Messier 81 (M81)

Common Name: Bode's Galaxy

Also Known as: NGC 3031

Object Type: Grand Design Spiral Galaxy

Constellation: Ursa major

Distance from Earth: 11.8 million light years

Apparent Magnitude: 6.94

Coordinates: RA 09H 55M 33.2S DEC 69 deg 03 min 55 sec

Actual Size: 92,000 light years in diameter

Apparent Dimensions: 26.9 arc-minutes x 14.1 arc-minutes

Discovered by: M81 was independently discovered by Johann Gottfried Koehler in 1774. He described it as a "nebulous patch", this one about 3⁄4 degree away from the other, "very pale and of elongated shape". Koehler described M81 and M82 as ‘two nebulous stars at the ear of the Great Bear’.
Bode’s Galaxy was named after Johann Elert Bode, the German astronomer who discovered it on December 31, 1774, along with the nearby Cigar Galaxy. He described the pair as “two small nebulae 3/4 degrees separated", In 1779, Pierre Méchain independently rediscovered both objects and reported them to Charles Messier, who added them to his catalog.

Description: With prominent, clearly defined spiral arms, Bode’s Galaxy is an excellent example of a grand design spiral.
Messier 81 is the largest member of the M81 Group of galaxies, a group that contains 34 galaxies located in Ursa Major. The M81 Group includes the Cigar Galaxy (Messier 82) and NGC 3077, two galaxies that are strongly affected by their large neighbor. The gravitational influence of M81 has left all three galaxies stripped of hydrogen gas. The interactions between the galaxies have allowed interstellar gas to fall into the central regions of Bode’s Galaxy and NGC 3077, which has triggered vigorous starburst activity there. Several other members of the M81 Group, including the Cigar Galaxy (M82), are located in the same region of the sky. The Cigar Galaxy can be seen 38 arc minutes north of M81.
The two galaxies can easily be seen in binoculars and small telescopes, but are not visible to the naked eye. M82 is smaller and fainter than M81, but is a wonderful example of a starburst galaxy and the two make a popular pair among astronomers.
The M81 Galaxy Group contains 34 galaxies. Several members of the M81 group, including M82, are located in the same region.
M81 is the largest member of the group and its gravitational influence have strongly affected its neighbors.
The galaxy’s size and proximity – it is one of the nearest galaxies beyond the Local Group – often make it a target of study by professional astronomers, while amateur astronomers and astrophotographers like to observe the galaxy because it is large and has a relatively high brightness.
M81 contains 250 billion stars.
M81 has 2 well defined spiral arms that contain large quantities of stellar dust associated with numerous starburst regions.

Click Below Image(s) for Full Size:

It can easily be seen in binoculars, which only show a dim patch of light, and is best viewed in larger telescopes, which reveal details of the galaxy’s spiral structure.
3-inch telescopes show M81 as a hazy, bright oval-shaped patch of light, while 6-inch telescopes reveal the galaxy’s bright core surrounded by a faint halo.

The best time to observe M81 is in the spring months.

Platesolve

M81 Spiral Galaxy (ZWO ASI2600 one-shot color camera)

Imaging Details

M81 Spiral Galaxy (ZWO ASI2600 monochrome camera & Baader LRGB filters)

Imaging Details
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