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. While the NGC mentions "stars of 11th to 14th magnitude", more modern measurements have shown that the brightest stars in this cluster are of about 13th magnitude.
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.
This globular cluster lies in a nice low-power Milky Way field.