3 Piscis Austrini
3 Piscis Austrini, also known as HD 201901, is a suspected astrometric binary[7] star system that, despite its Flamsteed designation, is actually located in the constellation Microscopium. It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 5.41.[6] The system is moving closer to the Earth with a heliocentric radial velocity of −46 km/s.[2] It is following a highly elliptical orbit around the Galactic Center, moving between a pericenter of 2.6 kpc out to an apocenter of 7.6 kpc, with an orbital eccentricity of 0.49.[2]
Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Microscopium |
Right ascension | 12h 11m 17.33721s[1] |
Declination | −23° 36′ 09.6123″[1] |
Apparent magnitude (V) | 5.41[2] |
Characteristics | |
Evolutionary stage | giant |
Spectral type | K3 III[3] |
B−V color index | 1.425±0.006[2] |
Astrometry | |
Radial velocity (Rv) | −46.2±2.4[2] km/s |
Proper motion (μ) | RA: +90.349[1] mas/yr Dec.: −117.051[1] mas/yr |
Parallax (π) | 10.6862 ± 0.3860[1] mas |
Distance | 310 ± 10 ly (94 ± 3 pc) |
Absolute magnitude (MV) | 0.19[2] |
Details | |
Radius | 20[4] R☉ |
Luminosity | 173.80[2] L☉ |
Surface gravity (log g) | 1.86[5] cgs |
Temperature | 4,050[5] K |
Metallicity [Fe/H] | −0.17[5] dex |
Other designations | |
Database references | |
SIMBAD | data |
The visible component is an evolved giant star with a stellar classification of K3 III.[3] The interferometry-measured angular diameter of the star, after correcting for limb darkening, is 2.03±0.04 mas,[8] which, at its estimated distance, equates to a physical radius of about 20 times the radius of the Sun.[4] It is radiating 174[2] times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 4,050 K.[5]
References
- Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015.
- Houk, Nancy (1979), Michigan catalogue of two-dimensional spectral types for the HD stars, 3, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, Bibcode:1982mcts.book.....H.
- Lang, Kenneth R. (2006), Astrophysical formulae, Astronomy and astrophysics library, 1 (3rd ed.), Birkhäuser, ISBN 3-540-29692-1. The radius (R*) is given by:
- McWilliam, Andrew (December 1990), "High-resolution spectroscopic survey of 671 GK giants. I - Stellar atmosphere parameters and abundances", Astrophysical Journal Supplement Series, 74: 1075–1128, Bibcode:1990ApJS...74.1075M, doi:10.1086/191527
- "HD 201901". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-04-11.
- 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, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x.
- Richichi, A.; et al. (February 2005), "CHARM2: An updated Catalog of High Angular Resolution Measurements", Astronomy and Astrophysics, 431: 773–777, Bibcode:2005A&A...431..773R, doi:10.1051/0004-6361:20042039.