CT Chamaeleontis

CT Chamaeleontis

Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Chamaeleon
Right ascension	11^h 04^m 09.131^s[1]
Declination	−76° 27′ 19.30″[1]
Apparent magnitude (V)	12.31 to 12.43[2]
Characteristics
Spectral type	K7[1]
B−V color index	−0.9[1]
V−R color index	0.8[1]
Variable type	INB[2]
Astrometry
Radial velocity (Rv)	15.1 ± 0.5[1] km/s
Proper motion (μ)	RA: −21.3 ± 4.6[3] mas/yr Dec.: 6.3 ± 4.5[3] mas/yr
Distance	540 ± 100 ly (165 ± 30[3] pc)
Details
Age	0 to 4 × 10^6 [3] years
Other designations
CT Cha.
Database references
SIMBAD	data

CT Chamaeleontis b

A size comparison between the colossal planet CT Chamaeleontis b and Jupiter.
Position (relative to CT Chamaleontis)
Epoch of observation	2006–2007
Angular distance	2.670″ [3]
Position angle	300.7° [3]
Observed separation (projected)	~440 AU [3]
Characteristics
Spectral type	M8–L0[3]
Details
Mass	0.016 ± 0.006[3] M☉
Radius	0.23+0.08 −0.06[3] R☉
Luminosity	0.002[3] L☉
Surface gravity (log g)	3.5[3] cgs
Temperature	2600 ± 250[3] K
Age	0 to 4 × 10^6 [3] years
Other designations
CT Cha b.
Database references
SIMBAD	data

CT Chamaeleontis (CT Cha) is a T Tauri star in the constellation of Chamaeleon.^[1] It has an apparent visual magnitude which varies between 12.31 and 12.43.^[2]

In 2006 and 2007, a faint companion was observed 2.7 arcseconds away from CT Chamaeleontis, using the Very Large Telescope at the European Southern Observatory. Since the object shares common proper motion with CT Chamaleontis, it is believed to be physically close to the star, with a projected separation of approximately 440 astronomical units. It is estimated to have a mass of approximately 17 Jupiter masses and is probably a brown dwarf.^[3] The companion has been designated CT Chamaeleontis b.^[4]

References

1. V* CT Cha -- T Tau-type Star, database entry, SIMBAD. Accessed on line October 1, 2008.
2. CT Cha, database entry, The combined table of GCVS Vols I-III and NL 67-78 with improved coordinates, General Catalogue of Variable Stars, Sternberg Astronomical Institute, Moscow, Russia. Accessed on line October 1, 2008.
3. Direct evidence of a sub-stellar companion around CT Cha, T. O. B. Schmidt et al., accepted for publication in Astronomy and Astrophysics, Bibcode: 2008arXiv0809.2812S, arXiv:0809.2812.
4. NAME CT Cha b -- Extra-solar Planet Candidate, database entry, SIMBAD. Accessed on line October 1, 2008.