Z Chamaeleontis

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Z Chamaeleontis
Observation data
Epoch J2000      Equinox J2000
Constellation Chamaeleon
Right ascension 08h 07m 27.75s
Declination −76° 32′ 00.7″
Apparent magnitude (V) +13.0
Spectral type DA / M6V
Distance 316.2 ly
(97 pc)
Mass 0.7/0.12 M
Radius 0.013/0.48 R
Luminosity 0.007/0.017 L
Temperature 14,700/3100 K
Period (P) 0.0002 yr
Semi-major axis (a) 0.003 AU
Inclination (i) 81.7°
Other designations
Z Cha, 2E 1942, SBC9 505, CSV 1244, 2MASS J08072774-7632006, SON 4893, 2E 0808.8-7622, 1RXS J080728.8-763157, AAVSO 0809-76
Database references

Z Chamaeleontis (abbreviated Z Cha) is a dwarf nova variable star system approximately 316 light-years away from the Sun, where two stars orbit each other every 1.78 hours. The system comprises an eclipsing white dwarf and red dwarf and possibly a yet unconfirmed third low-mass substellar companion.[1]

Substellar companion[edit]

Dai et al. (2009) invoke the presence of a third object to explain orbital period variations with an apparent periodicity of roughly 28 years. The third body could yield a minimum mass 20 times greater than Jupiter and be located 9.9 Astronomical Units away from the dwarf nova, being likely a low-mass brown dwarf.

The Z Chamaeleontis planetary system[1]
(in order from star)
Mass Semimajor axis
Orbital period
Eccentricity Inclination Radius
b (unconfirmed) ≥20 MJ 9.9 28 ≤0.2

See also[edit]


  1. ^ a b Dai; Qian, Shengbang; Lajús, Eduardo FernáNdez (2009). "Evidence of a Brown Dwarf in the Eclipsing Dwarf Nova Z Chamaeleonis". The Astrophysical Journal. 703 (1): 109–113. Bibcode:2009ApJ...703..109D. doi:10.1088/0004-637X/703/1/109. 

Coordinates: Sky map 08h 07m 27.75s, −76° 32′ 00.7″