Astronomy:Gamma Doradus

From HandWiki
Short description: Star in the constellation Dorado
Gamma Doradus
Location of γ Doradus (circled in red)
Observation data
Equinox J2000.0]] (ICRS)
Constellation Dorado
Right ascension  04h 16m 01.58662s[1]
Declination −51° 29′ 11.9327″[1]
Apparent magnitude (V) 4.25[2]
Characteristics
Evolutionary stage Main sequence[1]
Spectral type F1V[3]
U−B color index +0.03[4]
B−V color index +0.30[4]
R−I color index +0.16[4]
Variable type γ Dor[2]
Astrometry
Radial velocity (Rv)+25.2±0.5[5] km/s
Proper motion (μ) RA: +100.502[1] mas/yr
Dec.: +184.180[1] mas/yr
Parallax (π)48.9494 ± 0.1689[1] mas
Distance66.6 ± 0.2 ly
(20.43 ± 0.07 pc)
Absolute magnitude (MV)2.72[2]
Details
Mass1.56±0.06[6] M
Radius1.67±0.07[7] R
Luminosity6.52±0.25[7] L
Surface gravity (log g)4.19±0.09[7] cgs
Temperature7,139±132[7] K
Metallicity [Fe/H]+0.05±0.14[8] dex
Rotational velocity (v sin i)56.6±0.5[9] km/s
Age0.535–1.207[6] Gyr
Other designations
γ Dor, CD−51°1066, CPD−51°524, FK5 157, GC 5179, GJ 167.1, HD 27290, HIP 19893, HR 1338, SAO 233457, PPM 333343[10]
Database references
SIMBADdata

Gamma Doradus, Latinized from γ Doradus, is the third-brightest star in the southern constellation of Dorado.[11] It is faintly visible to the naked eye with an apparent visual magnitude of approximately 4.25, and is a variable star, the prototype of the class of Gamma Doradus variables.[2] The star is located at a distance of 67 light-years from the Sun based on parallax,[1] and is drifting further away with a radial velocity of +25 km/s.[5] Based on its motion through space, it appears to be a member of the IC 2391 supercluster.[12]

A light curve for Gamma Doradus, plotted from TESS data[13]

This is an F-type main-sequence star with a stellar classification of F1V.[3] It is a pulsating variable that varies in brightness by less than a tenth of a magnitude owing to nonradial gravity wave oscillations.[2] Four pulsation frequencies have been identified with periods of 17.6, 12.8, 16.3, and 18.2 hours.[9][14] The star is around 0.5–1.2 billion years old and is spinning with a projected rotational velocity of 57 km/s.[9] It has 1.6 times the mass of the Sun[6] and 1.7 times the Sun's radius.[7] The star is radiating 6.5 times the luminosity of the Sun from its photosphere at an effective temperature of 7,139 K.[7]

An infrared excess has been detected at multiple frequencies,[15] indicating that the star is being orbited by a pair of debris disks.[16]

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940  Gaia DR3 record for this source at VizieR.
  2. 2.0 2.1 2.2 2.3 2.4 Kaye, Anthony B. et al. (July 1999). "Gamma Doradus Stars: Defining a New Class of Pulsating Variables". Publications of the Astronomical Society of the Pacific 111 (761): 840–844. doi:10.1086/316399. Bibcode1999PASP..111..840K. 
  3. 3.0 3.1 Gray, R. O. et al. (2006). "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 pc-The Southern Sample". The Astronomical Journal 132 (1): 161–170. doi:10.1086/504637. Bibcode2006AJ....132..161G. 
  4. 4.0 4.1 4.2 Hoffleit, D.; Warren, W. H. Jr.. "HR 1338, database entry". The Bright Star Catalogue. http://webviz.u-strasbg.fr/viz-bin/VizieR-5?-out.add=.&-source=V/50/catalog&recno=1338.  "V/50". CDS. http://vizier.u-strasbg.fr/viz-bin/Cat?V/50. 
  5. 5.0 5.1 Gontcharov, G. A. (November 2006). "Pulkovo Compilation of Radial Velocities for 35495 Hipparcos stars in a common system". Astronomy Letters 32 (11): 759–771. doi:10.1134/S1063773706110065. Bibcode2006AstL...32..759G. 
  6. 6.0 6.1 6.2 Esposito, Thomas M. et al. (July 2020). "Debris Disk Results from the Gemini Planet Imager Exoplanet Survey's Polarimetric Imaging Campaign". The Astronomical Journal 160 (1): 44. doi:10.3847/1538-3881/ab9199. 24. Bibcode2020AJ....160...24E. 
  7. 7.0 7.1 7.2 7.3 7.4 7.5 Stassun, Keivan G. et al. (2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal 158 (4): 138. doi:10.3847/1538-3881/ab3467. Bibcode2019AJ....158..138S. 
  8. Bruntt, H. et al. (February 2008). "A spectroscopic study of southern (candidate) γ Doradus stars. II. Detailed abundance analysis and fundamental parameters". Astronomy and Astrophysics 478 (2): 487–496. doi:10.1051/0004-6361:20078523. Bibcode2008A&A...478..487B. 
  9. 9.0 9.1 9.2 Brunsden, E. et al. (April 2018). "Frequency and mode identification of γ Doradus from photometric and spectroscopic observations*". Monthly Notices of the Royal Astronomical Society 475 (3): 3813–3822. doi:10.1093/mnras/sty034. Bibcode2018MNRAS.475.3813B. 
  10. "gam Dor". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=gam+Dor. 
  11. Kaler, James B.. "Gamma Dor". Stars. http://stars.astro.illinois.edu/sow/gammador.html. 
  12. Eggen, Olin J. (December 1995). "Reality Tests of Superclusters in the Young Disk Population". Astronomical Journal 110: 2862. doi:10.1086/117734. Bibcode1995AJ....110.2862E. 
  13. "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. https://mast.stsci.edu/portal/Mashup/Clients/Mast/Portal.html. 
  14. Balona, L. A.; Krisciunas, K.; Cousins, A. W. J. (October 15, 1994). "γ Doradus: evidence for a new class of pulsating star". Monthly Notices of the Royal Astronomical Society 270 (4): 905–913. doi:10.1093/mnras/270.4.905. Bibcode1994MNRAS.270..905B. 
  15. Broekhoven-Fiene, Hannah et al. (January 2013). "The Debris Disk around γ Doradus Resolved with Herschel". The Astrophysical Journal 762 (1): 11. doi:10.1088/0004-637X/762/1/52. 52. Bibcode2013ApJ...762...52B. 
  16. Greaves, J. S. et al. (February 2014). "Alignment in star-debris disc systems seen by Herschel". Monthly Notices of the Royal Astronomical Society: Letters 438 (1): L31–L35. doi:10.1093/mnrasl/slt153. Bibcode2014MNRAS.438L..31G.