Messier 37 (also M37, NGC 2099, Mel 38, Cr 75 and OCL 451) is a magnitude +6.2 open star cluster located 4,511 light-years away in the constellation Auriga.
The cluster (along with M36 and M38) was discovered by by Italian astronomer Giovanni Battista Hodierna with probably a 1-inch 20x Galilean refracting telescope in the castle of his patron Carlo Tomasi et Caro, in Palma di Montechiaro sometime before 1654. The cluster was independently discovered by French astronomer Charles Messier on the 2nd September 1764.
Right Ascension 05h 52m 18s, Declination +32° 33' 02"
M37 is located in the antipodal direction, opposite from the Galactic Center as seen from Earth. Estimates of its age range from 347 million to 550 million years. It has 1,500 times the mass of the Sun and contains over 500 identified stars, with roughly 150 stars brighter than magnitude 12.5. M37 has at least a dozen red giants and its hottest surviving main sequence star is of stellar classification B9 V. The abundance of elements other than hydrogen and helium, what astronomers term metallicity, is similar to, if not slightly higher than, the abundance in the Sun Read more