Astronomy:Beta Indi
| Observation data 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[1] mas |
| Distance | approx. 600 ly (approx. 180 pc) |
| Absolute magnitude (MV) | −2.664[6] |
| Details | |
| Mass | 6.7±0.4[7] M☉ |
| Radius | 55.58+9.35 −5.02[8] R☉ |
| Luminosity | 1,183±58[8] L☉ |
| Surface gravity (log g) | 0.800[9] cgs |
| Temperature | 4,541+220 −334[8] K |
| Metallicity [Fe/H] | −0.06[9] dex |
| Age | 53.2±10.0[7] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
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
- ↑ 1.0 1.1 1.2 1.3 1.4 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode: 2007A&A...474..653V.
- ↑ 2.0 2.1 2.2 2.3 2.4 Anderson, E.; Francis, Ch. (May 2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331–346, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 3.0 3.1 Houk, Nancy (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, 1, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode: 1975mcts.book.....H.
- ↑ 4.0 4.1 Buscombe, W. (1962), "Spectral classification of Southern fundamental stars", Mount Stromlo Observatory Mimeogram 4: 1, Bibcode: 1962MtSOM...4....1B.
- ↑ Hoffleit, D.; Warren, Jr., W. H., "HR 7986, database entry", The Bright Star Catalogue (CDS), http://webviz.u-strasbg.fr/viz-bin/VizieR-5?-out.add=.&-source=V/50/catalog&recno=7986. ID V/50. Accessed on line September 23, 2008.
- ↑ Cassatella, A. et al. (2001), "On the Wilson-Bappu relationship in the Mg II k line", Astronomy and Astrophysics 374 (3): 1085–1091, doi:10.1051/0004-6361:20010816, Bibcode: 2001A&A...374.1085C
- ↑ 7.0 7.1 7.2 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, doi:10.1111/j.1365-2966.2010.17434.x, Bibcode: 2011MNRAS.410..190T
- ↑ 8.0 8.1 8.2 8.3 8.4 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
- ↑ 9.0 9.1 Soubiran, C. et al. (June 2010), "The PASTEL catalogue of stellar parameters", Astronomy and Astrophysics 515: A111, doi:10.1051/0004-6361/201014247, Bibcode: 2010A&A...515A.111S.
- ↑ 10.0 10.1 "bet Ind". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=bet+Ind.
- ↑ Ayres, Thomas R. (January 2005), "X-Rays from Hybrid Stars", The Astrophysical Journal 618 (1): 493–501, doi:10.1086/425891, Bibcode: 2005ApJ...618..493A
- ↑ Mason, B. D. et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal 122 (6): 3466, doi:10.1086/323920, Bibcode: 2001AJ....122.3466M
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