Astronomy:2 Sextantis
  | |
| Observation data Epoch J2000.0 Equinox (celestial coordinates) | |
|---|---|
| Constellation | Hydra[1] |
| Right ascension | 09h 38m 27.28962s[2] |
| Declination | +04° 38′ 57.4461″[2] |
| Apparent magnitude (V) | 4.68[3] |
| Characteristics | |
| Evolutionary stage | giant |
| Spectral type | K3 III[3] |
| B−V color index | +1.310±0.033[1] |
| Astrometry | |
| Radial velocity (Rv) | +44.61±0.23[4] km/s |
| Proper motion (μ) | RA: −163.18[2] mas/yr Dec.: −50.88[2] mas/yr |
| Parallax (π) | 11.04 ± 0.27[2] mas |
| Distance | 295 ± 7 ly (91 ± 2 pc) |
| Absolute magnitude (MV) | −0.10[1] |
| Details | |
| Mass | 1.32[3] M☉ |
| Radius | 24[4] R☉ |
| Luminosity | 191[3] L☉ |
| Surface gravity (log g) | 2.09±0.22[5] cgs |
| Temperature | 4,188±33[3] K |
| Metallicity [Fe/H] | −0.30±0.09[5] dex |
| Rotational velocity (v sin i) | 3.0[4] km/s |
| Age | 4.58[3] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
2 Sextantis is a single[7] star that is now in the equatorial constellation Hydra with the Bayer designation H Hydrae.[8] It is located around 295 light-years away from the Sun and it is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.68.[3] This object is moving further from the Earth with a heliocentric radial velocity of +44.6 km/s.[4] It has a relatively high proper motion, traversing the celestial sphere at the rate of 0.173″ per year.[9]
This is a giant star with a stellar classification of K3 III,[3] which, at the age of 4.58[3] billion years old, has exhausted the hydrogen at its core and evolved away from the main sequence. The star has 1.32 times the mass of the Sun[3] and has expanded to 24 times the Sun's radius.[4] It is radiating 191 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 4,188 K.[3]
References
- ↑ 1.0 1.1 1.2 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A XHIP record for this object at VizieR.
- ↑ 2.0 2.1 2.2 2.3 2.4 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.
- ↑ 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 Luck, R. Earle (2015), "Abundances in the Local Region. I. G and K Giants", The Astronomical Journal 150 (3): 88, doi:10.1088/0004-6256/150/3/88, Bibcode: 2015AJ....150...88L.
- ↑ 4.0 4.1 4.2 4.3 4.4 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 Prugniel, Ph. et al. (July 2011), "The atmospheric parameters and spectral interpolator for the MILES stars", Astronomy & Astrophysics 531: A165, doi:10.1051/0004-6361/201116769, Bibcode: 2011A&A...531A.165P.
- ↑ "2 Sex". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=2+Sex.
- ↑ 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.
- ↑ Morton Wagman (2003). Lost Stars: Lost, Missing, and Troublesome Stars from the Catalogues of Johannes Bayer, Nicholas-Louis de Lacaille, John Flamsteed, and Sundry Others (2 ed.). McDonald & Woodward Publishing Company. ISBN 978-0-939923-78-6. OCLC 1131243914. https://books.google.com/books?id=TYLvAAAAMAAJ.
- ↑ 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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