HD 80606 b

The variable radial velocity of HD 80606 was first noticed in 1999 from observations with the 10-m Keck 1 telescope at the W. M. Keck Observatory in Hawaii by the G-Dwarf Planet Search, a survey of nearly 1000 nearby G dwarfs to identify extrasolar planet candidates. The star was then followed up by the Geneva Extrasolar Planet Search team using the ELODIE spectrograph mounted on the 1.93-m telescope at the Haute-Provence Observatory. The discovery of HD 80606 b was announced on 4 April 2001. == Physical properties ==

HD 80606 b has the most eccentric orbit of any known planet after HD 20782 b. Its eccentricity is 0.9336, comparable to Halley's Comet. The eccentricity may be a result of the Kozai mechanism, which would occur if the planet's orbit is significantly inclined to that of the binary stars. This interpretation is supported by measurements of the Rossiter–McLaughlin effect, which indicate that the planet's orbit may be significantly inclined (by 42°) to the rotational axis of the star, a configuration which would be expected if the Kozai mechanism were responsible for the orbit. As a result of this high eccentricity, the planet's distance from its star varies from 0.03 to 0.88 AU. At apastron it would receive an insolation similar to that of Earth, while at periastron the insolation would be around 800 times greater, far more than that experienced by Mercury in the Solar System. In 2009, the eclipse of HD 80606 b by its parent star was detected, allowing measurements of the planet's temperature to be made as the planet passed through periastron. These measurements indicated that the temperature rose from around to in just 6 hours. An observer above the cloud tops of the gas giant would see the parent star swell to 30 times the apparent size of the Sun in our own sky. The planet's rotation period has been measured to be hours, longer than the predicted pseudo-synchronous rotation period of 40 hours. == Weather ==

The planet has wild variations in its weather as it orbits its parent star. Computer models predict the planet heats up in just a matter of hours, triggering "shock wave storms" that ripple out from the point facing its star, with winds that move at around . == References ==