Astronomy:Zeta Chamaeleontis

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Short description: Variable star in the constellation Chamaeleon
ζ Chamaeleontis
Location of ζ Chamaeleontis (circled)
Observation data
Equinox J2000.0]] (ICRS)
Constellation Chamaeleon[1]
Right ascension  09h 33m 53.37537s[2]
Declination −80° 56′ 28.5287″[2]
Apparent magnitude (V) 5.07[1] (5.06 - 5.17)[3]
Characteristics
Evolutionary stage main sequence[2]
Spectral type B5V[1]
Variable type eclipsing[4]+ELL[5]
Astrometry
Radial velocity (Rv)−42.0±4.2 km/s
Proper motion (μ) RA: −34.582[2] mas/yr
Dec.: +13.564[2] mas/yr
Parallax (π)6.0043 ± 0.1134[2] mas
Distance540 ± 10 ly
(167 ± 3 pc)
Absolute magnitude (MV)−1.15[1]
Details
Mass3.12[6] M
Radius4.75[7] R
Luminosity522[8] L
Surface gravity (log g)3.55[6] cgs
Temperature15,655[9] K
Metallicity [Fe/H]−0.31[6] dex
Rotational velocity (v sin i)103[10] km/s
Age184[11] Myr
Other designations
CPD−80°365, HD 83979, HIP 46928, HR 3860, SAO 258538[12]
Database references
SIMBADdata

Zeta Chamaeleontis is a binary star system located in the constellation Chamaeleon. Its name is a Bayer designation that is Latinized from ζ Chamaeleontis, and abbreviated Zet Cha or ζ Cha. This is a 5th magnitude star, faintly visible to the naked eye under good observing conditions. Based on parallax measurements, it is located around 540 light-years distant.

Light curve for Zeta Chamaeleontis, plotted from TESS data[13]

South African Astronomer A.W.J. Cousins noted ζ Cha to vary between magnitudes 5.06 and 5.17 in 1960.[14] It was classified as a Beta Cephei variable in the Hipparcos and Tycho Catalogues (ESA 1997), with a period of 1.07 days,[15] before being reclassified as a slowly pulsating B star in the 2011 version.[16] It is now known to be an eclipsing binary star, with a period of 2.7 days,[4] with continuous variation through the whole cycle due to the ellipsoidal shape of the component stars.[5]

This is classified as a B5V main sequence, an absolute magnitude of −1.15 and a mass of 3.1 solar masses, although the properties are evaluated treating the system as a single star. It shines with a luminosity approximately 522 times that of the Sun and has a effective temperature of 15,655 K.

References

  1. 1.0 1.1 1.2 1.3 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode2012AstL...38..331A  XHIP record for this object at VizieR.
  2. 2.0 2.1 2.2 2.3 2.4 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940  Gaia DR3 record for this source at VizieR.
  3. Samus, N. N. et al. (2017). "General Catalogue of Variable Stars". Astronomy Reports. 5.1 61 (1): 80–88. doi:10.1134/S1063772917010085. Bibcode2017ARep...61...80S. 
  4. 4.0 4.1 IJspeert, L. W. et al. (August 2021). "An all-sky sample of intermediate- to high-mass OBA-type eclipsing binaries observed by TESS". Astronomy & Astrophysics 652: A120. doi:10.1051/0004-6361/202141489. Bibcode2021A&A...652A.120I. 
  5. 5.0 5.1 "Zeta Cha". AAVSO. https://www.aavso.org/vsx/index.php?view=detail.top&oid=9399. 
  6. 6.0 6.1 6.2 Anders, F. et al. (2019). "Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia DR2 stars brighter than G = 18". Astronomy and Astrophysics 628: A94. doi:10.1051/0004-6361/201935765. Bibcode2019A&A...628A..94A. 
  7. Kervella, Pierre et al. (2022). "Stellar and substellar companions from Gaia EDR3". Astronomy & Astrophysics 657: A7. doi:10.1051/0004-6361/202142146. Bibcode2022A&A...657A...7K. 
  8. McDonald, I. et al. (2012). "Fundamental Parameters and Infrared Excesses of Hipparcos Stars". Monthly Notices of the Royal Astronomical Society 427 (1): 343–57. doi:10.1111/j.1365-2966.2012.21873.x. Bibcode2012MNRAS.427..343M. 
  9. Cardiel, Nicolás et al. (2021). "Synthetic RGB photometry of bright stars: Definition of the standard photometric system and UCM library of spectrophotometric spectra". Monthly Notices of the Royal Astronomical Society 504 (3): 3730. doi:10.1093/mnras/stab997. Bibcode2021MNRAS.504.3730C. 
  10. Glebocki, R.; Gnacinski, P. (2005). "VizieR Online Data Catalog: Catalog of Stellar Rotational Velocities (Glebocki+ 2005)". VizieR On-line Data Catalog: III/244. Originally Published in: 2005csss...13..571G; 2005yCat.3244....0G 3244. Bibcode2005yCat.3244....0G. 
  11. Gontcharov, G. A. (December 2012). "Dependence of kinematics on the age of stars in the solar neighborhood". Astronomy Letters 38 (12): 771–782. doi:10.1134/S1063773712120031. ISSN 0320-0108. Bibcode2012AstL...38..771G. 
  12. "zet Cha". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=zet+Cha. 
  13. "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. https://mast.stsci.edu/portal/Mashup/Clients/Mast/Portal.html. 
  14. Cousins, A.W.J. (1960). "New Bright Variable Stars". Monthly Notes of the Astronomical Society of Southern Africa 19: 56. Bibcode1960MNSSA..19...56C. 
  15. ESA (1997). The HIPPARCOS and TYCHO catalogues. Astrometric and photometric star catalogues derived from the ESA HIPPARCOS Space Astrometry Mission. 1200. ISBN 9290923997. Bibcode1997ESASP1200.....E. 
  16. Dubath, P. et al. (2011). "Random forest automated supervised classification of Hipparcos periodic variable stars". Monthly Notices of the Royal Astronomical Society 414 (3): 2602–17. doi:10.1111/j.1365-2966.2011.18575.x. Bibcode2011MNRAS.414.2602D.