Astronomy:94 Aquarii

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Short description: Triple star system in the constellation Aquarius
94 Aquarii
Observation data
{{#ifeq:J2000|J2000.0 (ICRS)|Epoch J2000.0      Equinox J2000.0 (ICRS)| Epoch J2000      [[Astronomy:Equinox (celestial coordinates)|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[1] mas
Distance72.6 ± 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[3] mas
Distance73.27 ± 0.09 ly
(22.46 ± 0.03 pc)
Absolute magnitude (MV)+5.92[7]
Orbit[7]
Primary94 Aquarii Aa
Companion94 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
Mass1.22±0.03[8] M☉
Radius2.06±0.03[8] R☉
Luminosity3.30±0.06[8] L☉
Surface gravity (log g)3.88[9] cgs
Temperature5,461[9] K
Metallicity [Fe/H]+0.23[9] dex
Rotational velocity (v sin i)8[10] km/s
Age6.2±0.2[8] Gyr
94 Aquarii Ab
Mass0.81±0.04[8] M☉
Radius0.85±0.03[8] R☉
Temperature4,670 or 4,970[5] K
94 Aquarii B
Surface gravity (log g)4.54[5] cgs
Temperature5,136[5] K
Metallicity [Fe/H]+0.24[5] dex
Other designations
BD−14 6448, GJ 894.2, HD 219834, HIP 115126, HR 8866, SAO 165625[11]
Database references
SIMBADdata

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]

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

  1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  2. ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 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. 
  3. ↑ 3.0 3.1 3.2 3.3 3.4 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  4. ↑ 4.0 4.1 4.2 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, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E. 
  5. ↑ 5.0 5.1 5.2 5.3 5.4 Fuhrmann, Klaus (February 2008). "Nearby stars of the Galactic disc and halo - IV". Monthly Notices of the Royal Astronomical Society 384 (1): 173–224. doi:10.1111/j.1365-2966.2007.12671.x. Bibcode: 2008MNRAS.384..173F. 
  6. ↑ Katoh, Noriyuki et al. (2013). "Determination of Orbital Elements of Spectroscopic Binaries Using High-dispersion Spectroscopy". The Astronomical Journal 145 (2): 41. doi:10.1088/0004-6256/145/2/41. Bibcode: 2013AJ....145...41K. 
  7. ↑ 7.0 7.1 7.2 7.3 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. doi:10.3847/1538-3881/aad179. Bibcode: 2018AJ....156...85D. 
  8. ↑ 8.0 8.1 8.2 8.3 8.4 8.5 Metcalfe, Travis S.; van Saders, Jennifer L.; Basu, Sarbani; Buzasi, Derek; Chaplin, William J.; Egeland, Ricky; Garcia, Rafael A.; Gaulme, Patrick et al. (11 September 2020). "The Evolution of Rotation and Magnetic Activity in 94 Aqr Aa from Asteroseismology with TESS". The Astrophysical Journal 900 (2): 154. doi:10.3847/1538-4357/aba963. Bibcode: 2020ApJ...900..154M. 
  9. ↑ 9.0 9.1 9.2 9.3 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, doi:10.1086/504637, Bibcode: 2006AJ....132..161G. 
  10. ↑ 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. 
  11. ↑ "* 94 Aqr". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=%2A+94+Aqr. 
  12. ↑ Sarma, M. B. K. (January 1962), "The Orbit of the Spectroscopic Binary 94 Aquarii", Astrophysical Journal 135: 301, doi:10.1086/147268, Bibcode: 1962ApJ...135..301S. 
  13. ↑ 13.0 13.1 van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode: 2007A&A...474..653V.