HD 189733 b
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Exoplanet HD 189733 b |
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| A rendering of HD 189733b after the first confirmation of the color of an exoplanet with the Hubble Space Telescope | |
| Constellation | Fox |
| Position equinox : J2000.0 |
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| Right ascension | 20h 00m 43.713s |
| declination | + 22 ° 42 ′ 39.072 ″ |
| Orbit data | |
| Central star | HD 189733 |
| Major semi-axis | 0.031 AU |
| eccentricity | 0.004 ± 0.002 |
| Period of circulation | 2.219 d |
| Further data | |
| radius | 1.138 ± 0.077 R J |
| Dimensions | 1.142 ± 0.025 M J |
| distance | 19.78 pc |
| Discovery method | Transit method |
| Orbit inclination | 85.51 ± 0.05 ° |
| history | |
| discovery | Bouchy et al. |
| Date of discovery | October 11, 2005 |
| Catalog names | |
| HD 189733 b | |
HD 189733 b is the name of the first exoplanet on which methane gas was detected. It orbits the main sequence star HD 189733 , which is about 64 light years away from our solar system. The planet has neither a moon with a radius of more than 0.8 earth radii nor a ring system like Saturn .
On October 11, 2005, the giant planet was discovered at HD 189733 in the constellation Vulpecula with the help of the astrometry satellite Hipparcos . In addition, the planet was examined on February 21, 2006 by the Spitzer infrared telescope . It is particularly suitable for investigations into the composition of the atmosphere because it crosses the solar disk of its home star when viewed from Earth. As one of the transit planets closest to the sun , it is therefore particularly easy to study.
HD 189733 b orbits its star at a distance of 0.0312 (± 0.0004) AU and orbits its parent star once in just 2 days. The surface temperature of the planet is over 1000 degrees Celsius.
On December 9, 2008, NASA announced that water vapor, carbon dioxide and carbon monoxide could also be detected. This is considered an important step on the way to the detection of further chemical compounds that are possibly influenced or have been influenced by living things, as reported by NASA.
In March 2010, transit observations were carried out that showed that atomic hydrogen escapes from the exosphere of the planet in the range of 1 to 100 kilotons per second into space. HD 189733 b is the second extrasolar planet after HD 209458 b , where this atmospheric phenomenon was discovered.
On July 11, 2013, NASA reported that observations with the Hubble Space Telescope had determined the actual color of an exoplanet for the first time. HD 189733 b is therefore colored deep blue and therefore appears quite earth-like in color to a human observer. However, this color is presumably caused by light reflections from tiny glass particles that, driven by strong winds, fly through the atmosphere at speeds of up to 7000 km / h.
Web links
- Hubble Finds Carbon Dioxide on an Extrasolar Planet
- The exoplanet in the "Encyclopedia of Extrasolar Planets"
Individual evidence
- ↑ HD 189733b. In: SIMBAD . Center de Données astronomiques de Strasbourg , accessed on January 13, 2019 .
- ↑ a b c d e f g HD 189733 b. In: Extrasolar Planets Encyclopaedia . Retrieved January 13, 2019 .
- ↑ HD 189733. In: SIMBAD. Center de Données astronomiques de Strasbourg, accessed on January 13, 2019 .
- ↑ Frédéric Pont et al .: Hubble Space Telescope time-series photometry of the planetary transit of HD189733: no moon, no rings, starspots . In: Astronomy and Astrophysics . 476, No. 3, 2008, pp. 1347-1355.
- ↑ ESA press release: Artist's impression of the deep blue planet HD 189733b
- ↑ Lecavelier des Etangs et al .: Evaporation of the planet HD189733b observed in HI Lyman-alpha . In: Astronomy & Astrophysics . 1003, 2010, p. 2206.
- ↑ Stefan Deiters: HD 189733b is a deep blue world. astronews.com, July 11, 2013, accessed January 19, 2014 .