HD 80606 b

HD 80606 b is an extrasolar planet, the yellow dwarf star HD 80606 orbits every 111.4277 days. Due to its mass is assumed that it is a gas planet.

Discovery

As the majority of exoplanets this one was also using the radial velocity method found. The discovery of the planet in 2001 was based on observations with the echelle spectrograph ELODIE at the 1.93 - m telescope of the Observatoire de Haute -Provence.

Circulation and mass

The star system HD 80606 is located at a distance of 190 light years (58 parsecs ) from Earth. The planet orbits its star at an average distance of about 0,468 astronomical units at an eccentricity of 0.93 and an orbital period of 111.4277 days. The observation of a short-term minimum in a Nahinfrarotlichtkurve of HD 80606 is interpreted as covering the planet by the star and enables the determination of the orbital inclination to i ≈ 90 °, that is, the Earth is quite accurate in the orbital plane of HD 80606 b. The planet has a mass of about 1370 Earth masses and 4.31 Jupiter masses. Its radius is estimated to 47,000 km.

Climate

Due to the high orbital eccentricity varies the distance of the planet from the star between 130 million miles Apastron and 5 million miles periastron. The average temperature is estimated at 700 K (430 ° C). During the Periastrondurchgangs the planet, however, receives a radiation flux, which is about 800 times as large as in Apastron and leads to a strong short-term heating of the planet. Observations in the near infrared spectral region with the Spitzer Space Telescope made ​​it in November 2007 to measure the temperature profile during a Periastrondurchganges directly. In this case, a rapid increase in temperature of about 800 K to 1500 K was observed within six hours. The atmosphere of HD 80606 b is responding much faster to changes in the radiation flux than would the Earth's atmosphere (the time scale for the stratosphere is about three to five days). According to atmospheric models performs the heating of the star- facing side of the planet to the formation of shock waves and extremely strong winds, whose top speeds are assumed to be up to 18,000 km / h.