51 Aquarii is a binary star[2] system located around 410[1] light years away from the Sun in the equatorial constellation of Aquarius. 51 Aquarii is its Flamsteed designation. It is visible to the naked eye as a dim, yellow-white hued star with a combined apparent visual magnitude of 5.78.[4] The system is moving further from the Earth with a heliocentric radial velocity of +6 km/s.[5]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquarius |
| Right ascension | 22h 24m 06.88433s[1] |
| Declination | –04° 50′ 13.2692″[1] |
| Apparent magnitude (V) | 5.78 (6.45 + 6.63)[2] |
| Characteristics | |
| Spectral type | A0 V[3] + A0[2] |
| U−B color index | –0.11[4] |
| B−V color index | –0.04[4] |
| Astrometry | |
| Radial velocity (Rv) | +6[5] km/s |
| Proper motion (μ) | RA: +26.90[1] mas/yr Dec.: –7.35[1] mas/yr |
| Parallax (π) | 8.04 ± 0.63 mas[1] |
| Distance | 410 ± 30 ly (124 ± 10 pc) |
| Orbit[6] | |
| Period (P) | 145.07±1.85 yr |
| Semi-major axis (a) | 0.402±0.003″ |
| Eccentricity (e) | 0.702±0.003 |
| Inclination (i) | 161.4±0.7° |
| Longitude of the node (Ω) | 113.5±3.0° |
| Periastron epoch (T) | 1987.66±0.05 |
| Argument of periastron (ω) (secondary) | 296.9±3.0° |
| Details | |
| 51 Aqr A | |
| Mass | 2.80±0.10[7] M☉ |
| Luminosity | 88.2+14.8 −14.2[7] L☉ |
| Temperature | 10,328±71[7] K |
| Rotational velocity (v sin i) | 91[7] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
The dual nature of this system was discovered by S. W. Burnham in 1873 with a 6 inches (15 cm) Alvan Clark refractor.[9] The pair orbit each other with a period of 145 years and a large eccentricity of 0.7.[6] The magnitude 6.45[2] primary, designated component A, is an A-type main sequence star with a stellar classification of A0 V.[3] It has a high rate of rotation with a projected rotational velocity of 91 km/s.[10] The secondary component has a matching class of A0 with a visual magnitude of 6.63.[2] It has an effective temperature of 10,238 K.
References
edit- ^ a b c d e f 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 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.
- ^ a b Cowley, A.; et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications", Astronomical Journal, 74: 375–406, Bibcode:1969AJ.....74..375C, doi:10.1086/110819.
- ^ a b c 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.
- ^ a b Wilson, R. E. (1953), "General Catalogue of Stellar Radial Velocities", Carnegie Institute Washington D.C. Publication, Carnegie Institute of Washington, D.C., Bibcode:1953GCRV..C......0W.
- ^ a b Tokovinin, Andrei; Mason, Brian D.; Hartkopf, William I.; Mendez, Rene A.; Horch, Elliott P. (2015), "Speckle Interferometry at Soar in 2014", The Astronomical Journal, 150 (2): 50, arXiv:1506.05718, Bibcode:2015AJ....150...50T, doi:10.1088/0004-6256/150/2/50, S2CID 30737411.
- ^ a b c d Zorec, J.; Royer, F.; Asplund, Martin; Cassisi, Santi; Ramirez, Ivan; Melendez, Jorge; Bensby, Thomas; Feltzing, Sofia (2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy and Astrophysics, 537: A120, arXiv:1201.2052, Bibcode:2012A&A...537A.120Z, doi:10.1051/0004-6361/201117691, S2CID 55586789.
- ^ "* 51 Aqr". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2012-07-16.
- ^ Docobo, J. A.; Ling, J. F. (April 2007), "Orbits and System Masses of 14 Visual Double Stars with Early-Type Components", The Astronomical Journal, 133 (4): 1209–1216, Bibcode:2007AJ....133.1209D, doi:10.1086/511070, S2CID 120821801
- ^ Royer, F.; Zorec, J.; Gómez, A. E. (February 2007), "Rotational velocities of A-type stars. III. Velocity distributions", Astronomy and Astrophysics, 463 (2): 671–682, arXiv:astro-ph/0610785, Bibcode:2007A&A...463..671R, doi:10.1051/0004-6361:20065224, S2CID 18475298.