Rho Draconis
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Draco |
| Right ascension | 20h 02m 49.07268s[1] |
| Declination | +67° 52′ 24.8294″[1] |
| Apparent magnitude (V) | 4.52[2] |
| Characteristics | |
| Spectral type | K3 III[3] |
| U−B color index | +1.54[2] |
| B−V color index | +1.34[2] |
| Astrometry | |
| Radial velocity (Rv) | −9.80±0.43[4] km/s |
| Proper motion (μ) | RA: +16.44[1] mas/yr Dec.: +47.31[1] mas/yr |
| Parallax (π) | 7.61±0.17 mas [1] |
| Distance | 429 ± 10 ly (131 ± 3 pc) |
| Absolute magnitude (MV) | −0.97[5] |
| Details | |
| Radius | 28[3] R☉ |
| Luminosity | 402[6] L☉ |
| Surface gravity (log g) | 1.90[7] cgs |
| Temperature | 4370[7] K |
| Metallicity [Fe/H] | 0.03[7] dex |
| Rotational velocity (v sin i) | 10[8] km/s |
| Other designations | |
| ρ Dra , 67 Dra , BD+67° 1222, HD 190940, HIP 98702, HR 7685, SAO 18676[9] | |
| Database references | |
| SIMBAD | data |
Rho Draconis (ρ Draconis) is a solitary[10] star in the northern circumpolar constellation of Draco. It is faintly visible to the naked eye with an apparent visual magnitude of 4.52.[2] Based upon an annual parallax shift of 7.61 mas as measured from Earth,[1] it is located around 429 light years from the Sun. At that distance, the visual magnitude of the star is diminished by an extinction factor of 0.027 due to interstellar dust.[5]
With a stellar classification of K3 III,[3] Rho Draconis is a normal giant star that is past the first dredge-up phase of its post-main sequence evolution.[7] It has the peculiar spectrum of a CN star, showing abnormal line strengths for cyanogen and calcium.[11] The star has expanded to around 28[3] times the Sun's radius and it is radiating 402[6] times the solar luminosity from its photosphere at an effective temperature of 4,370 K.[7]
References
[edit ]- ^ a b c d e f van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752 , Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600.
- ^ a b c d Argue, A. N. (1966), "UBV photometry of 550 F, G and K type stars", Monthly Notices of the Royal Astronomical Society , 133 (4): 475–493, Bibcode:1966MNRAS.133..475A, doi:10.1093/mnras/133.4.475 .
- ^ a b c d Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics, 367 (3rd ed.): 521–524, arXiv:astro-ph/0012289 , Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451, S2CID 425754.
- ^ Famaey, B.; et al. (2005), "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters", Astronomy and Astrophysics, 430: 165–186, arXiv:astro-ph/0409579 , Bibcode:2005A&A...430..165F, doi:10.1051/0004-6361:20041272, S2CID 17804304.
- ^ a b Ryon, Jenna; et al. (August 2009), "Comparing the Ca ii H and K Emission Lines in Red Giant Stars", Publications of the Astronomical Society of the Pacific, 121 (882): 842, arXiv:0907.3346 , Bibcode:2009PASP..121..842R, doi:10.1086/605456, S2CID 17821279.
- ^ a b McDonald, I.; et al. (2012), "Fundamental parameters and infrared excesses of Hipparcos stars", Monthly Notices of the Royal Astronomical Society, 427 (1): 343–357, arXiv:1208.2037 , Bibcode:2012MNRAS.427..343M, doi:10.1111/j.1365-2966.2012.21873.x , S2CID 118665352.
- ^ a b c d e Mishenina, T. V.; et al. (October 1995), "Chemical composition of five giants with positive CN-indices.", Astronomy and Astrophysics Supplement, 113: 333, Bibcode:1995A&AS..113..333M.
- ^ Bernacca, P. L.; Perinotto, M. (1970), "A catalogue of stellar rotational velocities", Contributi Osservatorio Astronomico di Padova in Asiago, 239 (1): 1, Bibcode:1970CoAsi.239....1B.
- ^ "rho Dra". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2017年05月30日.
- ^ Eggleton, P. P.; Tokovinin, A. A. (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 . S2CID 14878976.
- ^ Mishenina, T. V.; Tsymbal, V. V. (September 1997), "Li and CNO abundances in the atmospheres of nine peculiar giants", Astronomy Letters, 23 (5): 609–614, Bibcode:1997AstL...23..609M.