Messier 13 Hercules Cluster
Messier 13, the Hercules Globular Cluster, is a globular cluster of about 300 000 stars and is almost 150 light-years across. Like other globular clusters, it is in orbit around our Milky Way galaxy, and is about 25,100 light-years away from us. It is one of the most famous of this class of object and is a glorious sight in the telescope, looking like a pile of diamonds on black velvet.
Where it is in the sky:
Visible in the summer and early autumn skies, the "keystone" shape in the central part of the constellation Hercules is easily found, not far from the bright star Vega. M13 is about one third of the way down the right hand side and, while faint, it is plainly visible to the naked eye from a dark site.
Acquisition Details:
Camera: QSI 583wsg
Guide-camera: Starlight-Express LodeStar
Telescope: Officina Stellare Ultra-Corrected RC360
Mount: Paramount ME II
Image scale: 0.56 arcsec/pixel
Total exposure: 1.8 hours