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夜殘花影透窗紗,

北斗依稀南斗斜。

叵奈春心似流水,

暗隨明月到天涯。

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EXORB

I’v been attempting to employ EXORB to perform orbital calculations lately. Before I always used FindOrb, another outstanding toolkit to carry out similar functions, however, I’v been told that EXORB prevails FindOrb in finding linkages. I once fed da known Kracht sungrazer linkage 2005 W4 = 2011 E1 to FindOrb, and consequently da outcome went outrageous even though constraints hav been set. It made me even more determined to master EXORB.

D interface:

My first attempt was quite simple — to compute orbital solutions for da newly discovered comet P/2011 V1 (Boattini). My settings are as follows:

Obtaining da solution was not that easy as I’d expected. Da value in toggle D had been repeatedly tested until da program rendered me a reasonable solution, which can b seen as follows:

N da residuals:

N da error n correlation matrix:

Da solution’s quite close to d one given by MPEC K11-V13.

Then I proceeded to calculate orbits for sungrazing comets observed by LASCO. For reference I first tried to solve a comet in a single apparition. Here I take C/1996 X3 as d example.

Da toggles are set to a bit different from those used for finding orbital solutions for P/2011 V1:

A parabolic solution is assumed before da computation. Noticeably da program tends not to give me an orbital solution that “seems like” a Kracht sungrazer. Instead, it frequently rendered me a retrograde orbit, with relatively large residuals. Therefore I had to repeat da computation again n again, until a reasonable solution was found:

Da residuals:

Da next step is to save da raw solution in STATING.DAT, which will automatically return to da toggles n toggled off U. Then I set X to 3.2 n perform da calculation again:

Now I toggle on K as well as 1, 2, 3, 4, and 6:

Now add a new apparition to C/1996 X3, turn off 1, 2, 3, 4, 6 n toggle on 5:

At last, toggle on 1 to 6:

Residuals:

Error n correlation matrix:

Strictly speaking, I ought to delete those observations that generate large residuals. However, I found that all observations from 1996 lead to da largest residuals. If I remove them all, da linkage solution turns to meaningless. I suspect my solution for da single apparition for C/1996 X3 wasn’t da best solution, but a solution with residuals in da proximity of its local minimum. Anyway, it’d b a successful linkage solution.

My goal’s to master da way to find out da linkage solutions for an object from arbitary num of different apparitions. Evidently before I achieve it I still got a arduous journey to get hang of EXORB.

EXORB