Astroblog: Comet 103P/Hartley near Mel 71

Thursday, November 25, 2010

Comet 103P/Hartley near Mel 71

Comet 103P Hartley near the open cluster Mel 71 on November 23, The image immediate left is a cropped shot from Global Rent a Scope GRAS-05 (click to embiggen).

Despite strong Moonlight I think it came out rather well.

The image is a stack of 3 x 30 second images with dark frame subtraction stacked in Image J using Z projection of maximum intensity and a lot of contrast fiddling. I still can't work out how to subtract flatfields correctly though.

This is a widefield image of the same area in GRAS 14. This is a colour series stacked in Image J using its colour series module.

The colour is pretty rubbish (but hey, I'm red-green colour blind), but you can clearly see the comet near Mel 71, Mel 72 off on the right hand side of the image and NGC2423 off to the left. You definitely need to click to embiggen this one.

I have no idea why the colour is so weird here, my previous colour shots have been fine. Well, I have the originals to play around with.

I still have a whole bunch of 103P images to post, and lots of 103P news as well (and 2010 V1 image links). The comet is going to be in spectacular territory in the next few days, but strong Moonlight is a problem.

Labels: astrophotography, comets, Global Rent-a-Scope