Messier 47 (M47 or NGC 2422), also known as NGC 2478[3] is an open cluster in the southern constellation of Puppis. It was discovered by Giovanni Batista Hodierna before 1654 and re-discovered by Charles Messier in 1771. It was also independently discovered by Caroline Herschel.
| Messier 47 | |
|---|---|
 Open cluster Messier 47 | |
| Observation data (J2000.0 epoch) | |
| Right ascension | 07h 36.6m [1] |
| Declination | −14° 30′[1] |
| Distance | 498 pc[1] |
| Apparent magnitude (V) | 4.4[2] |
| Apparent dimensions (V) | 30′[2] |
| Physical characteristics | |
| Mass | 453[1] M☉ |
| Radius | 10.61 pc[1] |
| Estimated age | 78 million years |
| Other designations | NGC 2422, NGC 2478, Cr 152 |
| Associations | |
There is no cluster in the position indicated by Messier, which he expressed in terms of its right ascension and declination with respect to the star 2 Puppis. However, if the signs (+ and −) that he wrote are swapped, the position matches.[4] Until that equivalency was found, M47 was considered a lost Messier Object. The identification was made in 1959 by Canadian astronomer T. F. Morris.[5]
M47 is about 1,600 light-years away and is about 78 million years old. The member stars have been measured down to red dwarfs at apparent magnitude 19. There are around 500 members,[1] the brightest being HD 60855, a magnitude 5.7 Be star. The cluster is dominated by hot class B main sequence and giant stars, but a noticeable colour contrast comes from its brightest red giants.[5]
It about a degree from Messier 46, which is much older and much further away.[5]
See also
editReferences and footnotes
edit- 1 2 3 4 5 6 Prisinzano, L; Micela, G; Sciortino, S; Favata, F (2003). "Luminosity and Mass Function of the Galactic open cluster NGC 2422". Astronomy & Astrophysics. 404 (3): 927–938. arXiv:astro-ph/0304321. Bibcode:2003A&A...404..927P. doi:10.1051/0004-6361:20030524. S2CID 14697851.
- 1 2 Stoyan, Ronald (2008). Atlas of the Messier Objects: Highlights of the Deep Sky. Cambridge University Press. p. 195. ISBN 978-0521895545.
- ↑ "NGC/IC Project Restoration Efforts". ngcicproject.observers.org. Retrieved 2024-08-02.
- ↑ Houston, Walter Scott (2005). Deep-Sky Wonders. Sky Publishing Corporation. ISBN 978-1-931559-23-2.
- 1 2 3 "The hot blue stars of messier 47". ScienceDaily. 17 December 2014.
External links
edit
Media related to Messier 47 at Wikimedia Commons- Messier 47, SEDS Messier pages
- Messier 47 Amateur Image - Waid Observatory
- Messier 47 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images
