Z Chamaeleontis - Misplaced Pages

Variable star in the constellation ChamaeleonNot to be confused with Zeta Chamaeleontis.

Z Chamaeleontis
Observation data Epoch J2000 Equinox J2000
A light curve for Z Chamaeleontis, adapted from Wood et al. (1986)
Constellation	Chamaeleon
Right ascension	08 07 27.7517
Declination	−76° 32′ 00.6650″
Apparent magnitude (V)	11.5 - 16.2
Characteristics
Spectral type	DA? + M5.5e
Variable type	SU UMa + Algol
Astrometry

Radial velocity (R_v)	−20 km/s
Proper motion (μ)	RA: −33.650 mas/yr Dec.: +56.883 mas/yr
Parallax (π)	8.2805 ± 0.074 mas
Distance	394 ± 4 ly (121 ± 1 pc)

Orbit
Primary	white dwarf
Companion	red dwarf
Period (P)	1.79 d
Eccentricity (e)	0
Inclination (i)	81.8±0.1°
Semi-amplitude (K₁) (primary)	105 km/s
Details
white dwarf
Mass	1 `M`_☉
Radius	0.013/0.48 `R`_☉
Luminosity	0.007/0.017 `L`_☉
Temperature	14,700/3100 K
red dwarf
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
SIMBAD	data

Z Chamaeleontis (abbreviated Z Cha) is a dwarf nova variable star system approximately 394 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.

Substellar companion

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
Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (years)	Eccentricity	Inclination	Radius
b (unconfirmed)	≥20 M_J	9.9	28	≤0.2	—	—

References

Wood, Janet; Horne, Keith; Berriman, Graham; Wade, R.; O'Donoghue, D.; Warner, B. (April 1986). "High-speed photometry of the dwarf nova Z Cha in quiescence". Monthly Notices of the Royal Astronomical Society. 219 (3): 629–655. Bibcode:1986MNRAS.219..629W. doi:10.1093/mnras/219.3.629.
Watson, C. L.; Henden, A. A.; Price, A. (May 2006). "The International Variable Star Index (VSX)". Society for Astronomical Sciences Annual Symposium. 25: 47. Bibcode:2006SASS...25...47W.
Wade, Richard A.; Horne, Keith (January 1988). "The radial velocity curve and peculiar TiO distribution of the red secondary star in Z Chamaeleontis". The Astrophysical Journal. 324: 411. Bibcode:1988ApJ...324..411W. doi:10.1086/165905. eISSN 1538-4357. ISSN 0004-637X.
Samus’, N. N.; Kazarovets, E. V.; Durlevich, O. V.; Kireeva, N. N.; Pastukhova, E. N. (January 2017). "General catalogue of variable stars: Version GCVS 5.1". Astronomy Reports. 61 (1): 80–88. Bibcode:2017ARep...61...80S. doi:10.1134/S1063772917010085. ISSN 1063-7729. S2CID 255195566.
Duflot, M.; Figon, P.; Meyssonnier, N. (December 1995). "Vitesses radiales. Catalogue WEB: Wilson Evans Batten. Subtittle: Radial velocities: The Wilson-Evans-Batten catalogue". Astronomy and Astrophysics Supplement Series. 114: 269. Bibcode:1995A&AS..114..269D. ISSN 0365-0138.
^ Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
^ Marsh, T. R.; Horne, Keith; Shipman, H. L. (April 1987). "A spectrophotometric study of the emission lines in the quiescent dwarf nova Z Chamaeleontis". Monthly Notices of the Royal Astronomical Society. 225 (3): 551–580. Bibcode:1988ApJ...324..411W. doi:10.1093/mnras/225.3.551. eISSN 1365-2966. ISSN 0035-8711.
^ Otulakowska-Hypka, Magdalena; Olech, Arkadiusz; Patterson, Joseph (12 May 2016). "Statistical analysis of properties of dwarf novae outbursts". Monthly Notices of the Royal Astronomical Society. 460 (3): 2526–2541. arXiv:1605.02937. Bibcode:2016MNRAS.460.2526O. doi:10.1093/mnras/stw1120. eISSN 1365-2966. ISSN 0035-8711.
^ Dai; Qian, Shengbang; Lajús, Eduardo FernáNdez (26 August 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.

Constellation of Chamaeleon

Stars

Bayer	α β γ δ δ ε ζ η θ ι κ μ μ ν π
Variable	R T Z RS RZ CT CU DI DR DX DY
HR	3393 3543 3695 4170 4268 4385 4397 4507 4509 4649 4976 5188
HD	63454 (Ceibo) 115088 116852
Other	2MASS J11011926–7732383 AB ChaHα8 CHXR 73 L 34-26 WISEA J120037.79-784508.3

Exoplanets	Cha 110913−773444 ChaHα8 b COCONUTS-2b HD 63454 b OTS 44

Star clusters	η Chamaeleontis cluster

Nebulae	Chamaeleon complex NGC 3195 IC 2631

Galaxies

NGC	2915

Substellar companion

See also

References