Messier 37, also cataloged as NGC 2099, is the brightest and richest of the three famous open clusters in Auriga and a rewarding target for astrophotographers of all levels. Spanning roughly 19′ across the sky, it fits comfortably into the field of view of most telescopes paired with common camera sensors, making framing straightforward. With its dense scattering of stars set against the Milky Way, it delivers a colorful, star-packed image that benefits from moderate exposure times to preserve the brighter members without clipping. RGB imaging is particularly effective here, revealing subtle color contrasts between the cluster’s warmer and cooler stars.
Names and Catalog numbers
- M 37 (Messier 37)
- NGC 2099
- Mel 38 (Melotte 38)
Position and the cosmic neighborhood
Messier 37 sits in the constellation Auriga at a right ascension of 05h 52m 17.8s and a declination of +32° 32′ 42″, placing it in one of the richest regions of the northern winter Milky Way. It is the easternmost and most impressive of Auriga’s trio of Messier open clusters, sharing this stretch of sky with its neighbors Messier 36 and Messier 38 nearby. For imagers, the surrounding star fields provide a densely populated backdrop that lends depth and context to wide-field compositions. High in the sky for northern observers during winter, it stays well placed for long imaging sessions with minimal atmospheric interference.
Nice to Know
- Messier 37 is the richest of the three Auriga open clusters, offering the most star-packed target of the group for astrophotography.
- It lies roughly 4,570 light-years from Earth, yet its bright members make it accessible even to modest imaging setups.
- The cluster spans a physical diameter of about 26 light-years, appearing 19′ wide in the sky — an ideal size for many telescope and camera combinations.
- Carrying three designations — Mel 38, Messier 37 and NGC 2099 — it is a well-documented and frequently photographed winter showpiece.
Brightness, distance and size
It lies about 4,570 light-years from Earth and spans roughly 26 light-years across. On the sky it appears about 19′ in size.
