Delta Piscis Austrini
Delta Piscis Austrini (shortened as δ PsA) is a yellow coloured star[1] located in the southern constellation of Piscis Austrinus. It is visible to the naked eye with an apparent magnitude of +4.175.[2] There is a star with an apparent magnitude 9.86[1] located at an angular separation of 5.2 arc seconds, the pair most likely form a binary star system.[3] Using an annual parallax shift of 18.9796 mas as seen from the Gaia satellite, Delta Piscis Austrini is located 172 or 174 light years from the Sun.[4]
  | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Piscis Austrinus |
| Right ascension | 22h 55m 56.90026s[5] |
| Declination | −32° 32′ 22.6335″[5] |
| Apparent magnitude (V) | +4.175[2] (4.18 + 9.86)[1] |
| Characteristics | |
| δ PsA A | |
| Spectral type | G8 III[6] |
| U−B color index | +0.72[2] |
| B−V color index | +0.94[2] |
| δ PsA B | |
| Spectral type | G8 IV[1] |
| U−B color index | +0.77[1] |
| B−V color index | +0.67[1] |
| Astrometry | |
| Radial velocity (Rv) | −11.60[7] km/s |
| Proper motion (μ) | RA: +11.499 ± 0.398[4] mas/yr Dec.: +32.641 ± 0.379[4] mas/yr |
| Parallax (π) | 18.9796 ± 0.2558[4] mas |
| Distance | 172 ± 2 ly (52.7 ± 0.7 pc) |
| Absolute magnitude (MV) | +0.636[8] |
| Details | |
| δ PsA A | |
| Mass | 1.42[7] M☉ |
| Luminosity | 52[7] L☉ |
| Surface gravity (log g) | 2.72±0.10[7] cgs |
| Temperature | 4,828±29[7] K |
| Metallicity [Fe/H] | −0.21±0.10[9] dex |
| Age | 3.74[7] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
The main star of the system is an evolved G-type giant star with a spectral type of G8III.[6] The star is about 3.74 billion years.[7] It is a red clump star, which means it is generating energy through helium fusion at its core.[8] The star has an estimated mass of about 1.42 times the mass of the Sun and it emits luminosity 52 times that of the Sun from its photosphere at an effective temperature of 4,828 K.[7]
The star is orbiting the Galaxy at a speed of 13.8 km/s like the Sun. Its estimated Galactic orbit carries it between 24,048 (periapsis) and 35,430 (apoapsis) light years from the center of the Galaxy.[11]
References
[change | change source]- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Corbally, C. J. (1984), "Close visual binaries. I - MK classifications", Astrophysical Journal Supplement Series, 55: 657, Bibcode:1984ApJS...55..657C, doi:10.1086/190973.
- ↑ 2.0 2.1 2.2 2.3 Rakos, K. D.; et al. (February 1982), "Photometric and astrometric observations of close visual binaries", Astronomy and Astrophysics Supplement Series, 47: 221–235, Bibcode:1982A&AS...47..221R.
- ↑ 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, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
- ↑ 4.0 4.1 4.2 4.3 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.
- ↑ 5.0 5.1 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600.
- ↑ 6.0 6.1 Houk, Nancy (1979), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 3, Ann Arbor, Michigan: Department of Astronomy, University of Michigan, Bibcode:1982mcts.book.....H.
- ↑ 7.0 7.1 7.2 7.3 7.4 7.5 7.6 7.7 Luck, R. Earle (2015), "Abundances in the Local Region. I. G and K Giants", Astronomical Journal, 150 (3), 88, arXiv:1507.01466, Bibcode:2015AJ....150...88L, doi:10.1088/0004-6256/150/3/88, S2CID 118505114.
- ↑ 8.0 8.1 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.
- ↑ Alves, S.; et al. (April 2015), "Determination of the spectroscopic stellar parameters for 257 field giant stars", Monthly Notices of the Royal Astronomical Society, 448 (3): 2749–2765, arXiv:1503.02556, Bibcode:2015MNRAS.448.2749A, doi:10.1093/mnras/stv189, S2CID 119217930.
- ↑ "del PsA -- Star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2017-05-18.
- ↑ 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.