Psi Sagittarii, which is Latinized from ψ Sagittarii, is a triple star[8] system in the zodiac constellation of Sagittarius. The star system is located at a distance of 298 light years from the Earth based on parallax, but is drifting closer with a heliocentric radial velocity of −12 km/s.[4] The system is faintly visible to the naked eye has a combined apparent visual magnitude of +4.86.[2]
 | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Sagittarius |
| Right ascension | 19h 15m 32.42658s[1] |
| Declination | −25° 15′ 24.0569″[1] |
| Apparent magnitude (V) | +4.86[2] |
| Characteristics | |
| Spectral type | K2 III + A9 III + A3 V[3] |
| B−V color index | 0.569±0.006[2] |
| Astrometry | |
| Radial velocity (Rv) | −11.43±1.47[4] km/s |
| Proper motion (μ) | RA: +45.50[1] mas/yr Dec.: −31.08[1] mas/yr |
| Parallax (π) | 10.93 ± 0.31 mas[1] |
| Distance | 298 ± 8 ly (91 ± 3 pc) |
| Absolute magnitude (MV) | 0.06[2] |
| Orbit[5] | |
| Period (P) | 7,319 d |
| Eccentricity (e) | 0.51 |
| Periastron epoch (T) | 2442418.795 JD |
| Argument of periastron (ω) (secondary) | 2.6° |
| Semi-amplitude (K1) (primary) | 10.0 km/s |
| Semi-amplitude (K2) (secondary) | 13.8 km/s |
| Details | |
| A | |
| Mass | 2.10[6] M☉ |
| Luminosity | 84[2] L☉ |
| Ba/Bb | |
| Mass | 1.70/2.70 M☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
The inner pair of this triple star system, components Ba and Bb, have an orbital period of 10.78 days and an eccentricity of 0.47.[8] The pair consist of an A-type giant and a less evolved A-type main-sequence star with stellar classifications of A9 III + A3 V,[3] respectively. These in turn share an orbit with the primary, component A, having a period of 20 years and an eccentricity of 0.51.[5] The last is an orange-hued K-type giant with a class of K2 III.[3]
Name and etymology
editAccording to the catalogue of stars in the Technical Memorandum 33-507 - A Reduced Star Catalog Containing 537 Named Stars, this star was titled as Al Kiladah.[9] This star, together with τ Sgr, ν Sgr, ω Sgr, 60 Sgr and ζ Sgr were Al Udḥiyy, the Ostrich's Nest.[10]
References
edit- ^ a b c d e 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.
- ^ a b c d e 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 Docobo, José A.; Andrade, Manuel (November 2006), "A Methodology for the Description of Multiple Stellar Systems with Spectroscopic Subcomponents", The Astrophysical Journal, 652 (1): 681–695, Bibcode:2006ApJ...652..681D, doi:10.1086/508053.
- ^ a b 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 Pourbaix, D.; Tokovinin, A. A.; Batten, A. H.; Fekel, F. C.; Hartkopf, W. I.; et al. (2004), "SB9: The ninth catalogue of spectroscopic binary orbits", Astronomy & Astrophysics, 424 (2): 727–732, arXiv:astro-ph/0406573, Bibcode:2004A&A...424..727P, doi:10.1051/0004-6361:20041213, S2CID 119387088.
- ^ Tokovinin, A. (September 2008), "Comparative statistics and origin of triple and quadruple stars", Monthly Notices of the Royal Astronomical Society, 389 (2): 925–938, arXiv:0806.3263, Bibcode:2008MNRAS.389..925T, doi:10.1111/j.1365-2966.2008.13613.x, S2CID 16452670.
- ^ "psi Sgr". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-07-02.
- ^ a b 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.
- ^ Rhoads, Jack W. (November 15, 1971), Technical Memorandum 33-507-A Reduced Star Catalog Containing 537 Named Stars (PDF), California Institute of Technology: Jet Propulsion Laboratory, retrieved 2017-07-02.
- ^ Allen, R. H. (1963). Star Names: Their Lore and Meaning (Reprint ed.). New York: Dover Publications Inc. p. 355. ISBN 0-486-21079-0. Retrieved 2012-09-04.
External links
edit- Kaler, James B. (November 4, 2016), "Psi Sagittarii", STARS.