|Observation data (J2000.0 epoch)|
|Right ascension||07h 41.8m|
|Distance||5.4 kly (1.7 kPc)|
|Apparent magnitude (V)||6.1|
|Apparent dimensions (V)||27.0′|
|Estimated age||300 million years|
planetary nebula NGC 2438
|Other designations||NGC 2437|
Messier 46 (also known as M 46 or NGC 2437) is an open cluster in the constellation of Puppis. It was discovered by Charles Messier in 1771. Dreyer described it as "very bright, very rich, very large." M46 is about 5,500 light-years away. There are an estimated 500 stars in the cluster, and it is thought to be some 300 million years old.
The planetary nebula NGC 2438 appears to lie within the cluster near its northern edge (the faint smudge at the top center of the image), but it is most likely unrelated since it does not share the cluster's radial velocity. It is an example of a superimposed pair possibly similar to that of NGC 2818.
M46 is located close by to another open cluster, Messier 47. M46 is about a degree east of M47 in the sky, so the two fit well in a binocular or wide-angle telescope field.
- Majaess D. J.; Turner D.; Lane D. (2007). "In Search of Possible Associations between Planetary Nebulae and Open Clusters".
- "The hot blue stars of messier 47". ScienceDaily. 17 December 2014.
- Kiss, L. L; Szabó, Gy. M; Balog, Z; Parker, Q. A; et al. (2008). "AAOmega radial velocities rule out current membership of the planetary nebula NGC 2438 in the open cluster M46".
- Mermilliod, J.-C; Clariá, J. J; Andersen, J; Piatti, A. E; et al. (2001). "Red giants in open clusters. IX. NGC 2324, 2818, 3960 and 6259".
- Messier 46, SEDS Messier pages
- Waid ObseratoryMessier 46, Amateur Astronomer Image –
- Dark Atmospheres Photography – M46 w/ NGC 2438 detail
- Messier 46 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images