Zeta Chamaeleontis

Zeta Chamaeleontis, Latinized from ζ Chamaeleontis, is a star located in the constellation Chamaeleon. Located around 540 light-years distant, it shines with a luminosity approximately 522 times that of the Sun and has a surface temperature of 15,655 K.

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.

It is a B5V main sequence star with an effective temperature of $−42.0$, 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.