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Астронет: Астрономическая картинка дня Leo A: Близкая карликовая неправильная галактика http://variable-stars.ru/db/msg/1201143/eng |
Credit & Copyright: V. Vansevicius (IoP Lithuania),
N. Arimoto (NAOJ)
et
al.,
Suprime-Cam,
Subaru Telescope,
NAOJ
Explanation:
Why isn't this small galaxy simple?
The above image and contemporary observations of small nearby galaxy Leo A were
supposed to show it has a simple structure.
Now Leo A is known to be a
dwarf irregular galaxy - one of the most common types of
galaxies in the universe and a type that is likely a
building block
of more massive galaxy like our
Milky Way Galaxy.
In general, larger galaxies have
recently been shown to continually eat,
and be primarily composed of, many of the
smaller satellite galaxies that have surrounded them.
Leo A's surprising complexity indicates that that it,
and possibly many
small galaxies, have formation histories
nearly as complex as large galaxies.
Leo A spans about 10,000
light years and lies about 2.5 million
light years away toward the constellation of
Leo.
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.