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 deep, wide-field image also reveals distant background galaxies
including NGC 6207 at the upper left, and faint, foreground
Milky Way dust clouds known
to some as integrated flux nebulae.
Source: https://apod.nasa.gov/apod/ap240926.html
