Gravity Simulator - Neptunian Trojans

frankuitaalst

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Neptunian Trojans
02/01/09 at 07:02:04

A while ago (2006) Tony made this simulation of the 4 known Neptunian Trojans .
http://orbitsimulator.com/gravity/simulations/NeptuneTrojans.gsim

Beeing occupied for a while by the Neptunian resonances I discovered in the Wiki Pages the number of known Trojans has grown to six nowadays .
All of them are correlated with the L4 point , but each of them has its particular orbit .
The animation herunder shows the path of the 6 Trojans in rotating frame to Neptune .
Each frame covers 164.8 years . Simulation was run for 14500 year from now.
Initial conditions : courtesy of JPL minor body center .

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Neptunian_Trojans.gif

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atomic7732 Full Member Kalassak, Paladin of Storms Posts: 149 Gender:	Re: Neptunian Trojans Reply #1 - 02/01/09 at 07:24:08 that is awesome! so all are in a 1:1 right?
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frankuitaalst Ultimate Member Great site Posts: 1510 Gender:	Re: Neptunian Trojans Reply #2 - 02/01/09 at 07:55:17 Quote from NeutronStar on 02/01/09 at 07:24:08: that is awesome! so all are in a 1:1 right? Yes , right . To be more precise : they all librate around the 1:1 resonance , i.e . they tend to be stable at the L4 point , but "overshoot" and then "decelerate" again .
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EDG Ultimate Member oh, crumbs!!! Posts: 611 Gender:	Re: Neptunian Trojans Reply #3 - 02/01/09 at 09:28:17 What exactly is Uranus' orbit doing? Is that "flexing" a resonance?
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frankuitaalst

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Re: Neptunian Trojans
Reply #4 - 02/01/09 at 10:13:14

Quote from Mal on 02/01/09 at 09:28:17:

What exactly is Uranus' orbit doing? Is that "flexing" a resonance?

Uranus has P 84 y , Neptune has P 164.8 years . So they are almost at 1:2 resonance . If they had been at 1:2 resonance Uranus orbit would appear elliptical and stable . As this isn't the case the orbit seems to precess ...
I don't think Uranus will ever come in resonance with Neptune

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kheider

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Re: Neptunian Trojans
Reply #5 - 02/01/09 at 10:20:34

Quote from Mal on 02/01/09 at 09:28:17:

What exactly is Uranus' orbit doing? Is that "flexing" a resonance?

Uranus is near (coincidental) the 2:1 resonance with Neptune, but it does not librate, thus we get more of a constant 360 degree wobble. See 2 Pallas on wikipedia for a good example of a non-librating near resonance.
http://en.wikipedia.org/wiki/2_Pallas#Characteristics

Frank;
Which trojan is producing the central poorboy valentine day heart?

Might be nice to have have a simple animation with just him given that valentine's day is coming.
-- Kevin

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frankuitaalst Ultimate Member Great site Posts: 1510 Gender:	Re: Neptunian Trojans Reply #6 - 02/01/09 at 10:36:53 Nice find ! Don't know . I'll isolate it !
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Tony YaBB Administrator Posts: 1060 Gender:	Re: Neptunian Trojans Reply #7 - 02/01/09 at 11:16:40 btw... the heart shape, and all the other strange shapes are artifacts of the viewing angle. If viewed top-down on the orbital plane of the asteroid, it would be a simple oval.
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atomic7732

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Re: Neptunian Trojans
Reply #8 - 02/01/09 at 13:17:26

Quote from Tony on 02/01/09 at 11:16:40:

btw... the heart shape, and all the other strange shapes are artifacts of the viewing angle. If viewed top-down on the orbital plane of the asteroid, it would be a simple oval.

Take inclination into account too! Izdubar (a co-orbital with earth) make a shape wiht a loop, somwhat like a heart, from top-down.

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atomic7732

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Re: Neptunian Trojans
Reply #9 - 02/01/09 at 13:19:10

Quote from frankuitaalst on 02/01/09 at 10:13:14:

Quote from Mal on 02/01/09 at 09:28:17:

What exactly is Uranus' orbit doing? Is that "flexing" a resonance?

Uranus has P 84 y , Neptune has P 164.8 years . So they are almost at 1:2 resonance . If they had been at 1:2 resonance Uranus orbit would appear elliptical and stable . As this isn't the case the orbit seems to precess ...
I don't think Uranus will ever come in resonance with Neptune

So, that's what they went looking for Neptune for... When they saw that Uranus was not where it was supposed to be they proposed Neptune. And found it!

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kheider

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Re: Neptunian Trojans
Reply #10 - 02/01/09 at 21:23:53

Quote from frankuitaalst on 02/01/09 at 07:02:04:

I discovered in the Wiki Pages the number of known Trojans has grown to six nowadays.

I have added your animation to the Neptune Trojan article at:
http://en.wikipedia.org/wiki/Neptune_trojan

(You can click on the image to bring up the full size one and to get more details about the image.)
-- Kevin

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kheider

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Jupiter Trojan
Reply #11 - 02/01/09 at 21:43:02

Currently at Wikipedia, Jupiter Trojans is undergoing a wikipedia peer review for improvement. They have a generic animation of the orbit of 624 Hektor compared to Jupiter, but I am sure GravSim can do better. I recommend 624 Hektor because it has the best developed Jupiter trojan wiki article.

http://en.wikipedia.org/wiki/Jupiter_Trojan

-- Kevin

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frankuitaalst

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Re: Neptunian Trojans
Reply #12 - 02/02/09 at 09:46:06

Quote from kheider on 02/01/09 at 21:23:53:

Quote from frankuitaalst on 02/01/09 at 07:02:04:

I discovered in the Wiki Pages the number of known Trojans has grown to six nowadays.

I have added your animation to the Neptune Trojan article at:
http://en.wikipedia.org/wiki/Neptune_trojan

(You can click on the image to bring up the full size one and to get more details about the image.)
-- Kevin

I saw the picture looks a little bit "spicky" due to the downsizing of the original .
I ran the simulation again in a smaller screen for 9000 years .
This animation should be better looking ...

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Neptunes_Trojans_Animation_9000_y.gif

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frankuitaalst

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Re: Neptunian Trojans - side view
Reply #13 - 02/07/09 at 05:20:57

The picture above shows the 6 known Neptunian Trojans on a normal rotating frame to Neptune .
In order to represent somehow the strong inclination of some of these trojans I created the same simulation , but this time viewed from aside ( to be more precise : Y,Z representation) . You can interprete the animation hereunder as if you were looking at the animation above from the right side .
Simulation runs for ca. 9400 years , corresponding with the libration period .
Jupiter and Saturn aren't represented .
An interesting by-product is the strange flexing orbit of Uranus in this view which I don't fully understand .

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NeptuneTrojansSideOnAnimation9400y.gif

« Last Edit: 02/07/09 at 07:30:42 by frankuitaalst »

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frankuitaalst Ultimate Member Great site Posts: 1510 Gender:	Neptunian Trojans Reply #14 - 02/14/09 at 07:39:56 As a present for Valentines day : here's the orbit of 2005TN53, a trojan of Neptune . Simulation was run for ca. 10.000 y .
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