Messier 22

Messier 22 (also known as NGC 6656 ) is a 5.5 like bright globular clusters with a surface area of 32 ' in the constellation Sagittarius. He stands in the direction of the Milky Way center, 2 degrees north of the star Lambda Sagittarii.

M22 is the brightest visible from Europe globular clusters, however, is low in the southern sky. Visible to the naked eye as a star- like object in the telescope he is an attractive deep sky object and almost as gorgeous as the famous Hercules Cluster M13. It consists of about 80,000 stars, among which about 100 are cataloged as variable stars.

Due to its brightness M22 ​​was also observed as the first globular clusters: the German amateur astronomer Johann Abraham Ihle took him on 26 August 1665 in his 2-inch telescope as a round patch of fog true. In the eight- inch model will be of the brightest stars (11 mag) a few dozen at the pile edge recognizable. 2001 observed one outbursts, which were explained by a dwarf nova or by micro- lensing close stellar orbits.

In September 2012, discovered by an international research team using the Very Large Array of the U.S. Radio Astronomy Observatory NRAO that M22 contains more than a black hole, what had previously been on the grounds of celestial mechanics as excluded. The two objects each have 10 to 20 solar masses.