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Астронет: Астрономическая картинка дня Шаровое скопление M5 http://www.variable-stars.ru/db/msg/1161939/eng |
Credit & Copyright: Anglo-Australian Telescope
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Explanation:
The globular cluster
M5, pictured above, contains
roughly 100,000 stars.
These stars formed together and are gravitationally bound. Stars orbit the
center of the cluster, and the cluster orbits the center of our Galaxy. So
far, about 160
globular clusters
are known to exist in a roughly spherical halo around the
Galactic center.
Globular clusters
do not appear spherically distributed as viewed from the Earth, and this
fact was a key point in the determination that our
Sun is
not at the center of our
Galaxy. Globular clusters are very old. There is a straightforward
method
of determining their age, and this provides a very interesting lower limit
on the age of our universe of about 14 billion 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.