M82 - Irregular Galaxy in Ursa Major


Copyright 2007 Hap Griffin

M82 is one of a pair of galaxies in the constellation Ursa Major that is well known by all amateur astronomers.  M82, along with its partner M81 (shown HERE) can be seen as a pair in the same field of most small telescopes (a wide field image is HERE).  While M81 is a beautiful spiral, M82 is an irregular type galaxy and furthermore seems to have been disrupted by a relatively close passage some 300 to 600 million years ago of its partner.  Irregular lanes of dust and high rate star birth activity can be seen across its central region.  The turbulent explosive gas flow is also a strong source of radio noise.  

M82 lies at a distance of 12 million light years.  


Date/Location:    December 8, 2007     Griffin/Hunter II Observatory    Bethune, SC
Instrument:    Canon 40D (modified IR filtering) Digital SLR through 10" F/4.7 Newtonian w/ Baader MPCC 
Focal Ratio:   F/4.7 
Guiding:    Auto via SBIG ST-237 through Orion ED80 refractor
Conditions:    Visually clear
Weather:    45 F
Exposure: 228 minutes total (76 x 3 minutes @ ISO 800)
Filters:    Baader UV/IR block internal to camera
Processing:    Focused, captured, RAW to TIFF conversion, calibration, alignment, stacking, Digital Development, Richardson-Lucy deconvolution, resizing and JPEG conversion in ImagesPlus V3.  Final tweaking in Photoshop CS2.