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Астронет: Астрономическая картинка дня Мессье 81 http://www.variable-stars.ru/db/msg/1729591/eng |
Credit & Copyright: Wissam Ayoub
Explanation:
One of the brightest galaxies in planet Earth's sky is similar in size
to our Milky Way Galaxy: big,
beautiful
Messier 81.
Also known as NGC 3031 or Bode's galaxy for its 18th century discoverer,
this grand spiral
can be found toward the northern constellation of Ursa Major, the Great Bear.
The sharp,
detailed telescopic view reveals M81's bright yellow nucleus, blue
spiral arms, pinkish starforming regions, and sweeping
cosmic dust lanes.
Some dust lanes actually run through the galactic disk (left of center),
contrary to other prominent
spiral features though.
The errant dust lanes may be the lingering
result of a close encounter between
M81 and the nearby galaxy M82 lurking outside of this frame.
M81's faint, dwarf irregular satellite galaxy, Holmberg IX,
can be seen just below the large spiral.
Scrutiny of variable stars in M81 has yielded a
well-determined distance
for an external galaxy -- 11.8 million light-years.
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.