Wikipedia
94 Aquarii
94 Aquarii (abbreviated 94 Aqr) is a triple star[12] system in the equatorial constellation of Aquarius. 94 Aquarii is the Flamsteed designation. The brightest member has an apparent visual magnitude of 5.19,[2] making it visible to the naked eye. The parallax measured by the Gaia spacecraft yields a distance estimate of around 73 light-years (22 parsecs) from Earth.[1]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquarius |
| 94 Aquarii A (Aa/Ab) | |
| Right ascension | 23h 19m 06.7257s[1] |
| Declination | –13° 27′ 31.6146″[1] |
| Apparent magnitude (V) | 5.19[2] |
| 94 Aquarii B | |
| Right ascension | 23h 19m 06.5609s[3] |
| Declination | –13° 27′ 18.9037″[3] |
| Apparent magnitude (V) | 7.52[2] |
| Characteristics | |
| 94 Aqr A | |
| Spectral type | G8.5 IV[4] + K V[5] |
| U−B color index | +0.42[2] |
| B−V color index | +0.79[2] |
| 94 Aqr B | |
| Spectral type | K2 V[4] |
| U−B color index | +0.60[2] |
| B−V color index | +0.88[2] |
| Astrometry | |
| 94 Aquarii A (Aa/Ab) | |
| Radial velocity (Rv) | +17.60±0.07[6] km/s |
| Proper motion (μ) | RA: 258.738±0.944[1] mas/yr Dec.: −73.014±0.928[1] mas/yr |
| Parallax (π) | 44.8996 ± 0.5572 mas[1] |
| Distance | 72.6 ± 0.9 ly (22.3 ± 0.3 pc) |
| Absolute magnitude (MV) | +3.52/+6.52[7] |
| 94 Aquarii B | |
| Proper motion (μ) | RA: 306.702±0.107[3] mas/yr Dec.: −104.633±0.086[3] mas/yr |
| Parallax (π) | 44.5152 ± 0.0550 mas[3] |
| Distance | 73.27 ± 0.09 ly (22.46 ± 0.03 pc) |
| Absolute magnitude (MV) | +5.92[7] |
| Orbit[7] | |
| Primary | 94 Aquarii Aa |
| Companion | 94 Aquarii Ab |
| Period (P) | 6.321±0.010 yr |
| Semi-major axis (a) | 0.189±0.002″ |
| Eccentricity (e) | 0.173±0.020 |
| Inclination (i) | 44.5±1.0° |
| Longitude of the node (Ω) | 341.9±1.5° |
| Periastron epoch (T) | 2012.301 |
| Argument of periastron (ω) (secondary) | 28.3° |
| Details | |
| 94 Aquarii Aa | |
| Mass | 1.22±0.03[8] M☉ |
| Radius | 2.06±0.03[8] R☉ |
| Luminosity | 3.30±0.06[8] L☉ |
| Surface gravity (log g) | 3.88[9] cgs |
| Temperature | 5,461[9] K |
| Metallicity [Fe/H] | +0.23[9] dex |
| Rotational velocity (v sin i) | 8[10] km/s |
| Age | 6.2±0.2[8] Gyr |
| 94 Aquarii Ab | |
| Mass | 0.81±0.04[8] M☉ |
| Radius | 0.85±0.03[8] R☉ |
| Temperature | 4,670 or 4,970[5] K |
| 94 Aquarii B | |
| Surface gravity (log g) | 4.54[5] cgs |
| Temperature | 5,136[5] K |
| Metallicity [Fe/H] | +0.24[5] dex |
| Other designations | |
| Database references | |
| SIMBAD | data |
The inner pair of this triple star system form a spectroscopic binary with an orbital period of 6.321 years, a moderate orbital eccentricity of 0.173,[7] and a combined visual magnitude of 5.19.[13] The primary component of this pair has a stellar classification of G8.5 IV,[9] with the luminosity class of IV indicating this is a subgiant star. At an angular separation of 13.0 arcseconds from this pair is a magnitude 7.52[13] K-type main sequence star with a classification of K2 V.[4]
References edit
- ^ a b c d e f 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 c d e f g 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 d e 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 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 c d e Fuhrmann, Klaus (February 2008). "Nearby stars of the Galactic disc and halo - IV". Monthly Notices of the Royal Astronomical Society. 384 (1): 173–224. Bibcode:2008MNRAS.384..173F. doi:10.1111/j.1365-2966.2007.12671.x.
- ^ Katoh, Noriyuki; et al. (2013). "Determination of Orbital Elements of Spectroscopic Binaries Using High-dispersion Spectroscopy". The Astronomical Journal. 145 (2). 41. Bibcode:2013AJ....145...41K. doi:10.1088/0004-6256/145/2/41.
- ^ a b c d Docobo, José A.; et al. (2018). "Visual Orbit and Individual Masses of the Single-lined Spectroscopic Binary 94 AQR A (HD 219834A; MCA 74)". The Astronomical Journal. 156 (3). 85. Bibcode:2018AJ....156...85D. doi:10.3847/1538-3881/aad179.
- ^ a b c d e f Metcalfe, Travis S.; van Saders, Jennifer L.; Basu, Sarbani; Buzasi, Derek; Chaplin, William J.; Egeland, Ricky; Garcia, Rafael A.; Gaulme, Patrick; Huber, Daniel; Reinhold, Timo; Schunker, Hannah; Stassun, Keivan G.; Appourchaux, Thierry; Ball, Warrick H.; Bedding, Timothy R.; Deheuvels, Sébastien; González-Cuesta, Lucía; Handberg, Rasmus; Jiménez, Antonio; Kjeldsen, Hans; Li, Tanda; Lund, Mikkel N.; Mathur, Savita; Mosser, Benoit; Nielsen, Martin B.; Noll, Anthony; Çelik Orhan, Zeynep; Örtel, Sibel; Santos, Ângela R. G.; Yildiz, Mutlu; Baliunas, Sallie; Soon, Willie (11 September 2020). "The Evolution of Rotation and Magnetic Activity in 94 Aqr Aa from Asteroseismology with TESS". The Astrophysical Journal. 900 (2): 154. arXiv:2007.12755. Bibcode:2020ApJ...900..154M. doi:10.3847/1538-4357/aba963.
- ^ a b c d Gray, R. O.; et al. (July 2006), "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 parsecs: The Northern Sample I", The Astronomical Journal, 132 (1): 161–170, arXiv:astro-ph/0603770, Bibcode:2006AJ....132..161G, doi:10.1086/504637, S2CID 119476992.
- ^ Bernacca, P. L.; Perinotto, M. (1970), "A catalogue of stellar rotational velocities", Contributi Osservatorio Astronomico di Padova in Asiago, 239 (1): 1, Bibcode:1970CoAsi.239....1B.
- ^ "* 94 Aqr". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2012-07-17.
- ^ Sarma, M. B. K. (January 1962), "The Orbit of the Spectroscopic Binary 94 Aquarii", Astrophysical Journal, 135: 301, Bibcode:1962ApJ...135..301S, doi:10.1086/147268.
- ^ a b 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.
External links edit
- Image 94 Aquarii