably apply that change everywhere.[1] Renerpho (talk) 12:41, 21 July 2025 (UTC)[reply]

@Renerpho: you got a bit overzealous and removed valid Cybele asteroids, including 65 Cybele itself. Please restore these and only remove unconfirmed, italicized 7:4 Cybele, i.e. [[Cybele asteroid|''7:4'']], [[Cybele asteroids|''7:4'']], ''7:4''. ~ Tom.Reding (talk ⋅dgaf) 12:09, 2 August 2025 (UTC)[reply]

@Tom.Reding: If you can show me a Cybele asteroid that's in 7:4 resonance with Jupiter, I'll be happy to restore that in the table. 65 Cybele is not in resonance. Renerpho (talk) 13:21, 2 August 2025 (UTC)[reply]

Cybele asteroids are still Cybele asteroids, regardless of resonance misinformation. The resonance portion of true Cybele should of course be removed, but the group designation should remain for confirmed members. ~ Tom.Reding (talk ⋅dgaf) 14:23, 2 August 2025 (UTC)[reply]

I'd be fine with that. What I was removing were references to the 7:4 resonance (which is what had been displayed in all of these cases). I have no issue with replacing that with a link to Cybele asteroids. What you're suggesting is to write CYB or CYB (depending on whether it's confirmed or not), in analogy to what we're doing with Hungaria asteroids? But the Hungaria family is an actual asteroid family, not a dynamical group, so I'm not sure if that's appropriate. Renerpho (talk) 14:52, 2 August 2025 (UTC)[reply]

Cybele are listed at Asteroid family#Other families or dynamical groups, so CYB/[[Cybele asteroids|''CYB'']] is appropriate, though I suspect the unconfirmed population is very small. ~ Tom.Reding (talk ⋅dgaf) 15:26, 2 August 2025 (UTC)[reply]