Delta Coronae Australis

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]

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[1] mas
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
SIMBADdata

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]

ReferencesEdit

  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, 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.