Astronomy:Iota Geminorum
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Gemini |
| Right ascension | 07h 25m 43.59532s[1] |
| Declination | +27° 47′ 53.0929″[1] |
| Apparent magnitude (V) | 3.791[2] |
| Characteristics | |
| Spectral type | G9 III[3] |
| U−B color index | +0.88[2] |
| B−V color index | +1.01[2] |
| Astrometry | |
| Radial velocity (Rv) | 7.26±0.16[4] km/s |
| Proper motion (μ) | RA: −122.66[1] mas/yr Dec.: −84.03[1] mas/yr |
| Parallax (π) | 27.10 ± 0.20[1] mas |
| Distance | 120.4 ± 0.9 ly (36.9 ± 0.3 pc) |
| Absolute magnitude (MV) | +0.859[5] |
| Details[4] | |
| Mass | 1.89[6] M☉ |
| Radius | 10 R☉ |
| Luminosity | 48 L☉ |
| Surface gravity (log g) | 2.8 cgs |
| Temperature | 4,753 K |
| Metallicity [Fe/H] | −0.17 dex |
| Rotational velocity (v sin i) | 0.0 km/s |
| Age | 4.16±2.54[5] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Iota Geminorum (ι Geminorum, ι Gem) is a solitary[8] fourth-magnitude star in the constellation Gemini. In the sky, it forms an isosceles triangle with Castor and Pollux, and is located less than a degree from the 5th magnitude stars 64 and 65 Geminorum.[9]
Nomenclature
In Chinese, 五諸侯 (Wu Zhū Hóu), meaning Five Feudal Kings, refers to an asterism consisting of ι Geminorum, θ Geminorum, τ Geminorum, υ Geminorum and φ Geminorum.[10] Consequently, ι Geminorum itself is known as 五諸侯三 (Wu Zhū Hóu sān, English: the Third Star of Five Feudal Kings.).[11] It has been called by the proper name Propus, meaning "forefoot" in Latin, but this name is now assigned to η Geminorum.[12]
Properties
Based upon an annual parallax shift of 27.10 mass,[1] Iota Geminorum lies some 120.4 light years from the Sun. This is an evolved red clump[13] giant star with a stellar classification of G9 III.[3] It is most likely a member of the galactic thin disk population.[5] The star has 1.89[6] times the mass of the Sun, but has expanded to 10 times the solar radius. It shines with 48[4] times the Sun's luminosity from its outer atmosphere at an effective temperature of 4,753 K.[4]
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 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 Morgan, W. W.; Keenan, P. C. (1973), "Spectral Classification", Annual Review of Astronomy and Astrophysics 11: 29, doi:10.1146/annurev.aa.11.090173.000333, Bibcode: 1973ARA&A..11...29M.
- ↑ 4.0 4.1 4.2 4.3 Massarotti, Alessandro et al. (January 2008), "Rotational and radial velocities for a sample of 761 HIPPARCOS giants and the role of binarity", The Astronomical Journal 135 (1): 209–231, doi:10.1088/0004-6256/135/1/209, Bibcode: 2008AJ....135..209M.
- ↑ 5.0 5.1 5.2 Soubiran, C. et al. (March 2008), "Vertical distribution of Galactic disk stars. IV. AMR and AVR from clump giants", Astronomy and Astrophysics 480 (1): 91–101, doi:10.1051/0004-6361:20078788, Bibcode: 2008A&A...480...91S.
- ↑ 6.0 6.1 Luck, R. Earle (September 2015), "Abundances in the Local Region. I. G and K Giants", The Astronomical Journal 150 (3): 23, doi:10.1088/0004-6256/150/3/88, 88, Bibcode: 2015AJ....150...88L.
- ↑ "iot Gem". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=iot+Gem.
- ↑ Eggleton, P. P.; Tokovinin, A. A. (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.
- ↑ O'Meara, Steve (2007), Herschel 400 Observing Guide, Cambridge University Press, p. 76, ISBN 978-0521858939, https://books.google.com/books?id=Nyh9fAC_tpIC&pg=PA76.
- ↑ 陳久金 (2005) (in zh). 中國星座神話. 五南圖書出版股份有限公司. ISBN 978-986-7332-25-7. https://books.google.com/books?id=0Vex0rYzdu8C.
- ↑ "研究資源 - 亮星中英對照表" (in zh). 香港太空館. http://www.lcsd.gov.hk/CE/Museum/Space/Research/StarName/c_research_chinengstars_n_r.htm.
- ↑ "Naming stars". IAU. https://www.iau.org/public/themes/naming_stars/.
- ↑ Puzeras, E. et al. (October 2010), "High-resolution spectroscopic study of red clump stars in the Galaxy: iron-group elements", Monthly Notices of the Royal Astronomical Society 408 (2): 1225–1232, doi:10.1111/j.1365-2966.2010.17195.x, Bibcode: 2010MNRAS.408.1225P.
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