Monday, May 17, 2010

Comet McNaught

I'm working on a post for the Kitt Peak "Star-B-Que" that the Tucson Amateur Astronomy Association held last night at the Observatory's picnic area. Lots of pics to show, but haven't had a chance to sit and write text, so it will wait for tomorrow.

However, I was impressed by a little comet, Comet C/2009 K5 McNaught, discovered last year by Robert McNaught, who lives in Australia working for a NASA project searching for interplanetary interlopers. While not spectacularly bright, nor sporting a spectacular tail, it is likely the brightest in the sky right now at magnitude 8.3 as recently as a week ago. It is also easy to find with a small telescope in a dark sky - currently right below Polaris! The following picture (cropped from exposures taken with the Canon XSi and a 70-200 zoom set to 100mm) shows 7 co-added exposures of 150 seconds each. Polaris is at the top, the bluish comet near the bottom. The fuzzy spot below Polaris is NGC 188, an open star cluster. Note that in the blowup of the comet, it's motion is shown as a streak during the sequence of exposures. If the pictures are co-added such that the comet is tracked, the stars trail, but the comet and very faint tail is now sharp.

The comet is slowly moving away from both the Sun and Earth (about 140 million miles from each), so it won't be getting any brighter, but it is always fun to see one of these "dirty snowball" visitors!

1 comment:

Anthony Vodraska and Anita Gilbert said...

Nice astro-images of the comet. I will get my little Questar out and view it while I still can.