57 Aquilae (abbreviated 57 Aql) is a double star in the constellation of Aquila. 57 Aquilae is its Flamsteed designation. The primary star has an apparent visual magnitude of 5.70, while the secondary is magnitude 6.48.[2] The pair have an angular separation of 35.624 arcseconds and probably form a wide binary star system.[7] The estimated distance of the first component is 480 light-years (150 parsecs), while the second is at 510 light-years (160 parsecs). However, the margin of errors for their respective distance estimates overlap,[1] indicating a probability that they are actually located much closer to each other. Both stars are massive, B-type main sequence stars with rapid rotation rates.[3]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquila |
| 57 Aql A | |
| Right ascension | 19h 54m 37.65152s[1] |
| Declination | –08° 13′ 38.2390″[1] |
| Apparent magnitude (V) | 5.70[2] |
| 57 Aql B | |
| Right ascension | 19h 54m 38.06165s[1] |
| Declination | –08° 14′ 13.3762″[1] |
| Apparent magnitude (V) | 6.48[2] |
| Characteristics | |
| Spectral type | B7 Vn + B8 V[3] |
| U−B color index | –0.49/–0.27[2] |
| B−V color index | –0.08/–0.04[2] |
| Astrometry | |
| 57 Aql A | |
| Radial velocity (Rv) | –6[4] km/s |
| Proper motion (μ) | RA: +6.61[1] mas/yr Dec.: –25.75[1] mas/yr |
| Parallax (π) | 6.76 ± 0.37 mas[1] |
| Distance | 480 ± 30 ly (148 ± 8 pc) |
| 57 Aql B | |
| Radial velocity (Rv) | –5[4] km/s |
| Proper motion (μ) | RA: +2.13 mas/yr Dec.: –30.77 mas/yr |
| Parallax (π) | 6.42 ± 0.58 mas[1] |
| Distance | 510 ± 50 ly (160 ± 10 pc) |
| Details | |
| 57 Aql A | |
| Rotational velocity (v sin i) | 190[3] km/s |
| 57 Aql B | |
| Rotational velocity (v sin i) | 160[3] km/s |
| Other designations | |
| 57 Aql A: BD–08 5154, HD 188293, HIP 97966, HR 7593, SAO 143898.[5] | |
| 57 Aql B: BD–08 5155, HD 188294, HIP 97967, HR 7594, SAO 143899.[6] | |
| Database references | |
| SIMBAD | 57 Aql |
| 57 Aql A | |
| 57 Aql B | |
References edit
- ^ a b c d e f g h i van Leeuwen, F. (November 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 Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99): 99, Bibcode:1966CoLPL...4...99J.
- ^ a b c d Abt, Helmut A.; Levato, Hugo; Grosso, Monica (July 2002), "Rotational Velocities of B Stars", The Astrophysical Journal, 573 (1): 359–365, Bibcode:2002ApJ...573..359A, doi:10.1086/340590.
- ^ a b Wilson, Ralph Elmer (1953), "General Catalogue of Stellar Radial Velocities", Carnegie Institute Washington D.C. Publication, Washington: Carnegie Institution of Washington, Bibcode:1953GCRV..C......0W.
- ^ "HR 7593 -- Star in double system", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2012-07-25.
- ^ "HR 7594 -- Star in double system", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2012-07-25.
- ^ 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.
External links edit
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