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]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Chamaeleon |
| Right ascension | 11h 07m 46.091s[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 | |
| Database references | |
| SIMBAD | data |
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
edit- ^ a b c d 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.
- ^ a b "CHSM 10837". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 29 November 2016.
- ^ a b c d e f 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.
- ^ a b c 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.
- ^ 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
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