Astronomy:Eta1 Coronae Australis

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Short description: Star in the constellation Corona Australis


η1 Coronae Australis
Observation data
Equinox J2000.0]] (ICRS)
Constellation Corona Australis
Right ascension  18h 48m 50.49216s[1]
Declination −43° 40′ 48.1977″[1]
Apparent magnitude (V) 5.456[2]
Characteristics
Spectral type A3V[3]
B−V color index +0.13[4]
Astrometry
Radial velocity (Rv)−4.0±4.2[5] km/s
Proper motion (μ) RA: 22.312[1] mas/yr
Dec.: −14.139[1] mas/yr
Parallax (π)10.2735 ± 0.1889[1] mas
Distance317 ± 6 ly
(97 ± 2 pc)
Absolute magnitude (MV)0.84[6]
Details
Radius2.2[7] R
Luminosity57.72[8] L
Surface gravity (log g)4.04[6] cgs
Temperature8371+4692
−444
[9] K
Rotational velocity (v sin i)122.3[10] km/s
Other designations
Database references
SIMBADdata

Eta1 Coronae Australis, Latinized from η1 CrA, is a suspected astrometric binary[11] star system in the constellation of Corona Australis. It is visible to the naked eye as a dim, white-hued point of light with an apparent visual magnitude of 5.456.[2] Parallax measurements put it at a distance of 317 light-years away from the Sun.

The visible component is an A-type main-sequence star with a stellar classification of A3V,[3] which indicates it is generating energy through core hydrogen fusion. It has broad spectrum absorption lines associated with its rotation period, having a projected rotational velocity of 122.3 km/s.[10] The star is radiating 58[8] times the luminosity of the Sun from its photosphere at an effective temperature of 8,371 K.[9]

References

  1. 1.0 1.1 1.2 1.3 1.4 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. Bibcode2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  2. 2.0 2.1 Høg, E. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics 355: L27–L30. Bibcode2000A&A...355L..27H. 
  3. 3.0 3.1 Houk, Nancy (1978). Michigan catalogue of two-dimensional spectral types for the HD stars. 2. Ann Arbor: Dept. of Astronomy, University of Michigan. Bibcode1978mcts.book.....H. 
  4. Johnson, H. L. (1966). "UBVRIJKL Photometry of the Bright Stars". Communications of the Lunar and Planetary Laboratory 4: 99. Bibcode1966CoLPL...4...99J. 
  5. Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters 32 (11): 759–771. doi:10.1134/S1063773706110065. Bibcode2006AstL...32..759G. 
  6. 6.0 6.1 Philip, A. Davis; Egret, D. (1980). "An Analysis of the Hauck / Mermilliod Catalogue of Homgeneous Four-Color Data - Part Two". Astronomy and Astrophysics Supplement 40: 199. Bibcode1980A&AS...40..199P. 
  7. Pasinetti Fracassini, L. E. et al. (February 2001). "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third edition - Comments and statistics". Astronomy and Astrophysics 367 (2): 521–524. doi:10.1051/0004-6361:20000451. Bibcode2001A&A...367..521P. 
  8. 8.0 8.1 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode2012AstL...38..331A. 
  9. 9.0 9.1 Ammons, S. Mark; Robinson, Sarah E.; Strader, Jay; Laughlin, Gregory; Fischer, Debra; Wolf, Aaron (2006). "The N2K Consortium. IV. New Temperatures and Metallicities for More than 100,000 FGK Dwarfs". The Astrophysical Journal 638 (2): 1004–1017. doi:10.1086/498490. Bibcode2006ApJ...638.1004A. 
  10. 10.0 10.1 Díaz, C. G.; González, J. F.; Levato, H.; Grosso, M. (2011). "Accurate stellar rotational velocities using the Fourier transform of the cross correlation maximum". Astronomy & Astrophysics 531: A143. doi:10.1051/0004-6361/201016386. Bibcode2011A&A...531A.143D. 
  11. Eggleton, P. P.; Tokovinin, A. A. (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, Bibcode2008MNRAS.389..869E.