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]
| 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 | |
| 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
edit- ^ a b c d e f g 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.
- ^ a b c d 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.
- ^ a b 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.
- ^ a b Evans, D. S. (1967). "The Revision of the General Catalogue of Radial Velocities". International Astronomical Union. 30: 57. Bibcode:1967IAUS...30...57E.
- ^ 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.
- ^ a b 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.
- ^ a b c d e 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.
- ^ a b 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.
- ^ 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.
- ^ a b c d 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.
- ^ a b 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.
- ^ 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.
- ^ Evans, D. S. (1966). "Fundamental data for Southern stars (6th list)". Royal Greenwich Observatory Bulletins. 110: 185. Bibcode:1966RGOB..110..185E.
- ^ 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.