Astronomy:94 Aquarii

From HandWiki
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. Bibcode2018A&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, Bibcode1978A&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. Bibcode2018A&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, Bibcode2008MNRAS.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. Bibcode2008MNRAS.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. Bibcode2013AJ....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. Bibcode2018AJ....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. Bibcode2020ApJ...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, Bibcode2006AJ....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, Bibcode1970CoAsi.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, Bibcode1962ApJ...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, Bibcode2007A&A...474..653V. 

External links