HD 85725

HD 85725, also known as HR 3916, is a yellow hued star located in the southern constellation Antlia. It has an apparent magnitude of 6.29,^[2] placing it near the limit for naked eye visibility. The object is relatively close at a distance of 176 light-years,^[1] but is receding with a heliocentric radial velocity of 61.6 km/s.^[5]

HD 85725

Observation data Epoch J2000      Equinox J2000
Constellation	Antlia
Right ascension	09h 52m 58.02763s[1]
Declination	−27° 19′ 55.8219″[1]
Apparent magnitude (V)	6.28[2]
Characteristics
Spectral type	G1 V[3]
B−V color index	+0.62[4]
Astrometry
Radial velocity (Rv)	61.6±0.1[5] km/s
Proper motion (μ)	RA: −278.245 mas/yr[1] Dec.: +95.043 mas/yr[1]
Parallax (π)	18.5634 ± 0.0256 mas
Distance	175.7 ± 0.2 ly (53.87 ± 0.07 pc)
Absolute magnitude (MV)	+2.68[2]
Details
Mass	1.42[6] M☉
Radius	2.59±0.11[7] R☉
Luminosity	7.58[8] L☉
Surface gravity (log g)	3.86[9] cgs
Temperature	5,940±110[7] K
Metallicity [Fe/H]	+0.15[10] dex
Rotational velocity (v sin i)	5.9±0.3[11] km/s
Age	2.75[6] Gyr
Other designations
33 G. Antliae, CD−26° 7505, CPD−26°4079, HIP 48468, HR 3916, SAO 178130, WDS J09530-2720A[12]
Database references
SIMBAD	data

HD 85725 has a stellar classification of G1 V,^[3] which indicates that it is an ordinary G-type main-sequence star that is fusing hydrogen at its core. However, a low surface gravity of 7244 cm/s^2[9] suggests that the object is instead an evolved subgiant.

At present it has 143%^[6] the mass of the Sun but is 2.59 times larger,^[7] which is not characteristic of a yellow dwarf. It shines at 7.6^[8] times the luminosity of the Sun from its photosphere at a surface temperature of 5,940 K,^[7] which gives it a yellow glow. At an age of 2.75 billion years,^[6] HD 85725 is spinning leisurely with a projected rotational velocity of 5.9 km/s.^[11]

There is a 10th magnitude companion located 1.5″ away along a position angle of 25°. It appears to have a common proper motion with the star, suggesting physical relation.^[13]

References

1. Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
2. Anderson, E.; Francis, Ch. (May 2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331–346. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. ISSN 1063-7737. S2CID 255204555.
3. Houk, N. (1982). Michigan Catalogue of Two-dimensional Spectral Types for the HD stars. Volume_3. Declinations -40_ƒ0 to -26_ƒ0. Bibcode:1982mcts.book.....H.
4. Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data. Bibcode:1986EgUBV........0M.
5. Nidever, David L.; Marcy, Geoffrey W.; Butler, R. Paul; Fischer, Debra A.; Vogt, Steven S. (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. eISSN 1538-4365. ISSN 0067-0049.
6. "BaSTI Home Page". basti.oa-abruzzo.inaf.it.
7. Stassun, Keivan G.; et al. (9 September 2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal. 158 (4): 138. arXiv:1905.10694. Bibcode:2019AJ....158..138S. doi:10.3847/1538-3881/ab3467. eISSN 1538-3881.
8. McDonald, I.; Zijlstra, A. A.; Watson, R. A. (October 2017). "Fundamental parameters and infrared excesses of Tycho-Gaia stars". Monthly Notices of the Royal Astronomical Society. 471 (1): 770–791. arXiv:1706.02208. Bibcode:2017MNRAS.471..770M. doi:10.1093/mnras/stx1433. ISSN 0035-8711.
9. Costa Silva, A. R.; Delgado Mena, E.; Tsantaki, M. (February 2020). "Chemical abundances of 1111 FGK stars from the HARPS-GTO planet search sample. III. Sulfur". Astronomy and Astrophysics. 634: A136. arXiv:1912.08659. Bibcode:2020A&A...634A.136C. doi:10.1051/0004-6361/201936523. ISSN 0004-6361.
10. Delgado Mena, E.; Adibekyan, V.; Santos, N. C.; Tsantaki, M.; González Hernández, J. I.; Sousa, S. G.; Bertrán de Lis, S. (November 2021). "Chemical abundances of 1111 FGK stars from the HARPS GTO planet search program". Astronomy & Astrophysics. 655: A99. arXiv:2109.04844. Bibcode:2021A&A...655A..99D. doi:10.1051/0004-6361/202141588. eISSN 1432-0746. ISSN 0004-6361. S2CID 237485512.
11. Saar, S. H.; Osten, R. A. (1 February 1997). "Rotation, turbulence and evidence for magnetic fields in southern dwarfs". Monthly Notices of the Royal Astronomical Society. 284 (4): 803–810. Bibcode:1997MNRAS.284..803S. doi:10.1093/mnras/284.4.803. eISSN 1365-2966. ISSN 0035-8711.
12. "HD 85725". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 22 August 2017.
13. Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (December 2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal. 122 (6): 3466–3471. Bibcode:2001AJ....122.3466M. doi:10.1086/323920. ISSN 0004-6256.