HD 140913

HD 140913 is a star very much like our own Sun located in the northern constellation of Corona Borealis (The Northern Crown). It is too faint to be visible to the naked eye with an apparent visual magnitude of 8.07.[2] The star is located at a distance of 158 light years from the Sun based on parallax. Prior to the discovery of a companion, this served as an IAU radial velocity standard,[8] and it is receding from the Sun at a rate of +37 km/s.[5] The space velocity components of this star are (U, V, W) = (-21.77, -14.42, 1.67).[3]

HD 140913
Observation data
Epoch J2000      Equinox J2000
Constellation Corona Borealis
Right ascension 15h 45m 07.44930s[1]
Declination +28° 28′ 11.7430″[1]
Apparent magnitude (V) 8.07[2]
Characteristics
Spectral type G0V[3]
B−V color index 0.612±0.007[4]
Astrometry
Radial velocity (Rv)+37[5] km/s
Proper motion (μ) RA: −88.050[1] mas/yr
Dec.: 37.704[1] mas/yr
Parallax (π)20.6710 ± 0.0456[1] mas
Distance157.8 ± 0.3 ly
(48.4 ± 0.1 pc)
Absolute magnitude (MV)4.81[2]
Orbit[6]
Period (P)147.968±0.001 d
Semi-major axis (a)≥0.55 AU
Eccentricity (e)0.54 (fixed)
Periastron epoch (T)2,451,321.42±0.02 JD
Argument of periastron (ω)
(secondary)		18±1°
Semi-amplitude (K1)
(primary)		1.94±0.01 km/s
Details[2]
Mass0.92 M☉
Radius1.02±0.03[1] R☉
Luminosity1.188±0.004[1] L☉
Surface gravity (log g)4.46 cgs
Temperature5,957±87[1] K
Metallicity [Fe/H]0.05 dex
Rotational velocity (v sin i)9.7 km/s
Age7.13 Gyr
Other designations
BD+28°2469, HD 140913, HIP 77152, SAO 83985[7]
Database references
SIMBADdata

This is a solar-type star[9] with a stellar classification of G0V.[3] It is an estimated seven billion years old and is spinning with a projected rotational velocity of 9.7 km/s.[2] The star is about the same size[1] as the Sun with 92% of the Sun's mass.[2] It is radiating 1.2 times the Sun's luminosity from its photosphere at an effective temperature of 5,957 K.[1]

The detection of an orbiting companion, designated HD 140913 B, was announced in 1994.[8][9] The minimum mass of this object is 43.2 times the mass of Jupiter, making it a brown dwarf candidate. Alternatively, it may be an under-mass helium white dwarf that has lost its envelope during a mass transfer.[10] It orbits the host star about every 148 days with an eccentricity (ovalness) of ~0.57 and a semimajor axis of at least 0.55 AU.[6]

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. Luck, R. Earle (January 2017). "Abundances in the Local Region II: F, G, and K Dwarfs and Subgiants". The Astronomical Journal. 153 (1): 19. arXiv:1611.02897. Bibcode:2017AJ....153...21L. doi:10.3847/1538-3881/153/1/21. 21.
  3. Montes, D.; et al. (November 2001). "Late-type members of young stellar kinematic groups - I. Single stars" (PDF). Monthly Notices of the Royal Astronomical Society. 328 (1): 45–63. arXiv:astro-ph/0106537. Bibcode:2001MNRAS.328...45M. doi:10.1046/j.1365-8711.2001.04781.x.
  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. Evans, D. S. (1967). "The revision of the general catalogue of radial velocities". In Batten, Alan Henry; Heard, John Frederick (eds.). Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30. University of Toronto: Academic Press. Bibcode:1967IAUS...30...57E.
  6. Nidever, David L.; et al. (August 2002). "Radial Velocities for 889 Late-Type Stars". The Astrophysical Journal Supplement Series. 141 (2): 503–522. arXiv:astro-ph/0112477. Bibcode:2002ApJS..141..503N. doi:10.1086/340570. S2CID 51814894.
  7. "HD 140913". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-01-31.
  8. Stefanik, R. P.; et al. (May 1994). The Unseen Companion of HD 140913: Another Brown Dwarf Candidate. American Astronomical Society, 184th AAS Meeting, id.43.07. Bulletin of the American Astronomical Society. 26. p. 931. Bibcode:1994AAS...184.4307S.
  9. Mazeh, Tsevi; et al. (1996). "Spectroscopic Orbits for Three Binaries with Low-Mass Companions and the Distribution of Secondary Masses near the Substellar Limit". The Astrophysical Journal. 466: 415–426. Bibcode:1996ApJ...466..415M. CiteSeerX 10.1.1.30.5905. doi:10.1086/177521.
  10. Nelemans, G.; Tauris, T. M. (July 1998). "Formation of undermassive single white dwarfs and the influence of planets on late stellar evolution". Astronomy and Astrophysics. 335: L85–L88. arXiv:astro-ph/9806011. Bibcode:1998A&A...335L..85N.
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