M82: This is a magnitude 8.4 irregular galaxy in Ursa Major, presenting to us edge-on. It is a spectacular example of a "starburst galaxy," having undergone a relatively recent collision or near-collision with its much larger neighbor, M81 (most estimates put this as having happened about 600 million years ago). The gravitational forces in such events typically cause a surge in star-forming activity, and M82 is also rich in X-rays. It is estimated to be approximately 11 million light years from earth, and approximately 25,000 light years in diameter.

Technical Information:

LRGB: 124:40:40:72 (L, R and G were integrations of four minute images, all unbinned; B was an integration of eight minute images, all unbinned).

Equipment: 10" LX200 at f/4.6, and an SBIG ST-7E camera/CFW-8 color filter wheel

Image Acquisition/Camera Control: CCDSoft V5.

Processing: All images calibrated (darks and dawn flats) and registered in AIP4WIN. Luminance and color channel images mean combined using Ray Gralak's sigma reject program. Luminance layer run through DDP in AIP4WIN. Color combine, and adjustment of curves and levels, performed in Photoshop 5.5.

Location: My yard in Redmond, Washington, elevation 500'.

Date: All images taken during the night of 3/2/02.

Moon Phase: Waning Gibbous.

CCD Temperature: -30C

Copyright Mark de Regt, 2002