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]
| 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 | |
| Mass | 1.50±0.01[3] M☉ |
| Radius | 11.37+0.23 −0.65[1] R☉ |
| Luminosity | 54.7±1.1[1] L☉ |
| Surface gravity (log g) | 2.59±0.10[3] cgs |
| Temperature | 4,654+139 −45[1] K |
| Metallicity [Fe/H] | +0.01±0.10[3] dex |
| Age | 2.80±0.13[3] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
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
- ^ 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.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ "del CrA". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-08-20.
- ^ 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.