Rho Draconis

Rho Draconis
Location of ρ Draconis (circled in red)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Draco
Right ascension 20h 02m 49.07085s[1]
Declination +67° 52′ 24.8308″[1]
Apparent magnitude (V) 4.52[2]
Characteristics
Evolutionary stage red giant branch[1]
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: +15,824[1] mas/yr
Dec.: +47.749[1] mas/yr
Parallax (π)7.5052±0.0993 mas[1]
Distance435 ± 6 ly
(133 ± 2 pc)
Absolute magnitude (MV)−0.97[5]
Details
Radius28[3] R☉
Luminosity402[6] L☉
Surface gravity (log g)1.90[7] cgs
Temperature4370[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
SIMBADdata

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. Based upon an annual parallax shift of 7.5 mas as measured from Earth, it is located around 435 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. ^ 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.
  2. ^ a b c 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.
  3. ^ 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.
  4. ^ 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.
  5. ^ 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.
  6. ^ 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.
  7. ^ 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.
  8. ^ 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.
  9. ^ "rho Dra". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-05-30.
  10. ^ 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.
  11. ^ 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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