HD 140913

HD 140913

Observation data Epoch J2000      Equinox J2000
Constellation	Corona Borealis
Right ascension	15^h 45^m 07.44910^s[1]
Declination	+28° 28′ 11.7388″[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)	−20.38±0.21[1] km/s
Proper motion (μ)	RA: −87.880 mas/yr[1] Dec.: 37.978 mas/yr[1]
Parallax (π)	20.4949 ± 0.0367 mas[1]
Distance	159.1 ± 0.3 ly (48.79 ± 0.09 pc)
Absolute magnitude (MV)	4.81[2]
Orbit[5]
Period (P)	147.912+0.022 −0.023 d
Semi-major axis (a)	0.561+0.015 −0.016 AU
Eccentricity (e)	0.5223±0.0081
Inclination (i)	30.3±1.3°
Longitude of the node (Ω)	311.0±1.6°
Periastron epoch (T)	2,457,387.33±0.90 JD
Argument of periastron (ω) (secondary)	23.7+2.1 −1.8°
Semi-amplitude (K1) (primary)	2.023±0.073 km/s
Details[5]
Mass	0.987±0.087 M☉
Radius	1.034±0.021 R☉
Luminosity	1.32+0.15 −0.11 L☉
Surface gravity (log g)	4.403+0.042 −0.050 cgs
Temperature	6,090+180 −140 K
Metallicity [Fe/H]	−0.26+0.21 −0.23 dex
Rotational velocity (v sin i)	9.7[2] km/s
Age	7.13[2] Gyr
HD 140913 b
Mass	93.3+1.7 −1.6 MJup
Other designations
BD+28°2469, HD 140913, HIP 77152, SAO 83985[6]
Database references
SIMBAD	data

HD 140913 is a Sun-like star 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 159 light-years from the Sun based on parallax. Prior to the discovery of a companion, this served as an IAU radial velocity standard,[7] and it is receding from the Sun at a rate of +37 km/s.[8] The space velocity components of this star are (U, V, W) = (-21.77, -14.42, 1.67).[3]

Physical characteristics

HD 140913 is a solar-type star[9] with a spectral type of G0V.[3] It is estimated to be 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 as the Sun and 92% of its mass.[2] It is radiating 1.3 times the Sun's luminosity from its photosphere at an effective temperature of 6,090 K.[5]

Companion

The detection of an orbiting companion, designated HD 140913 B, was announced in 1994.[7][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.[11]

In 2023, the true mass of this companion was determined using Gaia astrometry. Two different studies find masses ranging from about 75 to about 93 Jupiter masses, placing this object near the boundary between brown dwarfs and low-mass stars.[12][5]

References

1. Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 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. S2CID 119511744. 21.
3. Montes, D.; et al. (November 2001). "Late-type members of young stellar kinematic groups - I. Single stars". 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. S2CID 55727428.
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. Unger, N.; Ségransan, D.; et al. (December 2023). "Exploring the brown dwarf desert with precision radial velocities and Gaia DR3 astrometric orbits". Astronomy & Astrophysics. 680: A16. arXiv:2310.02758. Bibcode:2023A&A...680A..16U. doi:10.1051/0004-6361/202347578.
6. "HD 140913". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-01-31.
7. 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. Vol. 26. p. 931. Bibcode:1994AAS...184.4307S.
8. 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.
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.
11. 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.
12. Stevenson, Adam T.; Haswell, Carole A.; et al. (December 2023). "Combing the brown dwarf desert with Gaia DR3". Monthly Notices of the Royal Astronomical Society. 526 (4): 5155–5171. arXiv:2310.02695. Bibcode:2023MNRAS.526.5155S. doi:10.1093/mnras/stad3041.