Messier 46

Messier 46
Observation data (J2000.0 epoch)
Right ascension	07h 41.8m
Declination	−14° 49′
Distance	5.4 kly (1.7 kPc)
Apparent magnitude (V)	6.1
Apparent dimensions (V)	27.0′
Physical characteristics
Radius	15
Estimated age	300 million years
Notable features	contains superimposed planetary nebula NGC 2438
Other designations	NGC 2437
See also: Open cluster, List of open clusters

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 with an estimated age on the order of several 100 million years.^[1]

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.^[1][2] The case is yet another example of a superposed pair, joining the famed case of NGC 2818.^[1][3]

M46 is about a degree east of M47 in the sky, so the two fit well in a binocular or wide-angle telescope field.

References

1. ^ ^{a b c} Majaess D. J., Turner D., Lane D. (2007). "In Search of Possible Associations between Planetary Nebulae and Open Clusters". Publications of the Astronomical Society of the Pacific 119: 1349. arXiv:0710.2900. Bibcode 2007PASP..119.1349M. doi:10.1086/524414. 
2. ^ Kiss, L. L., Szabó, Gy. M., Balog, Z., Parker, Q. A., Frew, D. J. (2008). "AAOmega radial velocities rule out current membership of the planetary nebula NGC 2438 in the open cluster M46". Monthly Notices of the Royal Astronomical Society. arXiv:0809.0327. Bibcode 2008MNRAS.391..399K. doi:10.1111/j.1365-2966.2008.13899.x. 
3. ^ Mermilliod, J.-C., Clariá, J. J., Andersen, J., Piatti, A. E., Mayor, M. (2001). "Red giants in open clusters. IX. NGC 2324, 2818, 3960 and 6259". Astrophysics and Astronomy 375: 30. Bibcode 2001A&A...375...30M. doi:10.1051/0004-6361:20010845. 

External links

• Messier 46, SEDS Messier pages
• Messier 46, Amateur Astronomer Image - Waid Obseratory
• 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

See also

Coordinates: 07^h 41.8^m 00^s, −14° 49′ 00″