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Delta Coronae Australis
Observation data
Epoch J2000.0       Equinox J2000.0 ( ICRS)
Constellation Corona Australis
Right ascension 19h 08m 20.96980s [1]
Declination −40° 29′ 48.1155″ [1]
Apparent magnitude (V) 4.57 [2]
Characteristics
Evolutionary stage horizontal branch [3]
Spectral type K1III [4]
B−V color index +1.070±0.052 [2]
Astrometry
Radial velocity (Rv)+21.24±0.19 [1] km/s
Proper motion (μ) RA: +47.344 [1]  mas/ yr
Dec.: −27.047 [1]  mas/ yr
Parallax (π)18.6963 ± 0.3123  mas [1]
Distance174 ± 3  ly
(53.5 ± 0.9  pc)
Absolute magnitude (MV)0.93 [5]
Details
Mass1.50±0.01 [3]  M
Radius11.37+0.23
−0.65
[1]  R
Luminosity54.7±1.1 [1]  L
Surface gravity (log g)2.59±0.10 [3]  cgs
Temperature4,654+139
−45
[1]  K
Metallicity [Fe/H]+0.01±0.10 [3]  dex
Age2.80±0.13 [3]  Gyr
Other designations
δ CrA, CD−40°13061, HD 177873, HIP 94005, HR 7242, SAO 229513 [6]
Database references
SIMBAD data

Delta Coronae Australis is a single [7] star located in the southern constellation of Corona Australis. It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.57. [2] The star is located about 174  light years from the Sun based on parallax, and is drifting further away with a radial velocity of +21 km/s. [1]

This object is an evolved giant star with a stellar classification of K1III. [4] After exhausting the supply of hydrogen at its core, the star expanded off the main sequence and now has 11 [1] times the radius of the Sun. It is a red clump giant, [3] [5] which indicates it is on the horizontal branch and is generating energy through core helium fusion. The star is 2.8 [3] billion years old with 1.5 [3] times the mass of the Sun. It is radiating 55 [1] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,654 K. [1]

References

  1. ^ a b c d e f g h i j k l m 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.
  2. ^ a b c Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv: 1108.4971. Bibcode: 2012AstL...38..331A. doi: 10.1134/S1063773712050015. S2CID  119257644.
  3. ^ a b c d e f g h Gallenne, A.; et al. (August 2018). "Fundamental properties of red-clump stars from long-baseline H-band interferometry". Astronomy & Astrophysics. 616: 12. arXiv: 1806.09572. Bibcode: 2018A&A...616A..68G. doi: 10.1051/0004-6361/201833341. S2CID  119331707. A68.
  4. ^ a b Houk, Nancy (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 2, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode: 1978mcts.book.....H.
  5. ^ a b Liu, Y. J.; et al. (2007). "The abundances of nearby red clump giants". Monthly Notices of the Royal Astronomical Society. 382 (2): 553–66. Bibcode: 2007MNRAS.382..553L. doi: 10.1111/j.1365-2966.2007.11852.x.
  6. ^ "del CrA". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-08-20.
  7. ^ Eggleton, P. P.; Tokovinin, A. A. (2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society. 389 (2): 869. arXiv: 0806.2878. Bibcode: 2008MNRAS.389..869E. doi: 10.1111/j.1365-2966.2008.13596.x. S2CID  14878976.