Astronomy:Rho1 Cephei
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Cepheus |
| Right ascension | 22h 26m 42.40624s[1] |
| Declination | +78° 47′ 09.0725″[1] |
| Apparent magnitude (V) | 5.84[2] |
| Characteristics | |
| Spectral type | A2m[3] |
| B−V color index | −0.16[2] |
| Astrometry | |
| Proper motion (μ) | RA: −13.33[1] mas/yr Dec.: −36.95[1] mas/yr |
| Parallax (π) | 15.83 ± 0.23[1] mas |
| Distance | 206 ± 3 ly (63.2 ± 0.9 pc) |
| Details | |
| ρ1 Cep A | |
| Mass | 2.00[3] M☉ |
| Rotational velocity (v sin i) | 81[4] km/s |
| Age | 320[3] Myr |
| ρ1 Cep B | |
| Mass | 0.51[3] M☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
Rho1 Cephei (ρ1 Cephei) is a double star located in the northern constellation of Cepheus. As of 2014, the pair had an angular separation of 0.29 arc seconds along a position angle of 211.1°. This corresponds to a projected separation of 18.1 AU.[3] Rho1 Cephei is faintly visible to the naked eye with an apparent visual magnitude of 5.84,[2] and it forms an optical pair with the brighter star Rho2 Cephei. Based upon an annual parallax shift of 15.83 mas as seen from the Earth,[1] Rho1 Cephei is located about 206 light years from the Sun.
The primary component is a chemically peculiar Am star with a stellar classification of A2m.[3] It has twice the mass of the Sun and is around 320 million years old.[3] The smaller companion may be the source of the X-ray emission from this location, as stars similar to the primary component do not generally produce detectable levels of X-rays.[6]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode: 2007A&A...474..653V.
- ↑ 2.0 2.1 2.2 Oja, T. (August 1991), "UBV photometry of stars whose positions are accurately known. VI", Astronomy and Astrophysics Supplement Series 89 (2): 415–419, Bibcode: 1991A&AS...89..415O.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 De Rosa, R. J. et al. (2013), "The VAST Survey - III. The multiplicity of A-type stars within 75 pc", Monthly Notices of the Royal Astronomical Society 437 (2): 1216, doi:10.1093/mnras/stt1932, Bibcode: 2014MNRAS.437.1216D.
- ↑ Royer, F. et al. (October 2002), "Rotational velocities of A-type stars in the northern hemisphere. II. Measurement of v sin i", Astronomy and Astrophysics 393: 897–911, doi:10.1051/0004-6361:20020943, Bibcode: 2002A&A...393..897R.
- ↑ "rho01 Cep". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=rho01+Cep.
- ↑ De Rosa, R. J. et al. (July 2011), "The Volume-limited A-Star (VAST) survey - I. Companions and the unexpected X-ray detection of B6-A7 stars", Monthly Notices of the Royal Astronomical Society 415 (1): 854–866, doi:10.1111/j.1365-2966.2011.18765.x, Bibcode: 2011MNRAS.415..854D.
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