Messier 2

M2 was another accidental discovery for Charles Messier. He first observed it while looking for a comet in 1760. Unlike M1, credit for M2 is properly attributed to Jean-Dominique Miraldi II who noticed M2 in 1746 while observing a comet. Correctly, Miraldi suggested that this body might be a cluster. Telescopes of sufficient magnification and resolution to resolve the cluster's individual stars were not in use at the time. Miraldi could only guess that, as he could not detect any stars surrounding the apparent haze, the haze must be made up of stars too faint to be detected with the available equipment.

M2 contains 21 known variable stars, the brightest being Chèvremont's variable. Chèvremont's variable was first noted by A. Chèvremont in 1897. It can be seen on the eastern edge of the cluster, barely north of center, and varies in magnitude from 12.5 to 14 over a period of roughly 11 days (this period fluctuates). As the nearest noteworthy star in this section of the sky is a 10th-magnitude star ~5' NE of the nebula, M2 is the most visually impressive body in its section of the sky

Finding M2 in the autumn sky can be a little difficult. To begin, locate Epsilon Pegasi, the 2.4-magnitude nose of Pegasus. Then look to the southwest, roughly a fist-width extended at arms length, to find 3.9-magnitude Alpha Equulei. From the midpoint of these two stars, look 5° to the southeast to find a group of three 6th-magnitude stars. These are 25, 26, and 27 Aquarii. Look just south of 25 and 26 Aquarii, and you will see a string of binocular stars. Follow this string and you will find the 6th magnitude cluster, M2.

M2 can be easily observed at 23X magnification, and appears to have a bright, star-like center, surrounded by a yellow outer core. Then entire body seems to be surrounded by a light-blue halo. Under higher magnification, the halo, and then the core, will begin to resolve into a beautiful distribution that seems almost perfectly gaussian. All in all, M2 can be a delight for the amateur astronomer.