HD 189733 b
| Exoplanet | List of exoplanets | |
|---|---|---|
 |
||
| Parent star | ||
| Star | HD 189733 A | |
| Constellation | Vulpecula | |
| Right ascension | (α) | 20h 00m 43.71s |
| Declination | (δ) | +22° 42′ 39.1″ |
| Apparent magnitude | (mV) | 7.66 |
| Distance | 63.4 ± 0.9 ly (19.5 ± 0.3 pc) |
|
| Spectral type | K1–2V | |
| Mass | (m) |
0.846+0.068 −0.049 M☉ |
| Radius | (r) | 0.805±0.016 R☉ |
| Temperature | (T) | 4875±43 K |
| Metallicity | [Fe/H] | −0.03 ± 0.04 |
| Age | 4.3±2.8 Gyr | |
| Orbital elements | ||
| Semi-major axis | (a) | 0.03099 ± 0.0006 AU (4.636 ± 0.09 Gm) |
| Periastron | (q) | 0.03096 AU (4.632 Gm) |
| Apastron | (Q) | 0.03102 AU (4.641 Gm) |
| Eccentricity | (e) | 0.0010 ± 0.0002 |
| Orbital period | (P) | 2.2185733 ± 0.00002 d |
| (53.245759 h) | ||
| Orbital speed | (υ) | 152.5 km/s |
| Inclination | (i) | 85.76 ± 0.29° |
| Time of transit | (Tt) | 2,453,988.80336 ± 0.00024 JD |
| Semi-amplitude | (K) | 205 ± 6 m/s |
| Physical characteristics | ||
| Mass | (m) |
1.162+0.058 −0.039MJ |
| Radius | (r) | 1.138 ± 0.027 RJ |
| Stellar flux | (F⊙) | 275 ⊕ |
| Geometric Albedo | (Ag) | 0.40 ± 0.12 (290–450 nm) < 0.12 (450–570 nm) |
| Surface gravity | (g) | 21.2 m/s² |
| Temperature | (T) | 1117 ± 42 K |
| Discovery information | ||
| Discovery date | 5 October 2005 | |
| Discoverer(s) | Bouchy et al. | |
| Discovery method |
Doppler spectroscopy Transit |
|
| Other detection methods | Polarimetry Reflection/emission modulations |
|
| Discovery site | Haute-Provence Observatory | |
| Discovery status | Confirmed | |
| Database references | ||
| Extrasolar Planets Encyclopaedia |
data | |
| SIMBAD | data | |
| Exoplanet Archive | data | |
| Open Exoplanet Catalogue | data | |
HD 189733 b is an extrasolar planet approximately 63 light-years away from the Solar System in the constellation of Vulpecula. The planet was discovered orbiting the star HD 189733 A on October 5, 2005, when astronomers in France observed the planet transiting across the face of the star. With a mass 13% higher than that of Jupiter, HD 189733 b orbits its host star once every 2.2 days at an orbital speed of 152.5 kilometres per second (341,000 mph), making it a hot Jupiter with poor prospects for extraterrestrial life. Being the closest transiting hot Jupiter to Earth, HD 189733 b is a subject for extensive atmospheric examination. HD 189733 b was the first extrasolar planet for which a thermal map was constructed, to be detected through polarimetry, to have its overall color determined (deep blue), to have a transit detected in X-ray spectrum and to have carbon dioxide detected in its atmosphere.
In July, 2014, NASA announced finding very dry atmospheres on three exoplanets (HD 189733b, HD 209458b, WASP-12b) orbiting Sun-like stars.
On October 6, 2005, a team of astronomers announced the discovery of transiting planet HD 189733 b. The planet was then detected using Doppler spectroscopy. Real-time radial velocity measurements detected the Rossiter–McLaughlin effect caused by the planet passing in front of its star before photometric measurements confirmed that the planet was transiting. In 2006, a team led by Drake Deming announced a detection of strong infrared thermal emission from the transiting extrasolar planet HD 189733 b, by measuring the flux decrement (decrease of total light) during its prominent secondary eclipse (when the planet passes behind the star).
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