Astronomy:WZ Andromedae

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Short description: Eclipsing binary star in the constellation Andromeda
WZ Andromedae
WZAndLightCurve.png
The visual band light curve of WZ Andromedae, adapted from Zhang & Zhang (2006)[1]
Observation data
Equinox J2000.0]] (ICRS)
Constellation Andromeda
Right ascension  01h 01m 43.64665s[2]
Declination +38° 05′ 46.48949″[2]
Apparent magnitude (V) 11.6 – 12.0 variable [3][4]
Characteristics
Spectral type F5 + G3 [4]
Apparent magnitude (B) 11.87[5]
Apparent magnitude (V) 11.26[5]
Apparent magnitude (G) 11.2631[2]
Apparent magnitude (J) 10.252[6]
Apparent magnitude (H) 9.930[6]
Apparent magnitude (K) 9.896[6]
B−V color index 0.5729[5]
Variable type EB
Astrometry
Proper motion (μ) RA: 14.260±0.072 [2] mas/yr
Dec.: −0.723±0.079[2] mas/yr
Parallax (π)1.8634 ± 0.0520[2] mas
Distance1,750 ± 50 ly
(540 ± 10 pc)
Orbit[4]
Period (P)0.6956612±0.0000001 yr
Periastron epoch (T)2446025.734±0.002
Details
Mass2.27[4][lower-alpha 1] M
Other designations
2MASS J01014364+3805464, TYC 2799-1250-1
Database references
SIMBADdata

WZ Andromedae (abbreviated to WZ And) is an eclipsing binary star in the constellation Andromeda. Its maximum apparent visual magnitude is 11.6,[4] but drops down to 12.00 during the main eclipse which occurs roughly every 16.7 hours.[3]

Variability

This binary star was found to be variable by Henrietta Leavitt, and shows the usual two eclipses, a main one and a secondary one with a less pronounced drop in magnitude. The period of 16.7 days, however, was found to vary in time without any consolidated trend.[4]

System

In an eclipsing binary system, the 16.7 day period is also the orbital period. The two stars are of spectral type F5 and G3, and they have almost the same mass. They could be so close that mass transfer is occurring in the system, changing the orbital period in time. An alternative explanation could be the presence in the system of two low mass companions with orbital periods of 50 and 70 years, respectively. Their contribution to the luminosity of the system, however, would be negligible (less than 1%), but they would have a large angular separation (45 and 72 mas) from the two main stars.[4]

Notes

  1. Total mass of the two main components

References

  1. Zhang, X.B.; Zhang, R.X. (March 2006). "WZ And, a probable contact system with mass ratio very close to unity". New Astronomy 11 (5): 339–343. doi:10.1016/j.newast.2005.08.009. Bibcode2006NewA...11..339Z. https://ui.adsabs.harvard.edu/abs/2006NewA...11..339Z/abstract. Retrieved 12 October 2021. 
  2. 2.0 2.1 2.2 2.3 2.4 2.5 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.
  3. 3.0 3.1 WZ And, database entry, Combined General Catalog of Variable Stars (GCVS4.2, 2004 Ed.), N. N. Samus, O. V. Durlevich, et al., CDS ID II/250 Accessed on line 2018-10-17.
  4. 4.0 4.1 4.2 4.3 4.4 4.5 4.6 Zasche, P.; Liakos, A.; Niarchos, P.; Wolf, M.; Manimanis, V.; Gazeas, K. (February 2009). "Period changes in six contact binaries: WZ And, V803 Aql, DF Hya, PY Lyr, FZ Ori, and AH Tau". New Astronomy 14 (2): 121–128. doi:10.1016/j.newast.2008.06.002. Bibcode2009NewA...14..121Z. 
  5. 5.0 5.1 5.2 Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P. et al. (2000), "The Tycho-2 catalogue of the 2.5 million brightest stars", Astronomy & Astrophysics 355: L27–L30, Bibcode2000A&A...355L..27H. 
  6. 6.0 6.1 6.2 Cutri, Roc M.; Skrutskie, Michael F.; Van Dyk, Schuyler D.; Beichman, Charles A.; Carpenter, John M.; Chester, Thomas; Cambresy, Laurent; Evans, Tracey E. et al. (2003). "VizieR Online Data Catalog: 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)". CDS/ADC Collection of Electronic Catalogues 2246: II/246. Bibcode2003yCat.2246....0C. http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=II/246.