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Астронет: Астрономическая картинка дня Яркая спиральная галактика M81 http://variable-stars.ru/db/msg/1345966/eng |
Credit & Copyright: Ken Crawford
(Rancho Del Sol
Observatory)
Explanation:
One of the brightest galaxies in planet Earth's sky is similar in size
to our Milky Way Galaxy:
big, beautiful M81.
The grand spiral galaxy can be found toward the northern constellation
of the Great Bear
(Ursa Major).
This superbly
detailed image reveals M81's bright yellow nucleus, blue
spiral arms, tell tale pinkish star forming regions, 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 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.
M81's dwarf companion galaxy
Holmberg IX
can be seen just above the
large spiral.
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
Specific
rights apply.
A service of:
LHEA at
NASA /
GSFC
& Michigan Tech. U.