Astronomy:2 Lupi
| Observation data Epoch J2000.0 Equinox (celestial coordinates) | |
|---|---|
| Constellation | Lupus |
| Right ascension | 15h 17m 49.83809s[1] |
| Declination | −30° 08′ 55.2165″[1] |
| Apparent magnitude (V) | 4.33[2] |
| Characteristics | |
| Evolutionary stage | giant |
| Spectral type | K0 IIIa CH-1[3] |
| B−V color index | 1.100±0.004[4] |
| Astrometry | |
| Radial velocity (Rv) | −2.91±0.15[5] km/s |
| Proper motion (μ) | RA: −10.16[1] mas/yr Dec.: −3.66[1] mas/yr |
| Parallax (π) | 10.01 ± 0.21[1] mas |
| Distance | 326 ± 7 ly (100 ± 2 pc) |
| Absolute magnitude (MV) | −0.65[4] |
| Details | |
| Radius | 11.0+0.7 −0.8[5] R☉ |
| Luminosity | 65.6±0.8[5] L☉ |
| Surface gravity (log g) | 2.84[2] cgs |
| Temperature | 4,953+197 −148[5] K |
| Metallicity [Fe/H] | 0.11[2] dex |
| Other designations | |
| Database references | |
| SIMBAD | data |
2 Lupi is a single[7] star in the southern constellation of Lupus,[6] located 326 light-years away from the Sun.[1] It has the Bayer designation f Lupi; 2 Lupi is the Flamsteed designation. This object is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.33.[2] It is moving closer to the Earth with a heliocentric radial velocity of −3 km/s.[5]
This is an aging giant star with a stellar classification of K0 IIIa CH-1.[3] The suffix notation indicates abnormally weak lines of carbyne. Having exhausted the hydrogen at its core, the star evolved away from the main sequence by expanding to 11[5] times the Sun's radius. The star is radiating 65.6[5] times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 4,953 K.[5] It is a suspected variable star of unknown type.[8]
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 2.3 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, doi:10.1086/191527, Bibcode: 1990ApJS...74.1075M
- ↑ 3.0 3.1 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, Bibcode: 1989ApJS...71..245K
- ↑ 4.0 4.1 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 5.0 5.1 5.2 5.3 5.4 5.5 5.6 5.7 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 "2 Boo". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=2+Boo.
- ↑ 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.
- ↑ Samus, N. N. et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, 5.1 61 (1): 80–88, doi:10.1134/S1063772917010085, Bibcode: 2017ARep...61...80S.
 |  |
