Thank you so much Tony. I see that I have to click on each observation in the lower text box to see its x in the display below it. |
and I see now how to toggle it back on and do full step as you suggest. I have it working now. yippeee
This is wonderful.
Charles
________________________________
From: aje160744 <
tony.evans@...>
To:
find_orb@yahoogroups.com
Sent: Monday, June 24, 2013 11:16 AM
Subject: [find_orb] Re: Comet 39P/Oterma
Charles,
I just got the obs for 39P from the MPC and fed them to Find_Orb. It comes up quickly for a solution for the 1958-9 period with the rest of the obs filtered out. Gradually toggle some additional obs "on" and do a full step. Repeat until all the obs are included. Make sure all perturbers are on when doing this. I got to a residual of 0.741" with the worst dozen observations toggled off. That's not bad seeing as many of those old obs are probably a bit shaky. Monte Carlo ran with that solution giving residuals of around 1".
Initially Find_Orb set the epoch at 1959 Mar 29. Orbit a= 3.96, e=0.145. I Changed the epoch to 2013 Jun 24 (+remove worst dozen obs) and the new solution had a residual of 0.743", a=7.37, e=0.235.
Yes, some dramatic changes of orbit!
Tony
--- In find_orb@yahoogroups.com, "cbellh47" <charbell@...> wrote:
>
> I wanted to investigate the orbit of 39P/Oterma by generating some test particle clones. However, I can't get an orbit solution from the observations in MPCOBS. I know that the object encountered Jupiter in 1963 and shifted its orbit semi major axis from less than a_Jupiter to grater than a_Jupiter. So I tried to get an orbit to calculate using observations from before the encounter and again with observations from after the encounter. I also tried to constrain to known MPC orbit values and orbit epoch values. There are MPC orbits for 7 epochs.
>
> I must be missing something.
>
> I have no troubles with other objects so far.
>
> I give in and ask for help or ideas.
>
> Charles
>
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