WASP-17 b is an exoplanet orbiting the star WASP-17 . This is the first discovered exoplanet that moves in a retrograde orbit , that is, it revolves around the star in the direction opposite to the rotation of the star itself [2] .
| Wasp-17b | |
|---|---|
| Exoplanet | |
 Comparative dimensions of WASP-17b (right) and Jupiter (left). | |
| Parent star | |
| Star | Wasp-17 |
| Constellation | Scorpio |
| Right Ascension ( α ) | 15 h 59 m 51 s |
| Declination ( δ ) | -28 ° 03 ′ 42 ″ |
| Visible magnitude ( m V ) | 11.6 |
| Distance | 1000 St. years old (300 pc ) |
| Spectral class | F6v |
| Elements of the orbit | |
| Semimajor axis ( a ) | 0.051 a. e. |
| Eccentricity ( e ) | 0.129 |
| Orbital Period ( P ) | 3.7354417 d. |
| Inclination ( i ) | 87.8 [1] ° |
| Pericenter Argument ( ω ) | −70 ° |
| Transit Time ( T t ) | 2454559.18102 [1] JD |
| physical characteristics | |
| Weight ( m ) | 0.49 M J |
| Radius ( r ) | 1.99 (± 0.08) [1] [2] R J |
| Gravity ( g ) | 3.074 m / s² (0.313 g ) |
| Discovery Information | |
| opening date | august 2009 |
| Discoverer (s) | David R. Anderson |
| Detection method | Transit method |
| Opening status | Posted by |
Content
Physical Characteristics
The diameter of WASP-17 b is larger than the diameter of any known exoplanet, and its mass is equal to half the mass of Jupiter , from which it can be assumed that the newly discovered planet has the lowest average density of all known exoplanets. The diameter of the planet is twice that of Jupiter. The average density is 0.1 g / cm³ (about 10% of the density of water ), which is 13 times less than the density of Jupiter and more than 6 times less than the density of Saturn , the least dense planet in the solar system.
In 2013, astronomers using the Hubble space telescope managed to find signs of water vapor in the planet’s atmosphere. [3]
Discovery History
The discovery of WASP-17 b was announced on August 11, 2009 [2] . A team of researchers led by David Anderson from Keele University discovered a gas giant rotating around the WASP-17 star using the telescopes of the South African Astronomical Observatory in transit. It got its name WASP-17 b, as it turned out to be the 17th open exoplanet in the framework of the British SuperWASP program [4] .
See also
- List of exoplanets discovered in 2009
- Loose planet
Notes
- ↑ 1 2 3 Planet: WASP-17 b . The Extrasolar Planet Encyclopedia . Date of treatment August 14, 2009. Archived on April 5, 2012.
- ↑ 1 2 3 DR Anderson et al. . WASP-17b: an ultra-low density planet in a probable retrograde orbit unspecified . Cornell University Library.
- ↑ Sensation! The Hubble telescope has found signs of life in the atmospheres of five exoplanets!
- ↑ Exoplanet moving in reverse orbit , NASA News in Russian (August 14, 2009). Archived on August 19, 2009.