M37, An open cluster - this image cropped and reduced from the original photo

High above Orion, near the zenith and within the swath of the Milky way, are three nice open clusters M36, M37, & M38. M37 is the lower left of the three. It's about 4400 light years away and spread over about 24 light years in width. M37 has the most stars of the 3, containing about 150 brighter than mag 12.5, and perhaps a total of over 500.  It's a little older than many open clusters, at about 300 million years. As a result, there are a number of red giants (slightly off white here) that have developed and stand out from the rest. Visually it has an overall magnitude of 6.2 and is about 24 arc minutes in extent.

10" F6.3 Schmidt Cassegrain Telescope, (1600mm F.L.) Modified Canon 400D camera using a Baader coma corrector and IR-UV filter, placed at the scope's prime focus
8 photos aligned and averaged together, then brightness, color, and contrast enhanced.
Click on photo above for a full frame full rez image.
Each photo, 120 seconds exposure at ISO 1600