Open Cluster Messier 37

Object Description

Messier 37
Messier 37: Open cluster in Auriga; 500 mm Cassegrain 3625 mm f/7.2; SBIG STL11K; 10+10+10+10 min LRGB; Bernese Highlands; © 2009 Radek Chromik

M 37 (NGC 2099) is the most beautiful of the three bright Messier star clusters in the constellation Auriga (Fuhrmann). The other two are M 36 and M 38. It was first found in 1654 by Giovanni Hodierna and then rediscovered on September 2, 1764 by Charles Messier. Messier wrote: «Cluster of small stars, not far from the previous one, on the parallel of χ Aurigae; the stars are smaller, closer together, and contain nebulae; It is difficult to see the stars with an ordinary 3.5-foot telescope: this cluster is inscribed on the map of the second comet from 1771, Mem. Akad. 1777.» [281]

The star cluster contains about 150 stars up to 12.5 magnitudes. In total, it should have more than 500 stars. The stellar population differs from that of M 36 and is believed to be older. The age is estimated to be just over 200 million years. The youngest stars are of type B9V and most of the other bright stars are main sequence A stars. The cluster also contains at least a dozen red giants. The brightest of these is 9.5 mag bright and stands out near the center like a red ruby ​​in a field of diamonds. The distance of the star cluster is at 1383 pc to 1400 pc, slightly more than M 36. [4, 145, 196]

«Revised New General Catalogue and Index Catalogue» Dr. Wolfgang Steinicke, 2021 [277]
DesignationNGC 2099
TypeOCL (II1r)
Right Ascension05h 52m 18.3s
Declination+32° 33' 11"
Diameter15.00 arcmin
Visual magnitude5.6 mag
Dreyer DescriptionCl, Ri, pCM, st L & S
IdentificationM 37, OCL 451

Finder Chart

The open star cluster is located east of the pentagon in the constellation Auriga (Charioteer) and is visible to the naked eye on a dark night. The best observation time is September to April.

Chart Messier 37
Chart created using SkySafari 6 Pro and STScI Digitized Sky Survey. [149, 160]


4«Burnham's Celestial Handbook: An Observer's Guide to the Universe Beyond the Solar System» by Robert Burnham; Dover Publications, Inc.; Voume I: ISBN 0-486-23567-X; Volume II: ISBN 0-486-23568-8; Volume III: ISBN 0-486-23673-0
145SIMBAD astronomical database;
149SkySafari 6 Pro, Simulation Curriculum;
160The STScI Digitized Sky Survey;
196Celestial Atlas by Curtney Seligman; (2020-12-28)
277«Historische Deep-Sky Kataloge» von Dr. Wolfgang Steinicke; (2021-02-17)
281«Catalogue Nébuleuses et des Amas D'Étoiles» Observées à Paris, par M. Messier, à l'Observatoire de la Marine, hôtel de Clugni, rue des Mathurins. «Connoissance des temps ou connoissance des mouvements célestes, pour l'année bissextile 1784 » Page 227; (2021-02-21)