M81 (Bode’s Galaxy) & M82 (Cigar Galaxy)

OTA: Star-Fire 175 (f/8)

Camera: FLI - PL16070AE

Observatory: Deep Sky West

EXPOSURES:

Red: 25 x 900 sec.

Blue: 30 x 900

Green: 29 x 900

Lum.: 18 x 900

Total exposure 25.5 hours

Image Width: ~1.4 deg

Processed by Alex Woronow using PixInsight, StarNet++, Aurora HDR in 2019

Messier 81 (aka Bode’s Nebula) is the largest galaxy in the “M 81 group” of 34 galaxies located in the constellation Ursa Major. At approximately 11.7 light-years from the Earth, it makes this group a member of the Local Group, which also contains our Milky Way Galaxy. In turn, the Local Group is within the Virgo Supercluster. Both M 81 and M 82 were discovered by the German astronomer Johann Elert Bode on December 31, 1774 and independently by Johann Gottfried Koehler around the same time.

Gravitational interactions of M 81 with M 82 (aka Cigar Nebula) have allowed interstellar gas and dust to fall into the centers of M 82, leading to vigorous star formation known as “starburst.”

M 81 contains a 70 million solar mass “super massive” black hole at its center. The blue hues in the image are young bright stars. The red hues are gas and dust clouds that largely owe their color to ionized hydrogen. The young blue stars contribute greatly to the ionization of the hydrogen.

M 82, with its impressive starburst (red streamers) is a major radio-frequency emitter and the brightest infrared source in the sky. Like M 81, M 82 has a super massive black hole at its center, “weighing in” at about 30 million solar masses. (Black holes commonly lie in galactic centers.)

M 81, M 82, and more than 50 other galaxies lie behind a diffuse cloud in our own galaxy and known as the IFN (Integrated Flux Nebula), which casts a thin veil over most of our northern-most sky. It is lit not as by reflection of local star light, but by the integrated glow of the Milky Way. The IFN is composed of dust, hydrogen, carbon dioxide and many other chemical constituents, as are most interstellar clouds. One of the interesting components of the dust is the Polycyclic Aromatic Hydrocarbons (PAHs), which are organic hydrocarbons that can result from the incomplete combustion of organic materials. Not too surprisingly, PAHs have been tagged as a possible progenitor of early forms of life.

(Source: largely Wikipedia & messier-objects.com)