ChaHα8

ChaHα8

ChaHα8 with the Spitzer Space Telescope
Observation data Epoch J2000      Equinox J2000
Constellation	Chamaeleon
Right ascension	11^h 07^m 46.091^s[1]
Declination	−77° 40′ 08.92″[1]
Apparent magnitude (V)	20.1[2]
Characteristics
Spectral type	M5.75–M6.5[3]
Astrometry
Proper motion (μ)	RA: -23.455 mas/yr[1] Dec.: 0.453 mas/yr[1]
Parallax (π)	5.0899 ± 0.0792 mas[1]
Distance	641 ± 10 ly (196 ± 3 pc)
Orbit[4]
Period (P)	1895±132 d
Semi-major axis (a)	1.02±0.06–1.17±0.07 AU
Eccentricity (e)	0.59±0.22
Periastron epoch (T)	2453163±214 JD
Argument of periastron (ω) (secondary)	106±26°
Semi-amplitude (K1) (primary)	2.433±0.44 km/s
Details
ChaHα8 A
Mass	0.07–0.10[3] M☉
Temperature	2910–3024[3] K
Rotational velocity (v sin i)	15.5±2.6[3] km/s
Age	~3[3] Myr
ChaHα8 B
Mass	25±7–31±8[4] MJup
Other designations
2MASS J11074610-7740089, CHSM 10837, SBC9 3352, Cha Hα 8[2]
Database references
SIMBAD	data

ChaHα8 (also written ChaHa8 when Greek letters are unavailable) is a binary brown dwarf about 640 light-years (200 parsecs) from Earth in the constellation Chamaeleon. The designation indicates that it is in the Chamaeleon I star-forming region and that it displays hydrogen-alpha emission. It was discovered in 2000.^[5]

It was found in 2007 to have a low-mass substellar companion in orbit around it via radial velocity observations.^[3] The companion has a mass of 25–31 Jupiter masses, and the pair orbit each other with a period of 5.2 years and an eccentricity of 0.59.^[4]

References

1. Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
2. "CHSM 10837". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 29 November 2016.
3. Joergens, V.; A. Mueller (2007). "16–20 Jupiter mass RV companion orbiting the brown dwarf candidate ChaHa8". The Astrophysical Journal. 666 (2). arXiv:0707.3744. Bibcode:2007ApJ...666L.113J. doi:10.1086/521825. S2CID 119140521.
4. Joergens, V.; Müller, A.; Reffert, S. (2010). "Improved radial velocity orbit of the young binary brown dwarf candidate Cha Hα 8". Astronomy and Astrophysics. 521 (A24): A24. arXiv:1006.2383. Bibcode:2010A&A...521A..24J. doi:10.1051/0004-6361/201014853. S2CID 54989533.
5. Comerón, F.; Neuhäuser, R.; Kaas, A. A. (2000). "Probing the brown dwarf population of the Chamaeleon I star forming region". Astronomy and Astrophysics. 359: 269–288. Bibcode:2000A&A...359..269C.

External links

• Video of the radial velocity orbit of the brown dwarf binary ChaHα8