HD 189733
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| Observation data Epoch J2000.0 |
|
|---|---|
| Constellation (pronunciation) |
Vulpecula |
| Right ascension | 20h 00m 43.7133s |
| Declination | +22° 42′ 39.070″ |
| Apparent magnitude (V) | 7.67 |
| Distance | 62.9 ly (19.3 pc) |
| Spectral type | K1-K2 (Hip. lists G5) |
| Other designations | |
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GJ 4130, HIP 98505
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HD 189733 (HD 189733 A) is a yellow dwarf star about 63 light-years away in the constellation Vulpecula, and host to at least one extrasolar planet. It is a member of a binary star system. Given that this star has the same visual magnitude as HD 209458, it promises much for the study of close transiting extrasolar planets. The star can be found with binoculars 0.3 degrees east of the Dumbbell Nebula (M27).
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[edit] Planetary system
HD 189733 has one known planet, designated HD 189733 b, a gaseous giant 15% larger than Jupiter close enough to complete an orbit every two days. Using spectrometry it was found in 2007 that this planet contains significant amounts of water vapour. This planet is the second extrasolar planet where definitive evidence for water has been found.[1]
The chemical signature of water vapour was detected in the atmosphere of this planet. Although HD 189733b with atmospheric temperatures rising above 1 000 °C is far from being habitable, this finding increases the likelihood that water, an essential component of life, would be found on a more Earth-like planet in the future. [2]
[edit] HD 189733 B
| Observation data Epoch J2000.0 |
|
|---|---|
| Constellation (pronunciation) |
Vulpecula |
| Right ascension | 20h 00m 43.7133s |
| Declination | +22° 42′ 39.070″ |
| Apparent magnitude (V) | unknown |
| Distance | 62.9 ly (19.3 pc) |
| Spectral type | M? |
| Other designations | |
|
2MASS J20004297+2242342
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HD 189733 B is a stellar companion of HD 189733 A. At about 216 AU from its primary, this M-dwarf orbits star A every 3,200 years.
[edit] References
- ^ Water vapour found on exoplanet. Retrieved on 2007-07-12.
- ^ 'Clear Signs of Water' on Distant Planet (2007-07-11). Retrieved on 2008-02-02.
