M15

Messier 15 or M15 (also designated NGC 7078 and sometimes known as the Great Pegasus Cluster) is a globular cluster in the constellation Pegasus. At an estimated 12.5±1.3 billion years age, it is one of the oldest known globular clusters. M 15 is about 35,700 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. It also contains Pease 1, the first planetary nebula discovered within a globular cluster in 1928. Just three others have been found in globular clusters since then. Photographed with the RC8" reflector telescope and the ASI 2600MC color CMOS camera, August 27th, 2024 in Stuvsta. Exposure was 26*2 min with IDAS LPS P3 filter and postrocessing was done in Pixinsight with Blur Exterminator.