Astronomy:Lambda Doradus

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Short description: Star in the constellation of Dorado
λ Doradus
Dorado constellation map.svg
Red circle.svg
Location of λ Doradus on the map (circled)
Observation data
Epoch J2000.0   Equinox (celestial coordinates)
Constellation Dorado
Right ascension  05h 26m 19.26577s[1]
Declination −58° 54′ 45.06402″[1]
Apparent magnitude (V) 5.13±0.01[2]
Characteristics
Evolutionary stage red giant branch[3]
Spectral type G6 III[4] or G8 III[5]
B−V color index +1.00[6]
Astrometry
Radial velocity (Rv)10±0.07[7] km/s
Proper motion (μ) RA: −9.792[1] mas/yr
Dec.: +33.350[1] mas/yr
Parallax (π)5.9209 ± 0.0712[1] mas
Distance551 ± 7 ly
(169 ± 2 pc)
Absolute magnitude (MV)−0.6[8]
Details[9]
Mass3.82±0.16 M
Radius21.1±0.5 R
Luminosity252±9 L
Surface gravity (log g)2.41±0.12 cgs
Temperature5,009±43 K
Metallicity [Fe/H]−0.06±0.04 dex
Rotational velocity (v sin i)5.2±1[10] km/s
Age258[11] Myr
Other designations
λ Dor, CPD−59°472, FK5 2410, GC 6749, HD 36189, HIP 25429, HR 1836, SAO 233981[12]
Database references
SIMBADdata

Lambda Doradus (Lambda Dor), Latinized from λ Doradus, is a solitary[13] yellow hued star located in the southern constellation Dorado. It has an apparent magnitude of 5.13,[2] making it faintly visible to the naked eye if viewed under ideal conditions. Parallax measurements place the star at a distance of 551 light years,[1] and it is currently receding with a heliocentric radial velocity of 10 km/s.[7]

Lambda Dor has a stellar classification of either G6[4] or G8 III,[5] depending on the source. Nevertheless, both indicate that it is a red giant, and it is currently on the red giant branch fusing hydrogen in a shell outside a helium core.[3] At present it has 3.82 times the mass of the Sun[9] and at an age of 258 million years, it has expanded to a radius of 21.2 R.[9] It radiates at over 250 times the luminosity of the Sun from its photosphere at an effective temperature of 5,009 K.[9] Lambda Dor is slightly metal deficient, with an iron abundance 12% below solar levels.[9] It currently spins with a projected rotational velocity of 5.2 km/s.[10]

References

  1. 1.0 1.1 1.2 1.3 1.4 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 Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P. et al. (March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics 355: L27–L30. ISSN 0004-6361. Bibcode2000A&A...355L..27H. 
  3. 3.0 3.1 Setiawan, J.; Pasquini, L.; da Silva, L.; von der Lühe, O.; Hatzes, A. (January 2003). "Precise radial velocity measurements of G and K giants". Astronomy & Astrophysics 397 (3): 1151–1159. doi:10.1051/0004-6361:20021559. ISSN 0004-6361. Bibcode2003A&A...397.1151S. 
  4. 4.0 4.1 Houk, N.; Cowley, A. P. (1975). University of Michigan Catalogue of two-dimensional spectral types for the HD stars. Volume I. Declinations −90° to −53°. Bibcode1975mcts.book.....H. 
  5. 5.0 5.1 Keenan, Philip C.; McNeil, Raymond C. (October 1989). "The Perkins catalog of revised MK types for the cooler stars". The Astrophysical Journal Supplement Series 71: 245. doi:10.1086/191373. ISSN 0067-0049. Bibcode1989ApJS...71..245K. 
  6. Johnson, H. L.; Mitchell, R. I.; Iriarte, B.; Wisniewski, W. Z. (1966). "UBVRIJKL Photometry of the Bright Stars". Communications of the Lunar and Planetary Laboratory 4: 99–110. Bibcode1966CoLPL...4...99J. 
  7. 7.0 7.1 Jofré, E.; Petrucci, R.; Saffe, C.; Saker, L.; Artur de la Villarmois, E.; Chavero, C.; Gómez, M.; Mauas, P. J. D. (26 January 2015). "Stellar parameters and chemical abundances of 223 evolved stars with and without planets". Astronomy & Astrophysics 574: A50. doi:10.1051/0004-6361/201424474. ISSN 0004-6361. Bibcode2015A&A...574A..50J. 
  8. Anderson, E.; Francis, Ch. (May 2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331–346. doi:10.1134/S1063773712050015. ISSN 1063-7737. Bibcode2012AstL...38..331A. 
  9. 9.0 9.1 9.2 9.3 9.4 Ottoni, G.; Udry, S.; Ségransan, D.; Buldgen, G.; Lovis, C.; Eggenberger, P.; Pezzotti, C.; Adibekyan, V. et al. (January 2022). "CORALIE radial-velocity search for companions around evolved stars (CASCADES): I. Sample definition and first results: Three new planets orbiting giant stars". Astronomy & Astrophysics 657: A87. doi:10.1051/0004-6361/202040078. ISSN 0004-6361. Bibcode2022A&A...657A..87O. 
  10. 10.0 10.1 De Medeiros, J. R.; Alves, S.; Udry, S.; Andersen, J.; Nordström, B.; Mayor, M. (January 2014). "A catalog of rotational and radial velocities for evolved stars". Astronomy & Astrophysics 561: A126. doi:10.1051/0004-6361/201220762. ISSN 0004-6361. Bibcode2014A&A...561A.126D. 
  11. Gomes da Silva, J.; Santos, N. C.; Adibekyan, V.; Sousa, S. G.; Campante, T. L.; Figueira, P.; Bossini, D.; Delgado-Mena, E. et al. (February 2021). "Stellar chromospheric activity of 1674 FGK stars from the AMBRE-HARPS sample". Astronomy & Astrophysics 646: A77. doi:10.1051/0004-6361/202039765. ISSN 0004-6361. Bibcode2021A&A...646A..77G. 
  12. "lam Dor". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=lam+Dor. 
  13. Eggleton, P. P.; Tokovinin, A. A. (11 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. ISSN 0035-8711. Bibcode2008MNRAS.389..869E. 
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