Beta Doradus

From the Science Archives, the open-project database of science information
Jump to navigation Jump to search

β Doradus
Diagram showing star positions and boundaries of the Dorado constellation and its surroundings
Cercle rouge 100%.svg
Location of β Doradus (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Dorado
Right ascension 05h 33m 37.51729s[1]
Declination −62° 29′ 23.3692″[1]
Apparent magnitude (V) 3.63[2]
Spectral type F4-G4Ia-II[3]
U−B color index +0.55[3]
B−V color index +0.70[2]
R−I color index +0.48[2]
Variable type δ Cephei[4]
Radial velocity (Rv)+7.2[5] km/s
Proper motion (μ) RA: +0.79[1] mas/yr
Dec.: +12.74[1] mas/yr
Parallax (π)3.14 ± 0.16[6] mas
Distance1,040 ± 50 ly
(320 ± 20 pc)
Absolute magnitude (MV)−3.91 ± 0.11[7]
Mass6.5[8] M
Radius67.8 ± 0.7[9] R
Diameter67.8 ± 0.7[9] D
Luminosity3,200[7] L
Surface gravity (log g)1.3[10] cgs
Temperature5,445[7] K
Metallicity [Fe/H]–0.13[10] dex
Rotational velocity (v sin i)0[3] km/s
Other designations
β Dor, Beta Doradus, Beta Dor, CD−62 214, CPD−62 487, FK5 212, GC 6944, HD 37350, HIP 26069, HR 1922, PPM 354837, SAO 249311.[11]
Database references

Beta Doradus (Beta Dor, β Doradus, β Dor) is the second brightest star in the southern constellation of Dorado.[8] It has an apparent visual magnitude of 3.63,[2] making it visible to the naked eye from the southern hemisphere. Based upon parallax measurements with the Hubble Space Telescope, it is located at a distance of 1,040 light-years (320 parsecs) from Earth.[6]

Beta Doradus is a Cepheid variable that regularly changes magnitude from a low of 4.05 to a high of 3.45 over a period of 9.842 days.[12] The light curve of this magnitude change follows a regular saw-tooth pattern.[13] During each radial pulsation cycle, the radius of the star varies by ±3.9 times the Sun's radius around a mean of 67.8.[9] Its spectral type and luminosity class are likewise variable, from F-type to G-type and from a supergiant to a bright giant.[3]

Far ultraviolet emissions have been detected from this star with the Far Ultraviolet Spectroscopic Explorer, while X-ray emissions were detected with the XMM-Newton space telescope. The X-ray luminosity is about 1 × 1029 erg/s and the emission varies with the pulsation period, suggesting a connection with the pulsation process. The peak X-ray emissions are in the 0.6–0.8 keV energy range, which occurs for plasmas with temperatures of 7–10 million K.[13]


  1. 1.0 1.1 1.2 1.3 van Leeuwen, F. (November 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
  2. 2.0 2.1 2.2 2.3 Turner, D. G. (April 1980), "The reddening of Beta Doradus", Journal of the Royal Astronomical Society of Canada 74: 64–69, Bibcode 1980JRASC..74...64T
  3. 3.0 3.1 3.2 3.3 HR 1922, database entry, The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version), D. Hoffleit and W. H. Warren, Jr., CDS ID V/50. Accessed on line September 9, 2008.
  4. bet Dor, database entry, The combined table of GCVS Vols I-III and NL 67-78 with improved coordinates, General Catalogue of Variable Stars, Sternberg Astronomical Institute, Moscow, Russia. Accessed on line September 9, 2008.
  5. Evans, D. S. (June 20–24, 1966), Batten, Alan Henry; Heard, John Frederick, eds., The Revision of the General Catalogue of Radial Velocities, University of Toronto: International Astronomical Union, Bibcode 1967IAUS...30...57E
  6. 6.0 6.1 McArthur, Barbara E. et al. (May 2011), "Astrometry with the Hubble Space Telescope: Trigonometric Parallaxes of Selected Hyads", The Astronomical Journal 141 (5): 172, arXiv:1103.2094, Bibcode 2011AJ....141..172M, doi:10.1088/0004-6256/141/5/172
  7. 7.0 7.1 7.2 Turner, David G. (April 2010), "The PL calibration for Milky Way Cepheids and its implications for the distance scale", Astrophysics and Space Science 326 (2): 219–231, arXiv:0912.4864, Bibcode 2010Ap&SS.326..219T, doi:10.1007/s10509-009-0258-5
  8. 8.0 8.1 Kaler, James B., "Beta Doradus", Stars (University of Illinois),, retrieved 2012-01-01
  9. 9.0 9.1 Taylor, Melinda M.; Booth, Andrew J. (August 1998), "The bright southern Cepheid beta Doradus: the radial velocity curve, distance and size", Monthly Notices of the Royal Astronomical Society 298 (2): 594–600, Bibcode 1998MNRAS.298..594T, doi:10.1046/j.1365-8711.1998.01670.x
  10. 10.0 10.1 Romaniello, M. et al. (September 2008), "The influence of chemical composition on the properties of Cepheid stars. II. The iron content", Astronomy and Astrophysics 488 (2): 731–747, arXiv:0807.1196, Bibcode 2008A&A...488..731R, doi:10.1051/0004-6361:20065661
  11. Lua error in Module:Citation/CS1 at line 379: attempt to call method 'match' (a nil value).
  12. Klagyivik, P.; Szabados, L. (September 2009), "Observational studies of Cepheid amplitudes. I. Period-amplitude relationships for Galactic Cepheids and interrelation of amplitudes", Astronomy and Astrophysics 504 (3): 959–972, arXiv:0908.3561, Bibcode 2009A&A...504..959K, doi:10.1051/0004-6361/200811464
  13. 13.0 13.1 Engle, Scott G. et al. (May 2009), "The Secret XUV Lives of Cepheids: FUV/X-ray observations of Polaris and β Dor", Future Directions in Ultraviolet Spectroscopy: A Conference Inspired by the Accomplishments of the Far Ultraviolet Spectroscopic Explorer Mission, AIP Conference Proceedings, 1135, pp. 192–197, arXiv:0902.3449, Bibcode 2009AIPC.1135..192E, doi:10.1063/1.3154048

Add your comment
The Science Archives welcomes all comments. If you do not want to be anonymous, register or log in. It is free.

As a reminder, article comments are only for discussions on how to improve the article. Please direct other comments to a user's talk page. Please be formal and do not use excessive uppercase. Please be advised you may receive an automatic block if you break the article comments policy. For information regarding what is acceptable/not acceptable in article comments, please message Icons-flag-ru.png Joey (talk), Natalia (talk), Icons-flag-fr.png ynoss (talk), or Icons-flag-ca.png Daniel (older account/talk).