M81, M82 and NGC 3077 in Ursa Major
Copyright 2005 Hap Griffin
At the lower middle is one of the showpiece galaxies visible in even the smallest telescopes, M81. Also known as Bode's Galaxy, it is the dominant galaxy in the M81 group, which includes M82 to it's right and NGC 3077 to the upper left and several other small galaxies not shown. M81 and M82 are locked in a gravitational tug-of-war which has lasted over the past billion years. These two galaixes rotate around each other with a period of approximately 100 million years. The last few rotations have taken a toll on both members, M82's gravity having raised circulating density waves rippling around M81 resulting in the richness of M81's spiral arms. M81, though, left M82 a messy pulp of exploded stars and colliding gas so violent it emits bright X-rays. In both galaxies, colliding gas has created a recent abundance of bright new stars indicated by the blue color in M81's spiral arms and M82's outer regions. In a few billion years only one galaxy will remain. NGC 3077 is an irregular galaxy, having also suffered disruption of its outer regions due to gravitational interaction with its neighbors.
These galaxies lie at a distance of approximately 12 million light years.
1,418 stars in this photograph.
February 5, 2005 Griffin/Hunter
Observatory Bethune, SC
Instrument: Canon 300D Digital SLR (modified) through Orion ED80 w/ Meade .63 Focal Reducer piggybacked on LX-200
Focal Ratio: Approx. f4.5
Guiding: Auto through LX-200 w/ SBIG ST-237
Conditions: Visually clear
Weather: 33 deg. F
Exposure: 45 minutes total @ ISO 800 (9 x 5 min exposures) calibrated with flat frame and Master Dark frame (median combine of 9 darks)
Filters: Baader UV/IR Block
Processing: Focused and captured with DSLRFocus. RAW to TIFF conversion, frame calibrations, Digital Development, Adaptive Richardson_Lucy deconvolution, scaling and JPEG conversion with ImagesPlus. Frame alignment in Registar. Noise reduction with NeatImage.