The absolute masses of 72 galactic clusters and 12 OB associations.

The Reddish (1978) relative masses for 72 open clusters and 12 OB associations are presently converted to absolute masses, within an error margin of about 25 percent, using three calibration clusters of known mass whose average mass is 300 solar masses. The Reddish technique assumes the initial stellar mass distribution function to be valid for all aggregates, together with a universal relationship between stellar mass and stellar luminosity.