Open cluster M52 is one of the original discoveries of Charles Messier, who cataloged it on September 7, 1774 when the comet of that year came close to it.

M52 is a fine open cluster located in a rich Milky Way field. Astronomers found 193 probable members in a region of 9' radius, and the density near the center is about 3 stars per cubic parsec.

The brightest main sequence star of this cluster is of mag 11.0 and spectral type B7. Two yellow giants are brighter: The brightest is of spectral type F9 and mag 7.77, the other of type G8 and mag 8.22. The Sky Catalogue 2000.0 gives an age of only 35 million years, which coincides with the value given by Woldemar Götz, who mentions that this cluster contains one peculiar Of star, i.e. an extremely hot star with peculiar spectral lines of ionized helium and nitrogen.

The distance of this cluster is not very well known, it's estimadet between 3,000 and 7,000 ly.This uncertainty is mainly due to the high interstellar absorption its light has suffered on its way to us, which is complicated to estimate reasonably.

Amateurs can see M52 as a nebulous patch in good binoculars or finder scopes. In 4-inch telescopes, it appears as a fine, rich compressed cluster of faint stars, often described as of fan or "V" shape; the bright yellow star is to the SW edge.

M52 can be found quite easily by extending the line from Alpha over Beta Cassiopeiae by 6 1/2 degrees to the NW to 5th mag 4 Cassiopeiae; M52 is roughly 1 degree south and slightly west of this star.