Lexington, Mass. Suburban skies; 50-45F, low humidity and clear; comet high in the sky

October 8, 2010, 12:24am to 3.54am; in the image above, the comet is located at its 12:24am position (see explanation below)

Takahashi E160 astrograph (6" F/3.3) with field flattener and CLS Astronomik filter

Image scale is about 1.5deg x 2.0deg


Takahashi EM-1 mount; unguided; tracking stars

Canon 450D (modified by Hap Griffin)


84 subs of 120sec each (total exposure 2h 48m); 1600 ISO

20 darks, 20 flats, 20 bias files; processed as usual


Captured with Mike Unsold's ImagesPlus 4.0; processed with ImagesPlus 3.82, Photoshop C4, and Noise Ninja


Procedure: (1) comet aligned and stacked; (2) stars aligned and stacked; (3) images blurred and recombined as explained below.


Explanation of procedure: Same general procedure as for Comet McNaught on this site, developed by Bernhard Huble. In this case, the set of images was first separated into 5 batches to ensure clear separation between stars; thanks to Dennis Persyk for this tip.