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Beta Coronae Australis

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Beta Coronae Australis
Location of β CrA (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Corona Australis
Right ascension 19h 10m 01.75580s[1]
Declination −39° 20′ 26.8644″[1]
Apparent magnitude (V) 4.10±0.01[2]
Characteristics
Spectral type K0 II/III CN1.5[3]
U−B color index +1.07[4]
B−V color index +1.20[4]
R−I color index +0.61[4]
Astrometry
Radial velocity (Rv)2.7±0.7[5] km/s
Proper motion (μ) RA: +4.37 mas/yr[1]
Dec.: −36.65 mas/yr[1]
Parallax (π)6.88 ± 0.25 mas[1]
Distance470 ± 20 ly
(145 ± 5 pc)
Absolute magnitude (MV)−1.71[6]
Details
Mass5.17±0.26[7] M☉
Radius38.5±1.9[8] R☉
Luminosity614±33[9] L☉
Surface gravity (log g)1.26[10] cgs
Temperature4,575±55[11] K
Metallicity [Fe/H]+0.24[10] dex
Rotational velocity (v sin i)6.2±2[12] km/s
Other designations
β CrA, 46 G. Coronae Australis[13], CD−39°13146, CPD−39°8327, GC 26380, HD 178345, HIP 94160, HR 7259, SAO 211005, PPM 298639[14]
Database references
SIMBADdata

Beta Coronae Australis (Beta CrA), Latinized from β Coronae Australis, is a solitary star[15] located in the southern constellation Corona Australis. It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.10.[2] The star is located around 470 light years distant from the Sun based on parallax,[1] and is drifting further away with a radial velocity of 2.7 km/s.[5] At its current distance, Beta CrA's brightness is diminished by 0.29 magnitudes due to interstellar dust.[16]

Beta CrA has a stellar classification of K0 II/III CN1.5,[3] indicating that it is an evolved K-type star with the blended luminosity class of a bright giant and a regular giant star. The suffix CN1.5 indicates that the object has an anamolous overabundance of cyano radicals in its spectrum, making it a CN star. Having exhausted the supply of hydrogen at its core, the star has expanded to 39 times the Sun's girth.[9] It has 5.17 times the mass of the Sun shines with a luminosity 614 times that of the Sun[9] from its photosphere at a surface temperature of 4,575 K.[11] Beta CrA is metal enriched (174% solar iron abundance[10]) and spins modestly with a projected rotational velocity of 6.2 km/s.[12]

References

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  1. ^ a b c d e van Leeuwen, Floor (13 August 2007). "Validation of the new Hipparcos reduction". Astronomy & Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. eISSN 1432-0746. ISSN 0004-6361. Hipparcos record for this source at VizieR.
  2. ^ a b Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H. ISSN 0004-6361.
  3. ^ a b Houk, N. (1982). Michigan Catalogue of Two-dimensional Spectral Types for the HD stars. Volume III: Declinations −40° to −26°. Bibcode:1982mcts.book.....H.
  4. ^ a b c 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. Bibcode:1966CoLPL...4...99J.
  5. ^ a b Gontcharov, G. A. (November 2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. eISSN 1562-6873. ISSN 1063-7737. S2CID 119231169.
  6. ^ 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. eISSN 1562-6873. ISSN 1063-7737. S2CID 119257644.
  7. ^ Kervella, Pierre; Arenou, Frédéric; Thévenin, Frédéric (2022). "Stellar and substellar companions from Gaia EDR3". Astronomy & Astrophysics. 657: A7. arXiv:2109.10912. Bibcode:2022A&A...657A...7K. doi:10.1051/0004-6361/202142146. eISSN 1432-0746. ISSN 0004-6361.
  8. ^ Kervella, P.; Thévenin, F.; Di Folco, E.; Ségransan, D. (October 2004). "The angular sizes of dwarf stars and subgiants". Astronomy & Astrophysics. 426 (1): 297–307. arXiv:astro-ph/0404180. Bibcode:2004A&A...426..297K. doi:10.1051/0004-6361:20035930. eISSN 1432-0746. ISSN 0004-6361.
  9. ^ a b c 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.
  10. ^ a b c Anders, F.; et al. (August 2019). "Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia DR2 stars brighter than G = 18". Astronomy & Astrophysics. 628: A94. arXiv:1904.11302. Bibcode:2019A&A...628A..94A. doi:10.1051/0004-6361/201935765. eISSN 1432-0746. ISSN 0004-6361.
  11. ^ a b Blackwell, D. E.; Lynas-Gray, A. E. (May 1998). "Determination of the temperatures of selected ISO flux calibration stars using the Infrared Flux Method". Astronomy and Astrophysics Supplement Series. 129 (3): 505–515. Bibcode:1998A&AS..129..505B. doi:10.1051/aas:1998202. eISSN 1286-4846. ISSN 0365-0138.
  12. ^ a b 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. arXiv:1312.3474. Bibcode:2014A&A...561A.126D. doi:10.1051/0004-6361/201220762. eISSN 1432-0746. ISSN 0004-6361.
  13. ^ Gould, Benjamin Apthorp (1878). "Uranometria Argentina : brillantez y posicion de las estrellas fijas, hasta la septima magnitud, comprendidas dentro de cien grados del polo austral : con atlas". Resultados del Observatorio Nacional Argentino. 1. Bibcode:1879RNAO....1.....G.
  14. ^ * bet CrA -- Star, database entry, SIMBAD. Accessed on line September 5, 2008.
  15. ^ 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. arXiv:0806.2878. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x. eISSN 1365-2966. ISSN 0035-8711. S2CID 14878976.
  16. ^ Gontcharov, George A.; Mosenkov, Aleksandr V. (28 September 2017). "Verifying reddening and extinction for Gaia DR1 TGAS main sequence stars". Monthly Notices of the Royal Astronomical Society. 472 (4): 3805–3820. arXiv:1709.01160. Bibcode:2017MNRAS.472.3805G. doi:10.1093/mnras/stx2219. eISSN 1365-2966. ISSN 0035-8711.
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