by Craig and Tammy Temple
Messier 81 (NGC3031), or Bode's Galaxy, is the largest in a group of 34 galaxies known as the M81 Group. At a mere 11.7 million light years distant, it is one of the closest galaxy groups to the Local Group, which contains our own Milky Way. M81 was discovered in 1774 by Johann Elert Bode and is easily seen at a magnitude of 6.94. Bode's Galaxy is caught in a gravitational struggle with nearby M82 (NGC3034), the Cigar Galaxy. M82 displays violently rapid star formation that is thought to be the result of intense gravitational deformation caused by it's neighbor, M81. In spite of this star formation, The Cigar is slightly dimmer, at a magnitude of 8.41.
Telescope: Astro Tech AT8IN 8” f/4 Newtonian
Accessories: Baader MPCC
Mount: Orion Atlas EQ-G controlled by EQMOD
Guiding: Orion StarShoot AutoGuider on William Optics ZS66
Camera: Canon Digital Rebel T1i, Hap Griffin Baader modified
Filters: Astronomik CLS-CCD EOS Clip
Exposure: 59 x 240s @ ISO 800 (3hr. 56min.)
Acquisition: ImagesPlus 3.82 Camera Control
Processing: ImagesPlus 3.80a – Calibrated, registered, averaged, DDP
Post-processing: Adobe Photoshop CS4; Gradient XTerminator; Noise Ninja, Noel Carboni's Tools
Date(s): February 19, 2010
Temperature(s): 42ºF (dropped to 37ºF)
SQM reading (begin - end): 18.85 - cloudy skies