HD 166006, also known as HR 6778, is a solitary orange-hued star located in the southern constellation Telescopium. It has an apparent magnitude of 6.07, making it barely visible to the naked eye. Based on Gaia DR2 parallax measurements, the object is located 582 light years away. It is currently approaching the Solar System with a somewhat constrained heliocentric radial velocity of −15 km/s.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Telescopium |
| Right ascension | 18h 11m 04.40s[1] |
| Declination | −47° 30′ 47.24″[1] |
| Apparent magnitude (V) | 6.07±0.01[2] |
| Characteristics | |
| Spectral type | K1 III CN2[3] |
| B−V color index | +1.20[4] |
| Astrometry | |
| Radial velocity (Rv) | −14.9±2.9[5] km/s |
| Proper motion (μ) | RA: −3.69±0.39 mas/yr[6] Dec.: −29.50±0.23 mas/yr[6] |
| Parallax (π) | 5.6048 ± 0.0652 mas[1] |
| Distance | 582 ± 7 ly (178 ± 2 pc) |
| Absolute magnitude (MV) | −0.12[7] |
| Details | |
| Mass | 1.24[8] M☉ |
| Radius | 20.1[9] R☉ |
| Luminosity | 165[7] L☉ |
| Surface gravity (log g) | 1.89[8] cgs |
| Temperature | 4,529±93[10] K |
| Metallicity [Fe/H] | −0.07[8] dex |
| Rotational velocity (v sin i) | <1[11] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
HD 166006 has a stellar classification of K1 III CN2,[3] which indicates that it is an evolved red giant with a strong overabundance of cyano radicals in its spectrum, making it a CN star. At the estimated distance of HD 166006, the star has an angular diameter of 1.05 mas.[10] This yields a radius of 20.1 R☉.[9] It has 1.24 times the mass of the Sun[8] and radiates 165 times the luminosity of the Sun[7] from its enlarged photosphere at an effective temperature of 4,529 K.[10] The star is slightly metal deficient ([Fe/H] = −0.07[8]) and spins a little too slowly to be accurately measured.[11]HD 166006 has an optical 11th magnitude companion located 1.8" away along a position angle of 271° as of 2015.[13]
References
edit- ^ a b c 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.
- ^ Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (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 Houk, Nancy (1978). Michigan catalogue of two-dimensional spectral types for the HD stars Volume II: Declinations −53° to −40°. Bibcode:1978mcts.book.....H.
- ^ Johnson, H. L.; Mitchell, R. I.; Iriarte, B.; Wisniewski, W. Z. (1966). "UBVRIJKL Photometry of the Bright Stars". Communications of the Lunar and Planetary Laboratory. 4: 99–110. Bibcode:1966CoLPL...4...99J.
- ^ Gontcharov, G. A. (November 2006). "Pulkovo Compilation of Radial Velocities for 35,495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. eISSN 1562-6873. ISSN 1063-7737. S2CID 119231169.
- ^ van Leeuwen, Floor (13 August 2007). "Validation of the new Hipparcos reduction". Astronomy & Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. eISSN 1432-0746. ISSN 0004-6361. Hipparcos record for this source at VizieR.
- ^ a b c 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 d e Anders, F.; et al. (1 August 2019). "Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia DR2 stars brighter than G = 18" (PDF). 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 Stevens, Daniel J.; Stassun, Keivan G.; Gaudi, B. Scott (1 December 2017). "Empirical Bolometric Fluxes and Angular Diameters of 1.6 Million Tycho-2 Stars and Radii of 350,000 Stars with Gaia DR1 Parallaxes". The Astronomical Journal. 154 (6): 259. arXiv:1708.05025. Bibcode:2017AJ....154..259S. doi:10.3847/1538-3881/aa957b. ISSN 0004-6256. S2CID 119191064.
- ^ a b De Medeiros, J. R.; Alves, S.; Udry, S.; Andersen, J.; Nordström, B.; Mayor, M. (1 January 2014). "A catalog of rotational and radial velocities for evolved stars. V. Southern stars". Astronomy and Astrophysics. 561: A126. arXiv:1312.3474. Bibcode:2014A&A...561A.126D. doi:10.1051/0004-6361/201220762. ISSN 0004-6361. S2CID 54046583.
- ^ "HR 6778". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 15 September 2021.
- ^ Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (1 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.
