The object Messier 73 is a little conspicuous assortment of four stars of 10th to 12th magnitude, situated in the very western part of constellation Aquarius; its nature as a physical group is doubtful. It lies only about 1.5 deg east of globular cluster M72.

It was discovered by Charles Messier in 1780.

He descibe it as: "Cluster of three or four small stars, which resembles a nebula at first glance, containing very little nebulosity; this cluster is located on the parallel [of declination] of the preceding [M 72]; its position has been determined from the same star [Nu Aquarii]."

This "Y"-shaped group of stars is well visible in 4-inch telescopes; the fourth star is notably fainter and difficult in these instruments. It is best found from M72 which is almost at the same declination (very slightly North) and 1.5 deg West. The 4.5-mag star Nu Aquarii, mentioned by Messier, is about 2deg North and 1.5 deg to the West. East of this star (and not far from M73), the Saturn Nebula (NGC 7009) can be found.