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Beta Indi

Beta Indi
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Indus
Right ascension 20h 54m 48.60278s[1]
Declination −58° 27′ 14.9618″[1]
Apparent magnitude (V) 3.67[2]
Characteristics
Spectral type K1II[3] or K0III[4]
U−B color index +1.23[5]
B−V color index +1.250±0.015[2]
Astrometry
Radial velocity (Rv)−4.9±0.7[2] km/s
Proper motion (μ) RA: 21.06[1] mas/yr
Dec.: −24.75[1] mas/yr
Parallax (π)5.41 ± 0.73 mas[1]
Distanceapprox. 600 ly
(approx. 180 pc)
Absolute magnitude (MV)−2.664[6]
Details
Mass6.7±0.4[7] M☉
Radius55.58+9.35
−5.02[8] R☉
Luminosity1,183±58[8] L☉
Surface gravity (log g)0.800[9] cgs
Temperature4,541+220
−334[8] K
Metallicity [Fe/H]−0.06[9] dex
Age53.2±10.0[7] Myr
Other designations
B 2847A, β Ind, CD−58°7788, FK5 785, HD 198700, HIP 103227, HR 7986, SAO 246784, WDS 20548-5827A[10]
Database references
SIMBADdata

Beta Indi, Latinized from β Indi, is the second brightest star in the southern constellation of Indus.[10] It is visible to the naked eye as a faint, orange-hued point of light with an apparent visual magnitude of 3.67.[2] The star is located approximately 600 light years from the Sun, based on parallax, but is drifting closer with a radial velocity of −5 km/s.[2]

The stellar classification of this star is K1II,[3] matching an evolved bright giant. Earlier it had been categorized as an ordinary giant with a class of K0III.[4] It is a hybrid giant with both a hot stellar corona and cool stellar winds, and is a weak X-ray source with a flux measured at (11±1)×10−14 ergs cm−1 s−1.[11] Having consumed the supply of hydrogen at its core, this star has expanded off the main sequence and now has about 56[8] times the girth of the Sun. It is 53 million years old with 6.7 times the mass of the Sun.[7] The star is radiating 1,183 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,541 K.[8]

β Indi has a visual companion, CCDM J20548-5827B, with an apparent visual magnitude of approximately 12.5. As of 2015, it lies at an angular separation of 17.2″ along a position angle of 100° from the brighter component.[12]

References

  1. ^ a b c d e van Leeuwen, F. (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, S2CID 18759600.
  2. ^ a b c d e Anderson, E.; Francis, Ch. (May 2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331–346, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
  3. ^ a b Houk, Nancy (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 1, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode:1975mcts.book.....H.
  4. ^ a b Buscombe, W. (1962), "Spectral classification of Southern fundamental stars", Mount Stromlo Observatory Mimeogram, 4: 1, Bibcode:1962MtSOM...4....1B.
  5. ^ Hoffleit, D.; Warren, Jr., W. H., "HR 7986, database entry", The Bright Star Catalogue (5th Revised Ed. (Preliminary Version) ed.), CDS. ID V/50. Accessed on line September 23, 2008.
  6. ^ Cassatella, A.; et al. (2001), "On the Wilson-Bappu relationship in the Mg II k line", Astronomy and Astrophysics, 374 (3): 1085–1091, arXiv:astro-ph/0106070, Bibcode:2001A&A...374.1085C, doi:10.1051/0004-6361:20010816, S2CID 16286422
  7. ^ a b c Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M. (January 2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society, 410 (1): 190–200, arXiv:1007.4883, Bibcode:2011MNRAS.410..190T, doi:10.1111/j.1365-2966.2010.17434.x, S2CID 118629873
  8. ^ a b c d e Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  9. ^ a b Soubiran, C.; et al. (June 2010), "The PASTEL catalogue of stellar parameters", Astronomy and Astrophysics, 515: A111, arXiv:1004.1069, Bibcode:2010A&A...515A.111S, doi:10.1051/0004-6361/201014247, S2CID 118362423.
  10. ^ a b "bet Ind". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-08-20.
  11. ^ Ayres, Thomas R. (January 2005), "X-Rays from Hybrid Stars", The Astrophysical Journal, 618 (1): 493–501, Bibcode:2005ApJ...618..493A, doi:10.1086/425891, S2CID 123363660
  12. ^ Mason, B. D.; et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal, 122 (6): 3466, Bibcode:2001AJ....122.3466M, doi:10.1086/323920
Quelle: https://en.wikipedia.org/wiki/Beta_Indi