HD 200661 (HR 8067) is a solitary star in the equatorial constellation Equuleus. It has an apparent magnitude of 6.41, placing it near the max naked eye visibility. The star is situated at a distance of 430 light years[1] but is approaching with a heliocentric radial velocity of −12.1 km/s.[6]
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Equuleus |
| Right ascension | 21h 04m 41.6405s[1] |
| Declination | +02° 56′ 32.1874″[1] |
| Apparent magnitude (V) | 6.41±0.01[2] |
| Characteristics | |
| Evolutionary stage | horizontal branch[3] |
| Spectral type | K0 III[4] |
| U−B color index | +0.89[5] |
| B−V color index | +1.06[5] |
| Astrometry | |
| Radial velocity (Rv) | −12.1 ± 0.2[6] km/s |
| Proper motion (μ) | RA: +13.336[1] mas/yr Dec.: +5.800[1] mas/yr |
| Parallax (π) | 7.5933 ± 0.0353 mas[1] |
| Distance | 430 ± 2 ly (131.7 ± 0.6 pc) |
| Absolute magnitude (MV) | +0.53[7] |
| Details | |
| Mass | 1.74[8] M☉ |
| Radius | 10.62[9] R☉ |
| Luminosity | 51.3[10] L☉ |
| Surface gravity (log g) | 2.1[11] cgs |
| Temperature | 4,740[10] K |
| Metallicity [Fe/H] | −0.1[8] dex |
| Other designations | |
| Database references | |
| SIMBAD | data |
HD 200661 has a stellar classification of K0 III,[4] indicating that the object is an early K-type giant star that is on the horizontal branch.[3] It has an angular diameter of 0.75±0.05 mas, which yields a diameter 10.62[9] times that of the Sun at its estimated distance. At present HD 200661 has 1.74 times the Sun’s mass,[8] and shines at 51.3 times the luminosity of the Sun[10] from its enlarged photosphere at an effective temperature of 4,740 K,[10] giving it a yellow-orange glow.
References
edit- ^ a b c d e f 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.
- ^ Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (1 March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H. ISSN 0004-6361.
- ^ a b Gontcharov, G. A. (November 2008). "Red giant clump in the Tycho-2 catalogue". Astronomy Letters. 34 (11): 785–796. arXiv:1607.00619. Bibcode:2008AstL...34..785G. doi:10.1134/S1063773708110078. ISSN 0004-6299. S2CID 73524157.
- ^ a b Houk, N.; Swift, C. (1999). "Michigan catalogue of two-dimensional spectral types for the HD Stars, Vol. 5". Michigan Spectral Survey. 05: 0. Bibcode:1999MSS...C05....0H.
- ^ a b Cousins, A. W. J. (1971). "Photometric standard stars". Royal Observatory Annals. 7. Bibcode:1971ROAn....7.....C.
- ^ a b Famaey, B.; Jorissen, A.; Luri, X.; Mayor, M.; Udry, S.; Dejonghe, H.; Turon, C. (2005). "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters". Astronomy and Astrophysics. 430: 165. arXiv:astro-ph/0409579. Bibcode:2005A&A...430..165F. doi:10.1051/0004-6361:20041272. S2CID 17804304.
- ^ Anderson, E.; Francis, Ch. (1 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 119257644.
- ^ a b c Anders, F.; et al. (1 August 2019). "Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia DR2 stars brighter than G = 18". Astronomy and Astrophysics. 628: A94. arXiv:1904.11302. Bibcode:2019A&A...628A..94A. doi:10.1051/0004-6361/201935765. ISSN 0004-6361. S2CID 131780028.
- ^ a b Lang, Kenneth R. (2006). Astrophysical formulae. Astronomy and astrophysics library. Vol. 1 (3 ed.). Birkhäuser. ISBN 3-540-29692-1.. The radius (R*) is given by:
- ^ a b c d McDonald, I.; Zijlstra, A. A.; Watson, R. A. (2017). "Fundamental parameters and infrared excesses of Tycho-Gaia stars". Monthly Notices of the Royal Astronomical Society. 471 (1): 770. arXiv:1706.02208. Bibcode:2017MNRAS.471..770M. doi:10.1093/mnras/stx1433.
- ^ Lafrasse, Sylvain; Mella, Guillaume; Bonneau, Daniel; Duvert, Gilles; Delfosse, Xavier; Chesneau, Olivier; Chelli, Alain (16 July 2010). "Building the 'JMMC Stellar Diameters Catalog' using SearchCal". Optical and Infrared Interferometry II. Vol. 7734. pp. 77344E. arXiv:1009.0137. Bibcode:2010SPIE.7734E..4EL. doi:10.1117/12.857024. S2CID 32097037.
- ^ "HR 8067". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 11 September 2021.
