M 107 (NGC 6171) is
a globular cluster located in the contellation Ophiuchus. It was
discovered by Pierre Mechain in 1782. William Herschel independently
observed this cluster in 1793. Charles Messier later added this
object to his catalogue. It is the last globular cluster to appear
in his catalogue.
M 107 lies approximately
21,000 light years away and has a diameter of 80 light years. It
contains 100,000 stars, many of them being variable stars.
Globular clusters reside
in the halo around most galaxies. They contain some of the oldest