Image by Danny Flippo
M2 has a diameter of about 140 light-years, contains about 150,000 stars, and is one of the richer and more compact globular clusters, as its classification in density class II indicates. This cluster is of notable ellipticity (ellipticity 9, or form E1), as can be noted in our photograph; it is extended in position angle 135 deg. At about 37,500 light years (according to W.E. Harris' database), it lies well beyond the Galactic Center. Visually it is of apparent magnitude 6.5 and about 6 to 8 minutes of arc in diameter, with a bright, compressed central region of about 5'. Photos reveal that it extends out to a diameter of 12.9 arc minutes. Its brightest stars are red and yellow giants of magnitude 13.1, while its horizontal branch stars have an apparent brightness of 16.1. The cluster's overall spectral type has been given with F0, its color index as -0.06.
