University of Warwick | 2015 Nov 13
Winds of over 2km per second have been discovered flowing around planet outside of the Earth’s solar system, new research has found.
The planet HD 189733b is shown here in front of its parent star. A belt of wind around
the equator of the planet travels at 5,400 mph from the heated day side to the night
side. The day side of the planet appears blue due to scattering of light from silicate
haze in the atmosphere. The night side of the planet glows a deep red due to its high
temperature. (Credit: Mark A. Garlick/University of Warwick)
The University of Warwick discovery is the first time that a weather system on a planet outside of Earth’s solar system has been directly measured and mapped.
The wind speed recorded is 20x greater than the fastest ever known on earth, where it would be seven times the speed of sound.
Commenting on the discovery lead researcher Tom Louden, of the University of Warwick’s Astrophysics group, said: “This is the first ever weather map from outside of our solar system. Whilst we have previously known of wind on exoplanets, we have never before been able to directly measure and map a weather system.”
Discovered on the exoplanet HD 189733b, the Warwick researchers measured the velocities on the two sides of HD 189733b and found a strong wind moving at over 5400mph blowing from its dayside to its night side. Mr Louden explains: “HD 189733b’s velocity was measured using high resolution spectroscopy of the Sodium absorption featured in its atmosphere. As parts of HD 189733b’s atmosphere move towards or away from the Earth the Doppler effect changes the wavelength of this feature, which allows the velocity to be measured”. ...
Spatially resolved eastward winds and rotation of HD189733b - Tom Louden, Peter J. Wheatley
- arXiv.org > astro-ph > arXiv:1511.03689 > 11 Nov 2015
http://asterisk.apod.com/viewtopic.php?t=31711
http://asterisk.apod.com/viewtopic.php?t=31831