Gliese 436 b
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Exoplanet Gliese 436 b |
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| Artist's impression of Gliese 436b and its star | |
| Constellation | lion |
| Position equinox : J2000.0 |
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| Right ascension | 11h 42m 11.1s |
| declination | + 26 ° 42 ′ 24 ″ |
| Orbit data | |
| Central star | Peter 436 |
| Major semi-axis | 0.029 ± 0.001 AU |
| eccentricity | 0.19 ± 0.05 |
| Further data | |
| diameter | approx. 54,000 km |
| Dimensions | (0.070 ± 0.005) M J (22.2 ± 1.0) M ⊕ |
| distance | (9.76 ± 0.01) pc |
| Orbital time | 2.64 days |
| history | |
| discovery | Geoffrey Marcy and R. Paul Butler |
| Date of discovery | 2004 |
| Catalog names | |
| Gliese 436 b | |
| More information | |
| Hot Neptune | |
Gliese 436 b (also GJ 436 b ) is an exoplanet orbiting the red dwarf Gliese 436 . He is an ice giant and possibly a so-called " Hot Neptune ". Gliese 436 b was discovered by Geoffrey Marcy and R. Paul Butler in 2004 by measuring the star's radial velocity.
properties
Gliese 436 b orbits its central star at a distance of only 0.03 AU (around 4.3 million km) every 2 days, 15 hours and 27 minutes on an orbit with an eccentricity of 0.15, its mass is around 0.072 Jupiter's masses . As part of the work with the Spitzer Space Telescope , the diameter of the exoplanet could be determined relatively accurately to 54,000 km (slightly more than that of the planet Neptune ) using the transit method . In connection with common planetary models, these data suggest a structure similar to that of Neptune.
Because the planet gets so hot, part of its atmosphere escapes into space and forms a comet-tail-like cloud. About two hours before Gliese 436 b moves in front of its central star, the ultraviolet light begins to darken. During the passage, the brightness of the red dwarf is only 44% and then gradually increases again. In visible light, however, the decrease in brightness is only 0.7%. During this process, around 100 to 1000 tons of hydrogen escape per second .
Web links
- The exoplanet in the "Encyclopedia of Extrasolar Planets"
- GJ 436 b at exoplanets.org
Individual evidence
- ^ A b Ross 905. In: SIMBAD . Center de Données astronomiques de Strasbourg , accessed on November 17, 2019 .
- ↑ a b c d GJ 436 b. In: Extrasolar Planets Encyclopaedia . Retrieved November 17, 2019 .
- ↑ a b Guillermo Torres: The Transiting Exoplanet Host Star GJ 436: A Test of Stellar Evolution Models in the Lower Main Sequence, and Revised Planetary Parameters (PDF; 85 kB). In: The Astrophysical Journal , Vol. 671, No. 1, pp. L65-L68 (2007)
- ↑ a b Deming et al .: Spitzer Transit and Secondary Eclipse Photometry of GJ 436b . In: The Astrophysical Journal , Vol. 667, No. 2, pp. L199 – L202 (2007)
- ↑ Hot "ice" may cover recently discovered planet . In: Reuters . 2007 ( reuters.com ).
- ↑ Tilmann Althaus: The exoplanet GJ 436b is surrounded by a huge gas tail made of hydrogen. The exoplanet GJ 436b appears like a comet in the ultraviolet, which has a huge gas tail made of hydrogen. During its orbits, it covers the central star for several hours. Retrieved June 26, 2015 .