Degree of difficulty 3 (of 5)

Minimum aperture 50mm

Designation NGC 6779

Type Globular cluster

Class X

Distance 27,390 ly (2003)

Size 55 ly

Constellation Lyra

R.A. 19h 16.6min

Decl. +30° 11′

Magnitude 8.4

Surface brightness –

Apparent diameter 7′

Discoverer Messier, 1779

History Charles Messier found M 56 on the 19th of March 1779, on the same night that he made an independent discovery of a comet, which had been previously found by Bode without his knowledge. On the 23rd, when he finally reobserved M 56 to measure its position, he noted: “nebula without star, has little light, near to it is a star of 10th magnitude.” Five years later in 1784, John Herschel succeeded in resolving this globular cluster into individual stars, thereby proving Messier's note wrong. Herschel described M 56 as a “fine compressed cluster, round, inclining to triangular form, brighter towards the middle, stars of 12th to 14th magnitude.”

Observing with an 11-inch refractor, d'Arrest noted: “A star cluster, which contains a large number of stars, none of which is brighter than 12th to 13th magnitude. With 356× magnification resolved into minute stars.” Reverend Webb even thought he had resolved M 56 with his very modest 3.7-inch refractor.

Curtis'description of the photographic appearance reads: “Rather bright, condensed cluster, 3' in diameter. Probably globular.”

Astrophysics M 56 is a poorly concentrated globular cluster of the Shapley class X. Only M 55 and M 71 are even less concentrated. Shapley was the first to notice the slightly elliptical shape of M 56 in PA 45°.

Its very eccentric, but low-inclination, orbit around the galactic center takes M56 out to distances of 40,000 light-years. But then, 125 mil lion years later, it gets as close as just a few thousand lightyears to the galactic core. The current distance of M 56 from us is 27,000 light-years, as it passes through the outer half of its orbit.