M15; Pegasus 
Astro-Physics 305mm f/3.8 Riccardi-Honders astrograph 
KAF-16803 FLI Proline 
Total Exposure Time: 4.2 hours LRGB 100:50:50:50 minutes, RGB 2x2 
October 2012; Inkom, ID 
Comments: M15 is about 33,600 light-years from Earth, and 175 light years in diameter. It has an absolute magnitude of -9.2, which translates to a total luminosity of 360,000 times that of the Sun. Messier 15 is one of the most densely packed globulars known in the Milky Way galaxy. Its core has undergone a contraction known as 'core collapse' and it has a central density cusp with an enormous number of stars surrounding what may be a central black hole. Home to over 100,000 stars, the cluster is notable for containing a large number of variable stars (112) and pulsars (8), including one double neutron star system, M15 C.Ref   An old image of M15 may be seen here.