Talk:Hilda asteroid

message: What's this bit about not forming a true asteroid family because they don't "descend from a common parent body"? As I understand, an asteroid family is defined by having common orbital elements--anyway, is it even commonly accepted that any of the asteroids have a common parent body? I'm going to comment it out as OR. --Aelffin 17:06, 30 August 2006 (UTC)
replies: text: Okay, I read about it in Asteroid family and I stand corrected. It just struck me as wrong at first. Referencing would certainly help though. --Aelffin 14:17, 31 August 2006 (UTC)
replies: text: I can accept that, but I haven't been able to find "just the right reference", you know?  It's all a few references plus a little inference plus general OR hanging out with other astronomers. WilyD 14:19, 31 August 2006 (UTC)
replies: text: A little bit of OR never hurt anybody; at least not when it comes straight from the proverbial horses' mouths. --Aelffin 15:00, 31 August 2006 (UTC)
thread_title: Family

message: In one place this article says the Hilda asteroids are in 2:3 resonance with Jupiter; in another it is 3:2.  Which is it? -- 23:26, 5 August 2009 (UTC)
replies: text: Sorry for the late reply Larry. Using asteroid 153 Hilda as a generic example, it goes around the Sun 3 times (7.92 year orbit) for every 2 times that Jupiter does (11.8 yer orbit). -- Kheider (talk) 15:43, 30 April 2010 (UTC)
replies: text: The article is still inconsistent though, saying in the intro that they are in 2:3 resonance and another time saying they are in 3:2. Based on the dicussion and the article Orbital resonance, we may use the following convention: "saying that B has an n:m resonance with A is a shorthand for saying that (secondary body) B completes n orbits in the same time as (primary body) A completes m orbits.". Using this convention, Hildas have a 3:2 resonance with Jupiter. We can also say that there is a 3:2 Hildas-Jupiter resonance. I'll amend the article in this way.--Joancharmant (talk) 10:09, 10 December 2011 (UTC)
thread_title:  Which resonance? 

message: The eytomology needs to be included.174.3.123.220 (talk) 04:26, 20 May 2010 (UTC)
thread_title:  Etymology 

message: The Article should say whether similar families are known to exist, for other planets and/or other resonance ratios. 94.30.84.71 (talk) 10:10, 16 June 2012 (UTC)
replies: text: No it shouldn't, that's the job of asteroid family. SpinningSpark 15:59, 16 June 2012 (UTC)
thread_title:  Similar families? 

message: Dear main authors; thank you for the good work. I am not happy with the sentence: "Consequently, a Hilda's orbit has a semi-major axis between 3.7 AU and 4.2 AU, an eccentricity less than 0.3, and an inclination less than 20°."
*I deleted the word "consequently", because this sentence doesn't follow from the previous text. 
*The 3:2 resonance corresponds to a semi-major-axis of 3.97 AU (~4, as stated below). Can asteroids with semimajor axis 3.7 and 4.2 AU be called in orbital resonance with Jupiter? The corresponding orbital period ratios are 1.67 and 1.37. This needs clarification. 
Regards, Herbmuell (talk) 03:15, 27 January 2016 (UTC)
replies: text: Resonances have a finite width, due to the planetary perterbation.  The semimajor axes change with time.  The *average* value must be ~3.97, but the instantaneous value can be farther away, as it librates around. Kepler47 (talk) 20:13, 10 November 2016 (UTC)
replies: text: I see. I added this information in the article. --Herbmuell (talk) 16:05, 19 November 2016 (UTC)
thread_title:  Please improve sentence 

message: Ref. 4 of the article, Brož, M.; Vokrouhlický, D. (2008), can be downloaded from arxiv. These authors call the Hilda asteroids a group, and so does the beginning of this article. The group consists of two families, the Hilda family and the Schubart family; the article also says so.  Clearly, this article is about the Hilda group, and not the family. I suggest therefore to rename it "Hilda group". If we can agree on this terminology, the articles 153 Hilda and 1911 Schubart would then also have to be corrected similarly (distinction between group and family). See also the articles Asteroid family and List of minor-planet groups on this topic. --Herbmuell (talk) 15:07, 19 November 2016 (UTC)
replies: text: I agree, there are other articles on wikipedia with the same error, for example the Hungaria_family Agmartin (talk) 20:59, 19 November 2016 (UTC)

text: The papers discussing them typically refer to them as Hildas or Hilda asteroids. Agmartin (talk) 21:41, 20 November 2016 (UTC)
thread_title:  Suggest renaming and further editing 

message: How stable are the orbits of these asteroids? The main article sort of SUGGESTS, without actually explicitly saying, that they are stable for a long time. That is, that their Keplerian elements change only very "slowly". But how "long" is "long? Hundreds of years? Thousands? Millions? And how do their orbits "decay"? 
On a related topic ... "The Hildas Triangle has proven to be dynamically stable over a long time span". What exactly does this mean? Is this the same thing as the previous question? If not, then what is it? And again, what is a "long time" in this context? So many questions...  — Preceding unsigned comment added by 2001:8003:E422:3C01:BCD6:9922:BB24:C3D0 (talk) 09:22, 30 December 2021 (UTC)
thread_title:  Long term stability? 

message: It needs to be explicitly stated that these asteroids orbit around THE SUN, not Jupiter. Even though the animations and the diagrams make this clear, well at least to me. I say this because in the Talk section for the Trojan asteroids, which whilst of course different from the Hildas, do arguably share some common factors with Hildas, there is quite a bit of confusion about this.  — Preceding unsigned comment added by 2001:8003:E422:3C01:BCD6:9922:BB24:C3D0 (talk) 09:27, 30 December 2021 (UTC)
thread_title:  One phrase missing from all of this. 

message: There should be a bit of a discussion of this. In this discussion shoudl be included something like the following:
From the diagram with the red and green orbits, it can be seen that the closest approach between asteroid and Jupiter - that is, when Jupiter is in opposition - occurs when the asteroid is at perihelion, and thus at its furthest from Jupiter. This would presumeably minimise the gravitational perturbation of Jupiter. 
Also .... is this the case for ALL Hilda asteroids, or only Hilda itself? — Preceding unsigned comment added by 2001:8003:E422:3C01:C2D:60A8:DA74:74FD (talk) 22:33, 30 December 2021 (UTC)
thread_title:  PErturbation of their orbits by Jupiter. 

message: You have: "The Hildas "rest" at their aphelia in the apexes for an average of 5.0–5.5 years, whereas they move along the sides more quickly, averaging 2.5 to 3.0 years. "
This seems very incorrect. If you look at the animated gif, the aphelion "rest" is more like 2-3 years, and the "rapid siding" is more like 5-6 years.
Also, it is perhaps way too simplistic to describe this with one set of values. Orbits with low eccentricities, such as Hilda herself, have "sharp" apices, like the red one, and the "rest" period is relatively short. Orbits with larger eccentricities have "lobes" at their apices, like the black one, and the "rest" period is much longer.  — Preceding unsigned comment added by 2001:8003:E422:3C01:B5C0:7521:E3E5:C5E7 (talk) 03:29, 1 January 2022 (UTC)
thread_title:  Two nurmber either incorrect; or need more explanation.