M53 - NGC 5024

Messier 53 (NGC 5024) is a globular cluster located approximately 58,000 light-years from Earth in the constellation Coma Berenices, making it one of the more distant globular clusters in the Messier catalog. Discovered by Johann Elert Bode in 1775 and independently cataloged by Charles Messier in 1777, M53 is also notable for being about 60,000 light-years from the galactic center, placing it in the outer halo of the Milky Way. The cluster contains an estimated 250,000 stars packed into a volume roughly 220 light-years in diameter. M53 is relatively metal-poor, meaning its stars formed from gas that had not been significantly enriched by previous generations of stellar nucleosynthesis. This is consistent with its great age, estimated at approximately 12.7 billion years, making it one of the older globular clusters known. The cluster has a moderately concentrated core and contains a significant population of blue straggler stars, which are stars that appear younger and bluer than they should be given the cluster's age, likely formed through stellar mergers or mass transfer in binary systems. In amateur telescopes, M53 appears as a bright, round fuzzy ball that begins to resolve into individual stars at around 6 inches of aperture. It lies about 1 degree northeast of the star Diadem (Alpha Comae Berenices), making it relatively easy to locate. About 1 degree to the southeast lies the much fainter and looser globular cluster NGC 5053, and the two make an interesting contrast when observed together.

M53 contains roughly 250,000 stars within a diameter of about 220 light-years and lies approximately 58,000 light-years from Earth.