M2 is about 55,000 light-years distant from Earth. At 175 light-years in diameter, it is one of the larger globular clusters known. The cluster is rich, compact, and significantly elliptical. It is 12.5 billion years old and one of the older globular clusters associated with the Milky Way galaxy. M2 contains about 150,000 stars, including 21 known variable stars. Its brightest stars are red and yellow giant stars. The overall spectral type is F4.
I (and others) use globular clusters as easy targets compatible with low integration time to keep the telescope 100% occupied, when waiting for a high priority target to rise.