Astronomy:Chi1 Sagittarii
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| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Sagittarius |
| Right ascension | 19h 25m 16.49013s[1] |
| Declination | −24° 30′ 30.8599″[1] |
| Apparent magnitude (V) | +5.03[2] (5.46 + 5.96)[3] |
| Characteristics | |
| Evolutionary stage | main sequence[4] |
| Spectral type | A3/5 IV/V[5] (A2IV + A5IV) |
| B−V color index | +0.23[2] |
| Astrometry | |
| Radial velocity (Rv) | −43.4±1.6[6] km/s |
| Proper motion (μ) | RA: +61.63[1] mas/yr Dec.: −50.66[1] mas/yr |
| Parallax (π) | 13.25 ± 0.07[3] mas |
| Distance | 246 ± 1 ly (75.5 ± 0.4 pc) |
| Absolute magnitude (MV) | +0.59[7] |
| Orbit[3] | |
| Period (P) | 5.6985±0.0015 yr |
| Semi-major axis (a) | 0.0664±0.0003″ |
| Eccentricity (e) | 0.7099±0.0033 |
| Inclination (i) | 93.02±0.50° |
| Longitude of the node (Ω) | 80.15±0.55° |
| Periastron epoch (T) | B 2023.9455±0.0010 |
| Argument of periastron (ω) (secondary) | 354.19±0.75° |
| Details[3] | |
| Chi1 Sgr A | |
| Mass | 2.09±0.02 M☉ |
| Chi1 Sgr B | |
| Mass | 1.78±0.01 M☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
Chi1 Sagittarii (χ1 Sagittarii) is a binary star[9] system in the zodiac constellation of Sagittarius. The pair have a combined apparent visual magnitude of +5.03,[2] which is bright enough to be seen with the naked eye. Based upon a parallax of 13.25 mas,[3] it is located around 246 light years away. It is advancing through space in the general direction of the Earth with a radial velocity of −43.4 km/s.[6]
This is a visual binary with an orbital period of 5.6985 years, an eccentricity of 0.710, and an angular semimajor axis of 66.4 mas. The magnitude 5.46 primary, Chi1 Sagittarii A, has a mass 2.09 times that of the Sun, while the secondary, Chi1 Sagittarii B, has a mass 1.78 times solar and a magnitude of 5.96. Spectral types of A2IV and A5IV have been published for the primary and secondary component.[3] A spectrum of A3/5 IV/V has been published,[5] but Helmut Abt published spectral type of kA5hF0VmF0, typical of Am stars.[10] This notation indicates it has the calcium K-lines of an A5 star, and the hydrogen and metal lines of an F0 star.
References
- ↑ 1.0 1.1 1.2 1.3 van Leeuwen, Floor. (November 2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. doi:10.1051/0004-6361:20078357. ISSN 0004-6361. Bibcode: 2007A&A...474..653V.
- ↑ 2.0 2.1 2.2 Nicolet, B. (1978), "Photoelectric photometric Catalogue of homogeneous measurements in the UBV System", Astronomy and Astrophysics Supplement Series 34: 1–49, Bibcode: 1978A&AS...34....1N, https://ui.adsabs.harvard.edu/abs/1978A&AS...34....1N.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 Docobo, José Ángel; Campo, Pedro Pablo; Gómez, Jorge; Piccotti, Luca; Caballero-Valdes, Camila; Mendez, Rene A.; Costa, Edgardo (2026-07-31), "22 Orbits of Binaries Based on SOAR Speckle Observations: Systems with Early Type Components", The Astronomical Journal 172 (2): 133, doi:10.3847/1538-3881/ae877f, ISSN 0004-6256.
- ↑ Zorec, J.; Royer, F. (2012). "Rotational velocities of A-type stars. IV. Evolution of rotational velocities". Astronomy and Astrophysics 537: A120. doi:10.1051/0004-6361/201117691. Bibcode: 2012A&A...537A.120Z.
- ↑ 5.0 5.1 Houk, Nancy; Smith-Moore, M. (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, 4, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode: 1988mcts.book.....H, https://ui.adsabs.harvard.edu/abs/1988mcts.book.....H/abstract.
- ↑ 6.0 6.1 Kharchenko, N. V.; Scholz, R.-D.; Piskunov, A. E.; Röser, S.; Schilbach, E. (2007), "Astrophysical supplements to the ASCC-2.5: Ia. Radial velocities of ˜55000 stars and mean radial velocities of 516 Galactic open clusters and associations", Astronomische Nachrichten 328 (9): 889–896, doi:10.1002/asna.200710776, Bibcode: 2007AN....328..889K, https://onlinelibrary.wiley.com/doi/10.1002/asna.200710776.
- ↑ Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ "chi01 Sgr". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=chi01+Sgr.
- ↑ "Sixth Catalog of Orbits of Visual Binary Stars". United States Naval Observatory. April 25, 2016. http://www.usno.navy.mil/USNO/astrometry/optical-IR-prod/wds/orb6. Retrieved 20 June 2017.
- ↑ Abt, H. A. (March 1981), "Visual multiples. VII - MK classifications", Astrophysical Journal Supplement Series 45: 437–456, doi:10.1086/190719, Bibcode: 1981ApJS...45..437A.
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