M37
Open cluster in Auriga

10.1″ f/4.5, Mallincam DS432cTEC with 0.5 focal reducer
Exposure = 5 sec, Live Stacked frames = 20, Gain = 40 of 250

M37 is a beautiful large, compressed star cluster that looks almost like a loose globular cluster (see M4 for comparison). Burnham’s says it “contains about 150 stars down to magnitude 12.5; the total population may be in excess of 500 stars”. Both Burnham’s and O’Meara refer to a ruby or topaz coloured bright 9.5 magnitude star near the cluster center. – can you see it in the image above?

M37 is significantly older than it’s sibling, M36, listed at approximately 350 to 550 million years old. The cluster spans about 15 arc minutes, is about 25 light years across in actuality, and similar to M36 is 4500 light years away.

North at 1 o’clock, East at 10 o’clock