Zeta Chamaeleontis
Variable star in the constellation Chamaeleon
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Zeta Chamaeleontis, Latinized from ζ Chamaeleontis, is a star located in the constellation Chamaeleon. It is a 5th magnitude star, faintly visible to the naked eye under good observing conditions. 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.
 | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Chamaeleon |
| Right ascension | 09h 33m 53.37537s[1] |
| Declination | −80° 56′ 28.5287″[1] |
| Apparent magnitude (V) | 5.07[2] (5.06 - 5.17)[3] |
| Characteristics | |
| Evolutionary stage | main sequence[1] |
| Spectral type | B5V[2] |
| Variable type | eclipsing[4]+ELL[5] |
| Astrometry | |
| Radial velocity (Rv) | −42.0±4.2 km/s |
| Proper motion (μ) | RA: −34.582[1] mas/yr Dec.: +13.564[1] mas/yr |
| Parallax (π) | 6.0043±0.1134 mas[1] |
| Distance | 540 ± 10 ly (167 ± 3 pc) |
| Absolute magnitude (MV) | −1.15[2] |
| Details | |
| Mass | 3.12[6] M☉ |
| Radius | 4.75[7] R☉ |
| Luminosity | 522[8] L☉ |
| Surface gravity (log g) | 3.55[6] cgs |
| Temperature | 15,655[9] K |
| Metallicity [Fe/H] | −0.31[6] dex |
| Rotational velocity (v sin i) | 103[10] km/s |
| Age | 184[11] Myr |
| Other designations | |
| CPD−80°365, HD 83979, HIP 46928, HR 3860, SAO 258538 | |
| Database references | |
| SIMBAD | data |
South African Astronomer A.W.J. Cousins noted ζ Cha to vary between magnitudes 5.06 and 5.17 in 1960.[13] It was classified as a Beta Cephei variable in the Hipparcos and Tycho Catalogues (ESA 1997), with a period of 1.07 days,[14] before being reclassified as a slowly pulsating B star in the 2011 version.[15] 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]
It is a B5V main sequence star with an effective temperature of 15,655 K, 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.