Psi1 Lupi
Psi1 Lupi, which is Latinized from ψ1 Lupi, is a single[8] star in the southern constellation of Lupus. It has a yellow-white hue and is faintly visible to the naked eye with an apparent visual magnitude of +4.66.[2] The star is located at a distance of approximately 207 light years from the Sun based on parallax.[1] It is drifting closer with a radial velocity of −23 km/s, and is predicted to come to within 36 light-years in 2.8 million years.[4]
| Observation data Epoch 2000 Equinox 2000 | |
|---|---|
| Constellation | Lupus |
| Right ascension | 15h 39m 45.97931s[1] |
| Declination | –34° 24′ 42.9073″[1] |
| Apparent magnitude (V) | +4.663[2] |
| Characteristics | |
| Spectral type | G8/K0 III[3] |
| B−V color index | 0.964±0.047[4] |
| Astrometry | |
| Radial velocity (Rv) | −23.1±0.8[4] km/s |
| Proper motion (μ) | RA: +6.123[1] mas/yr Dec.: −11.767[1] mas/yr |
| Parallax (π) | 15.7610 ± 0.2700[1] mas |
| Distance | 207 ± 4 ly (63 ± 1 pc) |
| Absolute magnitude (MV) | +0.24[5] |
| Details | |
| Mass | 2.42[5] M☉ |
| Radius | 10.76+0.20 −0.08[1] R☉ |
| Luminosity | 62.0±1.2[1] L☉ |
| Surface gravity (log g) | 3.28[6] cgs |
| Temperature | 4,939+17 −46[1] K |
| Metallicity [Fe/H] | −0.34[6] dex |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is an evolved giant star with a stellar classification of G8/K0 III.[3] With the hydrogen exhausted at its core, the star has cooled and expanded to 11 times the radius of the Sun.[1] It is a red clump[2] giant, which indicates it is on the horizontal branch and is generating energy through core helium fusion. The star has an estimated 2.4[5] times the Sun's mass and is radiating 62 times the luminosity of the Sun from its photosphere at an effective temperature of 4,939 K.[1]
The star is surrounded by a cold circumstellar envelope, hinted at by the anomaly of the small observed power of the doublet Mg II emission at 2800 angstrom. The absorption cores on the peaks of the emission profiles Mg II k and h are mainly of interstellar origin and only partly due to self-absorption in the star's chromosphere.[9]
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.
- Alves, David R. (2000). "K-Band Calibration of the Red Clump Luminosity". The Astrophysical Journal. 539 (2): 732–741. arXiv:astro-ph/0003329. Bibcode:2000ApJ...539..732A. doi:10.1086/309278.
- Houk, N. (1982). "Michigan Catalogue of Two-dimensional Spectral Types for the HD stars". 3. Bibcode:1982mcts.book.....H. Cite journal requires
|journal=(help) - 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.
- Pizzolato, N.; Maggio, A.; Sciortino, S. (September 2000), "Evolution of X-ray activity of 1-3 Msun late-type stars in early post-main-sequence phases", Astronomy and Astrophysics, 361: 614–628, Bibcode:2000A&A...361..614P
- Adibekyan, V. Zh.; et al. (2015). "Chemical abundances and kinematics of 257 G-, K-type field giants. Setting a base for further analysis of giant-planet properties orbiting evolved stars". Monthly Notices of the Royal Astronomical Society. 450 (2): 1900. arXiv:1503.08346. Bibcode:2015MNRAS.450.1900A. doi:10.1093/mnras/stv716.
- "psi01 Lup". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-08-16.
- 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. arXiv:0806.2878. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x.
- Gurzadian, G. A.; et al. (1991). "A cool giant with a circumstellar cloud". Astrophysics and Space Science. 176 (1): 61–68. Bibcode:1991Ap&SS.176...61G. doi:10.1007/BF00643077.