Astronomy:Iota Cephei
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| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Cepheus |
| Right ascension | 22h 49m 40.817s[1] |
| Declination | +66° 12′ 01.46″[1] |
| Apparent magnitude (V) | 3.507[2] |
| Characteristics | |
| Evolutionary stage | red clump[3] |
| Spectral type | K0 III[4] |
| U−B color index | +0.924[2] |
| B−V color index | +1.053[2] |
| Astrometry | |
| Radial velocity (Rv) | −12.763±0.0008[5] km/s |
| Proper motion (μ) | RA: −65.89[1] mas/yr Dec.: −125.17[1] mas/yr |
| Parallax (π) | 28.29 ± 0.10[1] mas |
| Distance | 115.3 ± 0.4 ly (35.3 ± 0.1 pc) |
| Absolute magnitude (MV) | 0.76[4] |
| Details[6] | |
| Mass | 2.15±0.23 M☉ |
| Radius | 11.02±0.09[7] R☉ |
| Luminosity | 57.0±0.6 L☉ |
| Surface gravity (log g) | 2.69±0.06 cgs |
| Temperature | 4,768±33 K |
| Metallicity [Fe/H] | +0.05±0.10 dex |
| Rotational velocity (v sin i) | 10[8] km/s |
| Age | 1.2±0.6 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Iota Cephei is a star in the northern constellation Cepheus. Its name is a Bayer designation that is Latinized from ι Cephei, and abbreviated Iota Cep or ι Cep. Based upon an annual parallax shift of 28.29 mas as seen from the Earth,[1] it is located about 115 light-years (35 pc) from the Sun. The star is visible to the naked eye with an apparent visual magnitude of 3.5.[2]
It is a K-type giant star with a stellar classification of K0 III.[4] It is currently at an evolutionary stage known as the red clump, indicating that it is generating energy through the fusion of helium at its core.[3] It has 11 times the Sun's radius[7] and about 2.15 times the mass of the Sun. Its luminosity is 57 times that of the Sun, and its surface has an effective temperature of 4,768 K.[6]
Pole star
| Preceded by | Pole Star | Succeeded by |
|---|---|---|
| Errai | 5200AD to 7500AD with Alfirk |
Alderamin |
References
- ↑ 1.0 1.1 1.2 1.3 1.4 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 2.3 Jennens, P. A.; Helfer, H. L. (September 1975), "A new photometric metal abundance and luminosity calibration for field G and K giants", Monthly Notices of the Royal Astronomical Society 172 (3): 667–679, doi:10.1093/mnras/172.3.667, Bibcode: 1975MNRAS.172..667J.
- ↑ 3.0 3.1 Tautvaišienė, G. et al. (December 2010), "C, N and O abundances in red clump stars of the Milky Way", Monthly Notices of the Royal Astronomical Society 409 (3): 1213–1219, doi:10.1111/j.1365-2966.2010.17381.x, Bibcode: 2010MNRAS.409.1213T.
- ↑ 4.0 4.1 4.2 Hekker, S. et al. (August 2006), "Precise radial velocities of giant stars. I. Stable stars", Astronomy and Astrophysics 454 (3): 943–949, doi:10.1051/0004-6361:20064946, Bibcode: 2006A&A...454..943H.
- ↑ 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.
- ↑ 6.0 6.1 Reffert, Sabine et al. (2015), "Precise radial velocities of giant stars. VII. Occurrence rate of giant extrasolar planets as a function of mass and metallicity", Astronomy & Astrophysics 574: A116, doi:10.1051/0004-6361/201322360, Bibcode: 2015A&A...574A.116R.
- ↑ 7.0 7.1 Anugu, Narsireddy; Monnier, John D.; Mérand, Antoine; Flores, Becky; Gallenne, Alexandre; Gies, Douglas R.; Gutierrez, Mayra; Klement, Robert et al. (2026-07-27), "Empirical H- and K-band Limb Darkening for 31 CHARA Stars: A Near-Infrared Benchmark for Stellar-Atmosphere Models", The Astronomical Journal.
- ↑ Bernacca, P. L.; Perinotto, M. (1970), "A catalogue of stellar rotational velocities", Contributi Osservatorio Astronomico di Padova in Asiago 239 (1): 1, Bibcode: 1970CoAsi.239....1B.
- ↑ "iot Cep". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=iot+Cep.
Coordinates: 
22h 49m 40.91s, +66° 12′ 2.6″
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