Astronomy:11 Cephei
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Cepheus |
| Right ascension | 21h 41m 55.31069s[1] |
| Declination | +71° 18′ 41.2585″[1] |
| Apparent magnitude (V) | 4.55[2] |
| Characteristics | |
| Evolutionary stage | horizontal branch[3] |
| Spectral type | K0.5 III[4] |
| B−V color index | 1.108±0.004[2] |
| Astrometry | |
| Radial velocity (Rv) | −38.36±0.19[2] km/s |
| Proper motion (μ) | RA: +111.130[1] mas/yr Dec.: +92.743[1] mas/yr |
| Parallax (π) | 17.6830 ± 0.1814 mas |
| Distance | 184 ± 2 ly (56.6 ± 0.6 pc) |
| Absolute magnitude (MV) | 0.16[2] |
| Details[5] | |
| Mass | 2.38±0.07 M☉ |
| Radius | 10.93+0.27 −0.26 R☉ |
| Luminosity | 94.9±8.8 L☉ |
| Surface gravity (log g) | 2.41 cgs |
| Temperature | 5,446±113 K |
| Metallicity [Fe/H] | 0.17 dex |
| Rotational velocity (v sin i) | 1.0[6] km/s |
| Age | 670±60 Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
11 Cephei is a single[8] star in the northern constellation of Cepheus,[7] located 184 light years away from the Sun.[1] It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.55.[2] The star has a relatively high proper motion, traversing the celestial sphere at the rate of 0.153 arc seconds per annum.[9] It is moving closer to the Earth with a heliocentric radial velocity of −38 km/s.[2]
This is an aging giant star with a stellar classification of K0.5 III,[4] having exhausted the hydrogen at its core and expanded. It is a red clump giant, which means it is currently on the horizontal branch and is generating energy through helium fusion at the core.[3] 11 Cephei is 670 million years old with 2.4 times the mass of the Sun and 11 times the Sun's radius. It is radiating around 95 times the luminosity of the Sun from its swollen photosphere at an effective temperature of 5,446 K.[5]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 3.0 3.1 Alves, David R. (August 2000), "K-Band Calibration of the Red Clump Luminosity", The Astrophysical Journal 539 (2): 732–741, doi:10.1086/309278, Bibcode: 2000ApJ...539..732A.
- ↑ 4.0 4.1 Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series 71: 245, doi:10.1086/191373, ISSN 0067-0049, Bibcode: 1989ApJS...71..245K.
- ↑ 5.0 5.1 Baines, Ellyn K. et al. (2018), "Fundamental Parameters of 87 Stars from the Navy Precision Optical Interferometer", The Astronomical Journal 155 (1): 30, doi:10.3847/1538-3881/aa9d8b, Bibcode: 2018AJ....155...30B.
- ↑ De Medeiros, J. R. et al. (November 2000), "Rotation and lithium in single giant stars", Astronomy and Astrophysics 363: 239–243, Bibcode: 2000A&A...363..239D.
- ↑ 7.0 7.1 "11 Cep". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=11+Cep.
- ↑ Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society 389 (2): 869–879, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E.
- ↑ Lépine, Sébastien; Shara, Michael M. (March 2005), "A Catalog of Northern Stars with Annual Proper Motions Larger than 0.15" (LSPM-NORTH Catalog)", The Astronomical Journal 129 (3): 1483–1522, doi:10.1086/427854, Bibcode: 2005AJ....129.1483L.
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