Astronomy:NGC 7790
| NGC 7790 | |
|---|---|
 NGC 7790 (taken from Stellarium) Credit: Roberto Mura | |
| Observation data (J2000.0 epoch) | |
| Constellation | Cassiopeia |
| Right ascension | 23h 58m 24.2s[1] |
| Declination | +61° 12′ 30″[1] |
| Distance | 10.76 ± 0.75 kly (3.30 ± 0.23 kpc)[2] |
| Apparent magnitude (V) | 8.5 |
| Apparent dimensions (V) | 7′.4[2] diameter |
| Physical characteristics | |
| Estimated age | 60–80[3] Myr |
| Other designations | Cr 461 |
NGC 7790 is a young open cluster[1] of stars located some 10,800[2] light years away from Earth in the northern constellation of Cassiopeia. At this distance, the light from the cluster has undergone extinction from interstellar gas and dust equal to E(B – V ) = 0.51 magnitude in the UBV photometric system. NGC 7790 has a Trumpler class rating of II2m[2] and the estimated age is 60–80 million years.[3] It contains three cepheid variables: CEa Cas, CEb Cas, and CF Cas.[2]
This cluster is on an orbit through the Milky Way galaxy that has an eccentricity of 0.22 ± 0.07 and a period of (225.0 ± 27.1) million years. It will come as close as 20.2 ± 3.9 kly (6.2 ± 1.2 kpc) to, and as distant as 31.6 ± 2.9 kly (9.7 ± 0.9 kpc) from, the Galactic Center. The maximum distance reached above (or below) the galactic plane is 0.78 ± 1.30 kly (0.24 ± 0.40 kpc). On average, it will cross the galactic plane every (35.7 ± 13.0) million years.[4]
References
- ↑ 1.0 1.1 1.2 Revised New General Catalogue and Index Catalogue, Wolfgang Steinicke, February 2009, http://www.klima-luft.de/steinicke/ngcic/rev2000/NI2009.zip, retrieved 2013-07-01.
- ↑ 2.0 2.1 2.2 2.3 2.4 Gupta, A. C. et al. (September 2000), "A complete photometric study of the open cluster NGC 7790 containing Cepheid variables", Astronomy and Astrophysics Supplement 145 (3): 365–375, doi:10.1051/aas:2000247, Bibcode: 2000A&AS..145..365G.
- ↑ 3.0 3.1 Davidge, T. J. (December 2012), "The Young Open Clusters King 12, NGC 7788, and NGC 7790: Pre-main-sequence Stars and Extended Stellar Halos", The Astrophysical Journal 761 (2): 155, doi:10.1088/0004-637X/761/2/155, Bibcode: 2012ApJ...761..155D.
- ↑ Wu, Zhen-Yu et al. (November 2009), "The orbits of open clusters in the Galaxy", Monthly Notices of the Royal Astronomical Society 399 (4): 2146–2164, doi:10.1111/j.1365-2966.2009.15416.x, Bibcode: 2009MNRAS.399.2146W.
External links
- NGC 7790 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images
Coordinates: 
23h 58m 24.2s, +61° 12′ 30″
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