Messier 15

Messier 15 (also known as NGC 7078 ) is a 6.2 like bright globular clusters with an angular extent of 18 ' in the constellation Pegasus. Its distance is about 30,000 light-years. The brightest of his least 500,000 members reach an apparent magnitude of 12.6 mag. The star cluster was discovered in 1746 by Jean -Dominique Maraldi and described as nebulous star. Charles Messier (1764 ) and Johann Elert Bode could perceive no stars in the interior, which in 1783 William Herschel succeeded.

In amateur telescopes M15 appears visually only about 7 ' tall, photographically about 12 '. The " tidal radius" on the other hand, outside of which the gravity of the Milky Way star leaves drift is 21 ' to 22 ' ( about 210 light-years ).

Messier 15 is the first globular clusters in which a planetary nebula was discovered: 1928 Pease 1 It also contains nine pulsars - supernova remnants from the time when M15 was still young. He is also (in addition to Messier 3 and Omega Centauri ) to the globular clusters with the most variable stars; so far we have identified 112.