2M1207
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Brown dwarf data from 2M1207 |
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| Infrared image (ESO / VLT) of the brown dwarf 2M1207 (image center) and its companion 2M1207 b (bottom left) (image: VLT / NACO, ESO, 2004) |
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| Observation dates equinox : J2000.0 , epoch : J2000.0 |
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| Constellation | centaur | ||
| Right ascension | 12 h 07 m 33 s | ||
| declination | −39 ° 32 ′ 54 ″ | ||
| Apparent brightness | about 20 mag | ||
| Known exoplanets | 1 | ||
| Radial velocity | (7.5 ± 2.0) km / s | ||
| parallax | (19.1 ± 0.4) mas | ||
| distance | (172 ± 3) ly (52.8 ± 1.0 pc ) |
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| Proper movement | |||
| Rec. Share: | (−63 ± 3) mas / a | ||
| Dec. portion: | (−23 ± 2) mas / a | ||
| Typing | |||
| Spectral class | M8 Ve | ||
| Physical Properties | |||
| Dimensions | approx. 60 M ♃ | ||
| Age | 8 million a | ||
| Other names and catalog entries |
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2M1207 is a young brown dwarf in the TW-Hydrae association in the constellation Water Snake , who is accompanied by an object with about 4 Jupiter masses. The companion with the systematic designation 2M1207 b is considered to be the first object of planetary mass from which a direct photo could be taken. To delimit his companion the brown dwarf is also known as 2M1207 A designated.
Main component
2M1207 was discovered in 2004 and initially referred to as "2MASSW J1207334-393254" according to the 2MASS rules. As a member of the TW-Hydrae Association, 2M1207 is also referred to as TWA 27 .
2M1207 is about 170 light years from Earth and has about 25 Jupiter masses . It belongs to the spectral class M8 and its age is estimated to be 8 million years .
The companion
2M1207 b was the first exoplanet that could be perceived directly optically (by direct imaging ) and thus offers the possibility of a direct spectroscopic investigation. The planet was discovered in 2004 with the brown dwarf 2M1207 , which resulted in its systematic name "2M1207 b".
The planet has about four times the mass of Jupiter and is therefore classified as a gas giant . At 214,000 km, the diameter of the planet is about 50% larger than that of Jupiter . The distance between companion and brown dwarf is about 40 AU .
| planet |
Mass ( M J ) |
Radius ( R J ) |
Orbital time ( d ) |
Semi-major axis ( AE ) |
eccentricity |
|---|---|---|---|---|---|
| 2M1207 b | 5 | 1.5 | ? | 42 +2−19 | ? |
literature
- Chauvin, G. et al .: Giant planet companion to 2MASSW J1207334-393254 , Astronomy and Astrophysics, Volume 438, Issue 2, August I 2005, pp.L25-L28 ( arxiv : astro-ph / 0504659 )
- Song, I. et al .: HST NICMOS Imaging of the Planetary-mass Companion to the Young Brown Dwarf 2MASS J1207334-393254 , Astrophysical Journal (Accepted), ( arxiv : astro-ph / 0607490 )
Web links
- Astronomers confirm first exoplanet image - article on astronews.com , May 2, 2005
- ESO Press Release 12/05 (English) - Press release of the ESO , from April 30, 2005
Individual evidence
- ↑ a b c d e f TWA 27. In: SIMBAD . Center de Données astronomiques de Strasbourg , accessed December 7, 2018 .
- ↑ a b c 2M1207 A. In: Extrasolar Planets Encyclopaedia . Retrieved December 7, 2018 .
- ↑ Ricci, L. et al .: ALMA Observations of the Young Substellar Binary System 2M1207 . In: The Astronomical Journal . 154, No. 1. arxiv : 1706.03708 . bibcode : 2017AJ .... 154 ... 24R . doi : 10.3847 / 1538-3881 / aa78a0 .
- ↑ A Giant Planet Candidate near a Young Brown Dwarf (English), September 14, 2004, arxiv : astro-ph / 0409323
- ↑ a b The Planetary Mass Companion 2MASS 1207-3932B: Temperature, Mass, and Evidence for an Edge-on Disk (English), March 2007, bibcode : 2007ApJ ... 657.1064M