HD 89571

HD 89571 (HR 4062) is a binary star^[12] located in the northern circumpolar constellation Camelopardalis. It is faintly visible to the naked eye with a combined apparent magnitude of 5.51^[2] and is estimated to be 142 light years^[1] away from the Solar System. However, it is receding with a heliocentric radial velocity of 3.5 km/s.^[4]

HD 89571

Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Camelopardalis
Right ascension	10h 29m 41.6297s[1]
Declination	+84° 15′ 06.949″[1]
Apparent magnitude (V)	5.51±0.01[2]
Characteristics
Spectral type	A9 V[3]
U−B color index	+0.06[2]
B−V color index	+0.23[2]
Astrometry
Radial velocity (Rv)	3.5±2[4] km/s
Proper motion (μ)	RA: −145.145 mas/yr[1] Dec.: −21.494 mas/yr[1]
Parallax (π)	23.0490 ± 0.3729 mas[1]
Distance	142 ± 2 ly (43.4 ± 0.7 pc)
Absolute magnitude (MV)	+2.48[5]
Orbit[6]
Primary	A
Companion	B
Period (P)	2.20±0.03 yr
Semi-major axis (a)	0.0142±0.0006″
Eccentricity (e)	0.26±0.11
Details
A
Mass	1.69[7] M☉
Radius	1.79[1] R☉
Luminosity	8.4[8] L☉
Surface gravity (log g)	4.27[9] cgs
Temperature	7,535[10] K
Metallicity [Fe/H]	+0.04[11] dex
Rotational velocity (v sin i)	134±7[10] km/s
Age	710[7] Myr
B
Mass	0.38[7] M☉
Other designations
AG+84°229, BD+84°234, GC 14305, HD 89571, HIP 51384, HR 4062, SAO 1701, WDS J10297+8415AB
Database references
SIMBAD	data

The primary has a stellar classification of A9 V,^[3] indicating that it is an ordinary A-type main-sequence star. David S. Evans gave it a slightly warmer class of A6 V^[13] while Cowley et al. classified it as F0 IV,^[14] indicating a F-type subgiant. Nevertheless, the two components take roughly 2 years to orbit each other at a mean separation of 14.2 mas.^[6]

The components have masses of 1.69 M_☉ and 0.38 M_☉,^[7] with the latter being a probable M-type star. HD 89571 has a radius of 1.79 R_☉^[1] and a luminosity of 8.4 L_☉.^[8] This yields an effective temperature of 7,535 K,^[10] giving a white hue. It is estimated to be 710 million years old^[7] and spins rapidly with a projected rotational velocity of 134 km/s;^[10] it has a near solar metallicity, equating to an iron abundance 110% that of the Sun.^[11]

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. Oja, T. (August 1991). "UBV photometry of stars whose positions are accurately known. VI". Astronomy and Astrophysics Supplement Series. 89: 415. Bibcode:1991A&AS...89..415O. ISSN 0365-0138.
3. Abt, Helmut A.; Morrell, Nidia I. (July 1995). "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars". The Astrophysical Journal Supplement Series. 99: 135. Bibcode:1995ApJS...99..135A. doi:10.1086/192182. ISSN 0067-0049.
4. Evans, D. S. (1967). "The Revision of the General Catalogue of Radial Velocities". International Astronomical Union. 30: 57. Bibcode:1967IAUS...30...57E.
5. 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.
6. Malkov, O. Yu.; Tamazian, V. S.; Docobo, J. A.; Chulkov, D. A. (October 2012). "Dynamical masses of a selected sample of orbital binaries". Astronomy & Astrophysics. 546: A69. Bibcode:2012A&A...546A..69M. doi:10.1051/0004-6361/201219774. eISSN 1432-0746. ISSN 0004-6361.
7. De Rosa, R. J.; Patience, J.; Wilson, P. A.; Schneider, A.; Wiktorowicz, S. J.; Vigan, A.; Marois, C.; Song, I.; Macintosh, B.; Graham, J. R.; Doyon, R.; Bessell, M. S.; Thomas, S.; Lai, O. (26 November 2013). "The VAST Survey – III. The multiplicity of A-type stars within 75 pc". Monthly Notices of the Royal Astronomical Society. 437 (2): 1216–1240. arXiv:1311.7141. Bibcode:2014MNRAS.437.1216D. doi:10.1093/mnras/stt1932. eISSN 1365-2966. ISSN 0035-8711.
8. Chandler, Colin Orion; McDonald, Iain; Kane, Stephen R. (17 February 2016). "The Catalog of Earth-Like Exoplanet Survey Targets (CELESTA): A Database of Habitable Zones Around Nearby Stars". The Astronomical Journal. 151 (3): 59. arXiv:1510.05666. Bibcode:2016AJ....151...59C. doi:10.3847/0004-6256/151/3/59. eISSN 1538-3881.
9. Allende Prieto, C.; Lambert, D. L. (December 1999). "Fundamental parameters of nearby stars from the comparison with evolutionary calculations: masses, radii and effective temperatures". Astronomy and Astrophysics. 352: 555–562. arXiv:astro-ph/9911002. Bibcode:1999A&A...352..555A. ISSN 0004-6361.
10. Reiners, A. (January 2006). "Rotation- and temperature-dependence of stellar latitudinal differential rotation". Astronomy & Astrophysics. 446 (1): 267–277. arXiv:astro-ph/0509399. Bibcode:2006A&A...446..267R. doi:10.1051/0004-6361:20053911. eISSN 1432-0746. ISSN 0004-6361.
11. Netopil, Martin (4 May 2017). "Metallicity calibrations for dwarf stars and giants in the Geneva photometric system". Monthly Notices of the Royal Astronomical Society. 469 (3): 3042–3055. arXiv:1705.00883. Bibcode:2017MNRAS.469.3042N. doi:10.1093/mnras/stx1077. eISSN 1365-2966. ISSN 0035-8711.
12. Eggleton, P. P.; Tokovinin, A. A. (11 September 2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society. 389 (2): 869–879. arXiv:0806.2878. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x. eISSN 1365-2966. ISSN 0035-8711.
13. Evans, D. S. (1966). "Fundamental data for Southern stars (6th list)". Royal Greenwich Observatory Bulletins. 110: 185. Bibcode:1966RGOB..110..185E.
14. Cowley, A.; Cowley, C.; Jaschek, M.; Jaschek, C. (April 1969). "A study of the bright stars. I. A catalogue of spectral classifications". The Astronomical Journal. 74: 375. Bibcode:1969AJ.....74..375C. doi:10.1086/110819. ISSN 0004-6256.