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Астронет: Астрономическая картинка дня M13: огромное шаровое скопление в Геркулесе http://variable-stars.ru/db/msg/1843653/eng |
Credit & Copyright: Joan Josep Isach Cogollos
Explanation:
In
1716, English astronomer
Edmond Halley noted,
"This is but a little Patch, but it shows itself to the naked Eye, when
the Sky is serene and the Moon absent."
Of course, M13
is now less modestly recognized as the Great Globular Cluster in
Hercules, one of the brightest
globular
star clusters in the northern sky.
Sharp telescopic views like this one
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.
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.
The remarkable range of brightness
recorded in this image
follows stars into the dense cluster core.
Distant background galaxies in the medium-wide field of view
include NGC 6207 at the upper left.
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.