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Астронет: Астрономическая картинка дня Яркая галактика M81 http://variable-stars.ru/db/msg/1177445/eng |
Credit & Copyright: Robert Gendler
Explanation:
Big and beautiful
spiral galaxy M81,
in the northern constellation
Ursa Major,
is one of the
brightest
galaxies visible in the skies of
planet Earth.
This superbly
detailed view
reveals its bright nucleus, grand
spiral arms and sweeping cosmic dust lanes with a scale
comparable to
the Milky Way.
Hinting at a disorderly past,
a remarkable dust lane runs straight through the
disk, below and right 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 (aka NGC 3031)
has yielded one of the best
determined
distances 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.