Bright Spiral Galaxy M81
From NASA’s Astronomy Picture of the Day
One of the brightest
galaxies in planet Earth's sky is similar in size to our Milky Way Galaxy:
big, beautiful M81.
This grand spiral galaxy
can be found toward the northern constellation of the Great Bear (Ursa Major).
This superbly detailed view reveals
M81's bright yellow nucleus, blue spiral arms, and sweeping cosmic dust lanes
with a scale comparable to the Milky Way.
Hinting at a disorderly
past, a remarkable dust lane actually runs straight through the disk, to the
left of the galactic center, contrary to M81's other prominent spiral
features.
The errant dust lane may be the
lingering result of a close
encounter between M81 and its smaller companion galaxy, M82. Scrutiny of variable
stars in M81 has
yielded one of the best determined distances for
an external galaxy -- 11.8 million light-years.
Image Credit: Subaru
Telescope (NAOJ), Hubble Space Telescope;
Processing & Copyright: Roberto Colombari & Robert Gendler
