The beautiful cluster M 15 is not one of the brightest or one of the largest globular clusters in the sky, but the bright star SAO 107195 makes for a brilliant companion in the field of view of my 8" telescope. The cluster is not overly large, so I decided to go for the full focal length of 1624 mm because the air was remarkably steady in this late summer night. Of course the apparent proximity of these two bright objects in the field of view is just an illusion. The star is only 400 light years from our solar system, but the cluster is circling around our galaxy's center in a distance of 34000 light yeras from here. The considerably wide distance similar to M56 tells us that this cluster is obviously one of the larger representatives of this class of objects.

M 15 has two peculiarities. First, it contains a tiny planetary nebula, the remnant of a dying star blowing its atmosphere into space. At double resolution I was barely able to identify the tiny blueish smudge on my picture where the object is expected to be, but confirmation is definitely reserved for professional imaging like the Hubble space telescope. The second thing noteworthy about M 15 is the fact that it contains a medium-sized black hole of about 4000 times the mass of our sun. This class of exotic objects - much heavier than those originating from star collapses but much lighter than the supermassive black holes in the center of galaxies - were often hypothesized, but confirmed not earlier than some 20 years ago.