Astroblog: Comet Al Recovers Comet P/2003 K2

Saturday, December 13, 2008

Comet Al Recovers Comet P/2003 K2

The fuzzy dot bracketed by the yellow lines at the bottom of this image is at the time of writing has been identified as comet P/2003 K2 (Christensen) .

Our own Comet Al discovered the comet on images from the STEREO SECCHI instruments. Originally it looked like this was going to be the first non-Kreutz comet discovered from STEREO spacecraft data.

Unfortunately, this was not to be, but it was the next best thing. Some excellent sleuthing by Rainer Kracht and Maik Meyer suggested that this was the previously discovered periodic comet 2003 K2, which had not been recovered since its discovery. Ranier derived orbital elements and Maik recognised them as P/2003 K2. Brian Marsden has now confirmed this identification. This is the first time a comet has been recovered (as opposed to discovered) from STEREO data. Congratulations Comet Al and all the stereohunter folks for this fantastic recovery.

You can get an AVI (680K) of the comet here, and an animated GIF (530K) here. The comet is pretty hard to observe from ground based observatories at the moment, disappearing into the twilight. But in January it will become visible to telescopes. See here for orbital elements and predictions.

Why is recovery important? The orbital elements of a newly discovered comet can be imprecise, especially if it can only be observed for a short part of its path. So there may be some uncertainty in predicting when and where a new comet will return. In the case of P/2003 K2 (Christensen) the orbit was uncertain by about 1 month, so picking it up again was not trivial. Looking for a faint object when you can be several telescope fields away from its real position can be a pain. Congratulations again Comet Al!

Labels: comets, Stereo Satellite

# posted by Ian Musgrave @ 7:49 am

Comments:

Gidday Ian, thanks for the blog notes and the images are looking good. I just loaded the orbit data into Starry night. The comet is 8 degress from "Smily Fritz". Could be in a few wide shots?
Its amazing what you find while eating a bowl of porridge.
Kind regards, Cometal

# posted by

Anonymous : 4:34 pm

G'Day Al

No worries, you did all the hard work finding the comet. You are right! The comet is above "Smiley Fritz" (as, ironically, is 2008 X4 Christensen). I'll ask around and see if anyone picked anything up.

# posted by