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Астронет: Астрономическая картинка дня Огромное шаровое скопление M13 в Геркулесе http://www.variable-stars.ru/db/msg/1245216/eng |
Credit & Copyright: Marco Burali, Tiziano Capecchi, Marco Mancini
(Osservatorio MTM)
Explanation:
In 1716,
English astronomer
Edmond Halley noted,
"This is but a little Patch, but it shews it self to the naked Eye, when
the Sky is serene and the Moon absent."
Of course, M13
is now modestly recognized as
the Great Globular Cluster in Hercules,
one of the brightest
globular
star clusters in the northern sky.
Telescopic views reveal the
spectacular cluster's hundreds of thousands
of stars.
At a distance of 25,000 light-years, the cluster stars
crowd
into a region 150 light-years in diameter, but
approaching the cluster core
upwards of 100 stars could be contained
in a cube just 3 light-years on a side.
For comparison, the
closest star to the Sun is over
4 light-years away.
Along with the cluster's dense core, the outer reaches of M13
are highlighted in this sharp
color
image.
The cluster's evolved red and blue
giant stars show up in yellowish and
blue tints.
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.