| Observation data Epoch J2000.0 | |
|---|---|
| Constellation | Centaurus |
| Right ascension | 12h 07m 33.4s |
| Declination | -39° 32' 54" |
| Apparent magnitude (V) | 13 |
| Distance | 173 ly (53 pc) |
| Spectral type | M8V |
| Other designations | |
2MASSW J1207334-393254
| |
2M1207, 2M1207A or 2MASSWJ 1207334-393254 is a brown dwarf star located at in the constellation Hydra; a companion object, 2M1207b, is believed to be one of the first extrasolar planets to be directly imaged, and is the first exoplanet to be discovered in orbit of a brown dwarf.
Located at right ascension 12hr 7min 33.4sec, and declination -39° 32′ 54″ (J2000.0 celestial coordinates), 2M1207 was discovered during the course of the 2MASS infrared sky survey: hence the "2M" in its name, followed by its celestial coordinates. It is roughly 53 parsecs away; with a fairly early (for a brown dwarf) spectral type of M8, it is very young, and a likely member of the TW Hydrae association. Its estimated mass is around 21 Jupiter masses.
In December 2005, American astronomer Eric Mamajek reported a more accurate distance to 2M1207 using the moving cluster method. The new distance (revised downwards from 70 parsecs) results in a fainter luminosity for 2M1207A, and its mass was revised downwards from an original value of 25 Jupiter masses.
2M1207b[]
- Main article: 2M1207b
| Extrasolar planet | Lists of extrasolar planets | |
|---|---|---|
| Observed position | ||
| Observed separation | (d) | 41 ± 5 AU |
| Physical characteristics | ||
| Mass | (m) | 3.3+1.5-1.0 MJ |
| Radius | (r) | 1.5 RJ |
| Density | (ρ) | ? kg/m3 |
| Temperature | (T) | 1250 ± 200 K |
| Discovery information | ||
| Discovery date | 2004 | |
| Discoverer(s) | Chauvin et al. | |
| Detection method | Imaged | |
| Discovery status | Confirmed | |
European Southern Observatory infrared image of 2M1207 (blueish) and companion planet 2M1207b (reddish), taken in 2004.
2M1207b is a planetary mass companion to 2M1207 detected in 2004 by imaging.
References[]
- Space.com - Astronomers Confident: Planet Beyond Solar System Has Been Photographed
- Space.com article on the discovery
- Extrasolar Planets Encyclopedia page on 2M1207 b
- "A Giant Planet Candidate Near a Young Brown Dwarf" (PDF) from the European Southern Observatory.
- "A Moving Cluster Distance to the Exoplanet 2M1207b in the TW Hydrae Association"