Delta Coronae Australis

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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]
Distance 174 ± 3  ly
(53.5 ± 0.9  pc)
Absolute magnitude  (MV)0.93 [5]
Details [3]
Mass 1.50±0.01  M
Radius 11.25±0.11  R
Luminosity 53±1  L
Surface gravity (log g)2.59±0.10  cgs
Temperature 4,645±14  K
Metallicity [Fe/H]+0.01±0.10  dex
Age 2.80±0.13  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]

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References

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  2. 1 2 3 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. 1 2 3 4 5 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.
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  5. 1 2 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.
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