Discovered by Charles Messier in 1779.
M56 is located about half-way between Beta Cygni (Albireo) and Gamma
Lyrae. It is one of the less bright Messier globulars, especially
lacking the bright core which most globulars have. Nevertheless it is
not too difficult to resolve, even at its rather large distance. At its
distance of 32,900 light-years. its diameter of 8.8 arc minutes
corresponds to a linear extension of about 85 light years. Visually,
only about the inner third of this great ball, of about 3' diameter is
visible.
This stellar swarm is approaching us at the high velocity of 145 km/sec.
M56 was one of Charles Messier's original discoveries; he saw it first on January 23, 1779 and describes it as a "nebula without stars," like most globular clusters. It was first resolved into stars by William Herschel around 1784.
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