M82 - The "Cigar" Galaxy in Ursa Major

M82 AP155 ST10XME

M82 - Galaxy in Ursa Major
Mag 6.9 RA 9:55.8 Dec +69 41


Discovered by Johann Elert Bode in 1774.

Messier 82 (M82, NGC 3034) is a remarkable galaxy of peculiar type in constellation Ursa Major. It is usually classified as irregular, though probably a distorted disk galaxy, and famous for its heavy star-forming activity, thus a prototype member of the class of starbursting galaxies.

This galaxy is the prototype of an irregular of the second type, i.e. a "disk" irregular. Its core seems to have suffered dramatically from a semi-recent close encounter with M81, being in a heavy starburst and displaying conspicuous dark lanes. This turbulent explosive gas flow is also a strong source of radio noise.

Recently, over 100 freshly-formed (young) globular clusters have been discovered with the Hubble Space Telescope. Their formation is probably another effect triggered by the encounter with M81. It was estimated that the most recent tidal encounter occurred between about 50 and several 100 million years ago: STScI's most recent number was 600 million years, when the 100-million-year-long period of heavier interaction began.

As a member of the M81 group, M82 is 12 million light years distant.

ST-10XME and CFW8a Astrodon LRGB
AP155EDF on AP900GTO
Luminance 23 x 5 min
RGB 4 x 10 min
Images acquired w CCDSoft5
Darks and Flats in CCDSoft5
Alignment and combines in Maxim
Colour combines, Levels and Curves in PS CS4
Some High Pass Filtering applied in PS CS4
Image is cropped slightly.

Flesherton, Ontario, Canada
March 15th, 2009
Ambient temp 0C; camera temp -20C; No Moon