97 Aquarii (abbreviated 97 Aqr) is a binary star system in the equatorial constellation of Aquarius. 97 Aquarii is the Flamsteed designation. The combined apparent visual magnitude of the system is 5.20;[2] the brighter star is magnitude 5.59 while the companion is magnitude 6.72.[3] Based upon an annual parallax shift of 15.30 milliarcseconds,[1] this system is at a distance of around 210 light-years (64 parsecs) from Earth.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquarius |
| Right ascension | 23h 22m 39.17113s[1] |
| Declination | –15° 02′ 21.6245″[1] |
| Apparent magnitude (V) | 5.20[2] (5.59/6.72)[3] |
| Characteristics | |
| Spectral type | A2 V + A7 V[4] |
| U−B color index | +0.10[2] |
| B−V color index | +0.20[2] |
| Astrometry | |
| Radial velocity (Rv) | –12[5] km/s |
| Proper motion (μ) | RA: +117.00[1] mas/yr Dec.: +16.48[1] mas/yr |
| Parallax (π) | 15.30 ± 0.79 mas[1] |
| Distance | 210 ± 10 ly (65 ± 3 pc) |
| Orbit[6] | |
| Period (P) | 64.62 yr |
| Semi-major axis (a) | 0.408″ |
| Eccentricity (e) | 0.140 |
| Inclination (i) | 77.6° |
| Longitude of the node (Ω) | 276.3° |
| Periastron epoch (T) | 1941.29 |
| Argument of periastron (ω) (secondary) | 354.6° |
| Details | |
| Rotational velocity (v sin i) | 175[7] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
The two stars in this system orbit each other over a period of 64.62 years at an eccentricity of 0.14.[3] Both are A-type main sequence stars; the primary has a stellar classification of A2 V while its companion is A7 V.[4] Their composite spectrum shows the properties of a Lambda Boötis star, which means it displays peculiar abundances of certain elements.[9]
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 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 c 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 Christy, James W.; Walker, R. L. Jr. (October 1969), "MK Classification of 142 Visual Binaries", Publications of the Astronomical Society of the Pacific, 81 (482): 643, Bibcode:1969PASP...81..643C, doi:10.1086/128831
- ^ 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.
- ^ Anonymous (1999), "New orbits", International Astronomical Union Commission 26 (Double Stars), 139 (Information Circular No. 139): 1–2, Bibcode:1999IAUDS.139....1.
- ^ 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.
- ^ "* 97 Aqr". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2012-07-17.
- ^ Gerbaldi, M.; Faraggiana, R.; Lai, O. (December 2003), "The heterogeneous class of lambda Bootis stars", Astronomy and Astrophysics, 412 (2): 447–464, Bibcode:2003A&A...412..447G, doi:10.1051/0004-6361:20031472.