| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Draco |
| Right ascension | 12h 34m 44.01929s[1] |
| Declination | +70° 01′ 18.4053″[1] |
| Apparent magnitude (V) | 4.95[2] |
| Characteristics | |
| Evolutionary stage | red giant branch[1] |
| Spectral type | K2.5 III Fe-2[3] + A8–9 V[4] |
| B−V color index | 1.312±0.003[2] |
| Astrometry | |
| Radial velocity (Rv) | 3.38±0.30[2] km/s |
| Proper motion (μ) | RA: −32.393[1] mas/yr Dec.: −4.449[1] mas/yr |
| Parallax (π) | 6.6159±0.4238 mas[1] |
| Distance | 490 ± 30 ly (151 ± 10 pc) |
| Absolute magnitude (MV) | −1.35[2] |
| Orbit[4] | |
| Period (P) | 561.7±0.3 d |
| Eccentricity (e) | 0.262±0.017 |
| Periastron epoch (T) | 45525±5 MJD |
| Argument of periastron (ω) (secondary) | 9±4° |
| Semi-amplitude (K1) (primary) | 6.90±0.12 km/s |
| Details | |
| Mass | 1.28[5] M☉ |
| Radius | 33[6] R☉ |
| Luminosity | 316[6] L☉ |
| Surface gravity (log g) | 1.43[7] cgs |
| Temperature | 4,134[7] K |
| Metallicity [Fe/H] | −0.22[5] dex |
| Rotational velocity (v sin i) | 1.7[8] km/s |
| Age | 2.2[7] Gyr |
| Other designations | |
| 6 Dra, BD+70°705, HD 109551, HIP 61384, HR 4795, SAO 7600[9] | |
| Database references | |
| SIMBAD | data |
6 Draconis is a single-lined spectroscopic binary[4] star system in the northern constellation of Draco, located about 430 light years away from the Sun. It is visible to the naked eye as an orange-hued star with an apparent visual magnitude of 4.95.[2] The system is moving further from the Earth with a heliocentric radial velocity of 3 km/s.[2]
The variable radial velocity of this star system was announced by W. W. Campbell in 1922. Griffin et al. (1990) found an orbital period of 1.5 yr and an eccentricity of 0.26. The primary has an "a sin i" value of 51.4 Gm (0.34 AU), where a is the semimajor axis and i is the (unknown) orbital inclination. This value provides a lower bound on the actual semimajor axis, which is one half of the longest dimension of their elliptical orbit.[4]
The visible component is an evolved giant star with a stellar classification of K2.5 III Fe-2,[3] where the suffix notation indicates a pronounced underabundance of iron in the spectrum. The measured angular diameter of this star, after correction for limb darkening, is 2.54±0.04 mas.[10] At its estimated distance, this yields a physical size of about 33 times the radius of the Sun.[6] It is radiating 316 times the Sun's luminosity[6] from its enlarged photosphere at an effective temperature of 4,134 K.[7] The companion is most likely an A-type main-sequence star with a class of A8–9 V.[4]
References
[edit]- ^ a b c d e f Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ a b c d e f 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 Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series, 71: 245, Bibcode:1989ApJS...71..245K, doi:10.1086/191373.
- ^ a b c d e Griffin, R. F.; et al. (June 1990), "The spectroscopic orbit of 6 Draconis", Journal of Astrophysics and Astronomy, 11 (2): 255, Bibcode:1990JApA...11..255G, doi:10.1007/BF02715020, S2CID 120297735
- ^ a b Khalatyan, A.; Anders, F.; Chiappini, C.; Queiroz, A. B. A.; Nepal, S.; Dal Ponte, M.; Jordi, C.; Guiglion, G.; Valentini, M.; Torralba Elipe, G.; Steinmetz, M.; Pantaleoni-González, M.; Malhotra, S.; Jiménez-Arranz, Ó.; Enke, H.; Casamiquela, L.; Ardèvol, J. (2024). "Transferring spectroscopic stellar labels to 217 million Gaia DR3 XP stars with SHBoost". Astronomy & Astrophysics. 691: A98. arXiv:2407.06963. Bibcode:2024A&A...691A..98K. doi:10.1051/0004-6361/202451427.
- ^ a b c d Fetherolf, Tara; Pepper, Joshua; Simpson, Emilie; Kane, Stephen R.; Močnik, Teo; English, John Edward; Antoci, Victoria; Huber, Daniel; Jenkins, Jon M.; Stassun, Keivan; Twicken, Joseph D.; Vanderspek, Roland; Winn, Joshua N. (2023), "Variability Catalog of Stars Observed during the TESS Prime Mission", The Astrophysical Journal Supplement Series, 268 (1): 4, arXiv:2208.11721, Bibcode:2023ApJS..268....4F, doi:10.3847/1538-4365/acdee5.
- ^ a b c d Kordopatis, G.; et al. (2023). "Stellar ages, masses, extinctions, and orbital parameters based on spectroscopic parameters of Gaia DR3". Astronomy and Astrophysics. 669: A104. arXiv:2206.07937. Bibcode:2023A&A...669A.104K. doi:10.1051/0004-6361/202244283.
- ^ De Medeiros, J. R.; et al. (October 2002), "The Rotation of Binary Systems with Evolved Components", The Astrophysical Journal, 578 (2): 943–950, arXiv:astro-ph/0207288, Bibcode:2002ApJ...578..943D, doi:10.1086/342613, S2CID 16196039.
- ^ "6 Dra". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-01-23.
- ^ Richichi, A.; Percheron, I.; Khristoforova, M. (February 2005), "CHARM2: An updated Catalog of High Angular Resolution Measurements", Astronomy and Astrophysics, 431 (2): 773–777, Bibcode:2005A&A...431..773R, doi:10.1051/0004-6361:20042039.
