Great Puppis Cluster
- Pierre Moutounet-Cartan
- Mar 4
- 1 min read
#Messier46, #NGC2437, and #PMC33
About this object
Messier 46 (M46), also known as NGC 2437, is a magnificent open cluster located in the constellation Puppis, offering amateur astronomers a rich and rewarding observing experience. Discovered by Charles Messier in 1771, this cluster is approximately 5,000 light-years away and contains an estimated 500 stars, with a combined mass of about 453 times that of the Sun. Spanning a broad tidal radius of 37.8 light-years and a core radius of 8.5 light-years, M46 is a large and densely populated cluster, with an estimated age of 251 million years. Interestingly, the cluster appears more extended in infrared light than in visible light, suggesting mass segregation, where fainter, redder stars are migrating to the outer regions, possibly forming a tidal tail due to past gravitational interactions. One of the most intriguing features of M46 is the planetary nebula NGC 2438, which appears to lie within the cluster near its northern edge. However, this is a line-of-sight coincidence, as NGC 2438 does not share the cluster’s radial velocity and is likely a foreground object. On the other hand, the illuminating star of the bipolar Calabash Nebula is a confirmed member of M46, sharing its distance, radial velocity, and proper motion. With its mix of bright stars, subtle details, and the fascinating juxtaposition of NGC 2438, M46 is a must-see for stargazers exploring the wonders of the night sky.
Designations
Standardized Catalogues
PMC Observatory Catalogue
Photographs
