Open Cluster M37

Open Cluster M37 (also known as NGC 2099) is a rich open cluster in the Perseus Arm of the Milky Way.

M37 is roughly 300 million years old and contains over 500 stars with roughly 150 stars bright stars. M37 also contains at least a dozen red giants with the hottest main sequence star of spectral type B9V. It has a linear extension of about 20 to 25 light years. It is classified as Trumpler type I,1,r or I,2,r.