Astronomy:29 Aquarii

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Short description: Binary star in the constellation Aquarius
29 Aquarii
29AqrLightCurve.png
The light curve of 29 Aquarii, from Hipparcos data[1]
Observation data
Equinox J2000.0]] (ICRS)
Constellation Aquarius
Right ascension  22h 02m 26.24845s[2]
Declination −16° 57′ 53.3959″[2]
Apparent magnitude (V) 6.39[3]
Characteristics
Spectral type A2 V + K0 III[4]
B−V color index 0.447±0.022[3]
Astrometry
Radial velocity (Rv)+15.0±4.3[3] km/s
Proper motion (μ) RA: +5.292[2] mas/yr
Dec.: +1.256[2] mas/yr
Parallax (π)5.5489 ± 0.1285[5] mas
Distance590 ± 10 ly
(180 ± 4 pc)
Orbit[6]
Period (P)0.945 d
Eccentricity (e)0.00
Periastron epoch (T)2,436,814.418±1.0 JD
Semi-amplitude (K1)
(primary)
97.9 km/s
Other designations
BD−17°6422, HD 209278, HIP 108797, HR 8396, SAO 164830, WDS J22024-1658[7]
Database references
SIMBADdata

29 Aquarii is a binary star system located around 590 light years away from the Sun in the equatorial constellation of Aquarius. 29 Aquarii is the Flamsteed designation; the system also bears the variable star designation DX Aquarii. It is a challenge to view with the naked eye, appearing as a dim star with a combined apparent visual magnitude of 6.39.[3] The system is moving further from the Earth with a heliocentric radial velocity of about +15 km/s.[3]

This is a spectroscopic binary system with a close circular orbit taking just 0.945 days to complete.[6] Despite their proximity, this does not appear to be a contact binary system.[8] The orbital plane of the two stars lies near the line of sight, so they form an Algol-type eclipsing binary. The first component of the system is an A-type main sequence star with a stellar classification of A2 V. Its companion is giant star with a classification of K0 III.[4]

The variability of this system was first noticed in 1965 by W. Strohmeier of Remeis-Observatory in Bamberg, Germany .[9] He later discovered that the variability was caused by a binary companion eclipsing the primary star.[10]

References

  1. Molik, Petr. "Eclipsing binary DX Aqr". http://www.petrmolik.cz/shonpost.htm. 
  2. 2.0 2.1 2.2 2.3 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.
  3. 3.0 3.1 3.2 3.3 3.4 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode2012AstL...38..331A. 
  4. 4.0 4.1 Zasche, P. et al. (August 2009), "A Catalog of Visual Double and Multiple Stars With Eclipsing Components", The Astronomical Journal 138 (2): 664–679, doi:10.1088/0004-6256/138/2/664, Bibcode2009AJ....138..664Z. 
  5. 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. 
  6. 6.0 6.1 Paffhausen, W.; Seggewiss, W. (April 1976), "Spectroscopic orbits of the eclipsing binaries DV and CX Aqr", Astronomy and Astrophysics, Supplemental Series 24: 29–34, Bibcode1976A&AS...24...29P. 
  7. "BD-17 6422 -- Spectroscopic binary", SIMBAD Astronomical Object Database (Centre de Données astronomiques de Strasbourg), http://simbad.u-strasbg.fr/simbad/sim-id?Ident=BD-17+6422, retrieved 2012-07-16. 
  8. Rucinski, Slavek M. (October 2002), "The 7.5 Magnitude Limit Sample of Bright Short-Period Binary Stars. I. How Many Contact Binaries Are There?", The Publications of the Astronomical Society of the Pacific 114 (800): 1124–1142, doi:10.1086/342677, Bibcode2002PASP..114.1124R. 
  9. Strohmeier, W. et al. (1965). "Bright Southern BV-Stars". Information Bulletin on Variable Stars 81: 1. Bibcode1965IBVS...81....1S. https://konkoly.hu/pub/ibvs/0001/0081.txt. 
  10. Strohmeier, W. (1966). "BV 449 and BV 600, Two Bright EB-Stars". Information Bulletin on Variable Stars 164: 1. Bibcode1966IBVS..164....1S. http://www.konkoly.hu/cgi-bin/IBVS?0164. 

External links