M81 and M82 Galaxies

Messier 81 (also known as NGC3031 and Bode's Galaxy), the largest of the two in the image below, is a spiral galaxy about 12 million light years away, with a diameter of 90,000 light years, in the constellation Ursa Major.

The smaller galaxy is Messier 82 (also known as NGC3034 and the Cigar Galaxy) is a starburst galaxy approximately 12 million light years away. A starburst galaxy is undergoing an exceptionally high rate of star formation.

The faint blue patch below M81 is Holmberg IX, a dwarf irregular galaxy and a satellite of M81. It is believed to have formed within the last 200 million years, making it the youngest nearby galaxy.


Exposure
 • 14¾ hours (88 x 10 minutes) @ -20°C
 • Dusk flats
 • Camera position angle: 300°
Processing  • With PixInsight:
   ☞ Calibrate, star-align, and integrate subframes
   ☞ Background neutralization
   ☞ Process for high-dynamic range
 • Noise reduction with Topaz DeNoise AI
 • Final tweaking in Photoshop CS6
Date and Location  • 2020: February 21 & 22
 • 2021: March 5 & 6
 • Louisa County, Virginia, USA
Equipment
 • TMB-130SS APO refractor @ f/7 on an A-P 1200 mount
 • ZWO ASI-1600MC Pro color camera
 • Guided with an ST-402 camera on a 60mm f/5 scope
 • Imaging and autoguiding with MaxIm DL 6.20
 • Automated image acquisition with ACP Observatory Control


Updated May 23, 2023