F or the last two months, I've been featuring galaxies in my astronomy column. This is not surprising since springtime is the best time of year to view most of the brightest galaxies in the night sky.
This grand design spiral is named Bode's Galaxy after the astronomer Johann Elert Bode, who discovered it on Dec. 31, 1774. It is also more commonly known as M81 in Charles Messier's list of 110 deep space objects he avoided because they weren't comets - the astronomical quarry he was seeking.
M81 is the largest member of a group of 34 galaxies called the M81 Group. This group is also gravitationally connected to our local group of galaxies which includes the Milky Way (us), Andromeda and the Pinwheel galaxy. Together, we make up part of the Virgo Super Cluster, which at 110 million light years wide forms just one tiny strand of the seemingly endless filamentary structure of the known universe.
The peculiar feature about Bode's Galaxy (M81) is the presence of at least five short parallel dust lanes that don't line up with the dust lanes in its sweeping spiral arms (see area to the upper right of the galactic core). Some astrophysicists speculate that this could be the result of a close encounter in the past with M81's relatively close by companion, M82, the Cigar Galaxy.
I prefer a more whimsical explanation. M81 is located in the constellation Ursa Major The Big Bear. Perhaps this mythical bear took a swipe at M81 and we see its claw marks raking across the galactic disk!
Gary Zientara is resident astronomer and owner of Mount Sangre Observatory.