94 Aquarii

94 Aquarii (abbreviated 94 Aqr) is a triple star[11] 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]

94 Aquarii
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[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
Mass1.07±0.06[7] M
Surface gravity (log g)3.88[8] cgs
Temperature5,461[8] K
Metallicity [Fe/H]+0.23[8] dex
Rotational velocity (v sin i)8[9] km/s
94 Aquarii Ab
Mass0.80±0.04[7] M
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[10]
Database references
SIMBADdata

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.[12] The primary component of this pair has a stellar classification of G8.5 IV,[8] 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[12] K-type main sequence star with a classification of K2 V.[4]

See also

References

  1. 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.
  2. 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. 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.
  4. 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.
  5. 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.
  6. 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.
  7. 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.
  8. 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.
  9. 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.
  10. "* 94 Aqr". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2012-07-17.
  11. 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.
  12. 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.
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