Astronomy:Rho Draconis
| Observation data 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[1] mas |
| 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 | |
| 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
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode: 2007A&A...474..653V.
- ↑ 2.0 2.1 2.2 2.3 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, doi:10.1093/mnras/133.4.475, Bibcode: 1966MNRAS.133..475A.
- ↑ 3.0 3.1 3.2 3.3 Pasinetti Fracassini, L. E. et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics 367: 521–524, doi:10.1051/0004-6361:20000451, Bibcode: 2001A&A...367..521P.
- ↑ 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, doi:10.1051/0004-6361:20041272, Bibcode: 2005A&A...430..165F.
- ↑ 5.0 5.1 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, doi:10.1086/605456, Bibcode: 2009PASP..121..842R.
- ↑ 6.0 6.1 McDonald, I. et al. (2012), "Fundamental parameters and infrared excesses of Hipparcos stars", Monthly Notices of the Royal Astronomical Society 427 (1): 343–357, doi:10.1111/j.1365-2966.2012.21873.x, Bibcode: 2012MNRAS.427..343M.
- ↑ 7.0 7.1 7.2 7.3 7.4 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. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=rho+Dra.
- ↑ 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. doi:10.1111/j.1365-2966.2008.13596.x. Bibcode: 2008MNRAS.389..869E.
- ↑ 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.
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