Messier 53 (also known as M53 or NGC 5024) is a globular cluster in the Coma Berenices constellation.

[8] Abundance measurements of cluster members on the red giant branch show that most are first-generation stars.

A tidal bridge-like structure appears to connect M53 with the close, very diffuse neighbor NGC 5053, as well as an envelope surrounding both clusters.

[10] In addition, M53 is a candidate member of the Sagittarius dwarf galaxy tidal stream.

Of these, a majority of 34 display behavior typical of the Blazhko effect, including 23 of type RRc – the largest known population of the latter in any globular cluster.