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]

For other stars with this Bayer designation, see ψ Lupi.
ψ1 Lupi
Observation data
Epoch J2000      Equinox J2000
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
Distance207 ± 4 ly
(63 ± 1 pc)
Absolute magnitude (MV)+0.24[5]
Details
Mass2.42[5] M☉
Radius10.76+0.20
−0.08[1] R☉
Luminosity62.0±1.2[1] L☉
Surface gravity (log g)3.28[6] cgs
Temperature4,939+17
−46[1] K
Metallicity [Fe/H]−0.34[6] dex
Other designations
ψ1 Lup, 3 Lup, CD−33°10631, FK5 3237, HD 139521, HIP 76705, HR 5820, SAO 206843[7]
Database references
SIMBADdata

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
  1. 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.
  2. 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. S2CID 16673121.
  3. Houk, N. (1982). Michigan Catalogue of Two-dimensional Spectral Types for the HD stars. 3. Bibcode:1982mcts.book.....H.
  4. 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. S2CID 119257644.
  5. 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
  6. 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. S2CID 58920318.
  7. "psi01 Lup". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-08-16.
  8. 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. S2CID 14878976.
  9. 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. S2CID 122673985.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.