Zeta Chamaeleontis

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

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

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 an effective temperature of 15,655 K.

References

  1. 1 2 3 4 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. XHIP record for this object at VizieR.
  2. 1 2 3 4 5 6 Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. 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. Bibcode:2017ARep...61...80S. doi:10.1134/S1063772917010085. S2CID 125853869.
  4. 1 2 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. arXiv:2107.10005. Bibcode:2021A&A...652A.120I. doi:10.1051/0004-6361/202141489.
  5. 1 2 "Zeta Cha". International Variable Star Index. AAVSO. Retrieved 2023-07-27.
  6. 1 2 3 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. arXiv:1904.11302. Bibcode:2019A&A...628A..94A. doi:10.1051/0004-6361/201935765. S2CID 131780028.
  7. ↑ Kervella, Pierre; et al. (2022). "Stellar and substellar companions from Gaia EDR3". Astronomy & Astrophysics. 657: A7. arXiv:2109.10912. Bibcode:2022A&A...657A...7K. doi:10.1051/0004-6361/202142146. S2CID 237605138.
  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. arXiv:1208.2037. Bibcode:2012MNRAS.427..343M. doi:10.1111/j.1365-2966.2012.21873.x. S2CID 118665352.
  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. arXiv:2103.17009. Bibcode:2021MNRAS.504.3730C. doi:10.1093/mnras/stab997.
  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. Bibcode:2005yCat.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. arXiv:1606.08814. Bibcode:2012AstL...38..771G. doi:10.1134/S1063773712120031. ISSN 0320-0108. S2CID 255201789.
  12. ↑ "zet Cha". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2026-03-31.
  13. ↑ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 25 September 2022.
  14. ↑ Cousins, A.W.J. (1960). "New Bright Variable Stars". Monthly Notes of the Astronomical Society of Southern Africa. 19: 56. Bibcode:1960MNSSA..19...56C.
  15. ↑ ESA (1997). The HIPPARCOS and TYCHO catalogues. Astrometric and photometric star catalogues derived from the ESA HIPPARCOS Space Astrometry Mission. Vol. 1200. Bibcode:1997ESASP1200.....E. ISBN 9290923997.
  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. arXiv:1101.2406. Bibcode:2011MNRAS.414.2602D. doi:10.1111/j.1365-2966.2011.18575.x. S2CID 118560311.