Exoplanet HD 189733b Is Super Windy

The planet  HD 189733b is windy, really windy.

The planet, located about 63 light years away in the constellation Vulpecula, has winds reaching 5,400 mph, roughly 20 times faster than anything ever experienced on Earth, reports Discovery News.

Granted, everything about HD 189733b is extreme.

HD 189733 b was discovered orbiting the star HD 189733 A on October 5, 2005, when astronomers in France observed the planet transiting across the face of the star. With a mass 13% higher than that of Jupiter, HD 189733 b orbits its host star once every 2.2 days at an orbital speed of 152.5 kilometres per second (341,000 mph), making it a hot Jupiter with poor prospects for life as we know it. Being the closest transiting hot Jupiter to Earth, HD 189733 b is a subject for extensive atmospheric examination. HD 189733 b was the first extrasolar planet for which a thermal map was constructed, to be detected through polarimetry, to have its overall colour determined (deep blue), to have a transit detected in x-ray spectrum and to have carbon dioxide detected in its atmosphere.

Scientists estimate its temperature reaches almost 3,700 degrees Fahrenheit.

HD 189733b orbits its host start every 2.2 days, at a breakneck speed of 341,000 mph.


Scientists at the University of Warwick were able to measure velocities on the day and night sides of the planet. They discovered the 5,400 mph wind blowing from the day to the night side.

“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,” lead researcher Tom Louden said in a statement. “This is the first ever weather map from outside of our solar system.”

Exoplanet HD 189733b

Exoplanet HD 189733b

Astronomers used HARPS, the High Accuracy Radial velocity Planet Searcher, in La Silla, Chile, to watch the planet as it passed in front of its host star, relative to the telescope’s line of sight.

“The surface of the star is brighter at the center than it is at the edge, so as the planet moves in front of the star the relative amount of light blocked by different parts of the atmosphere changes. For the first time we’ve used this information to measure the velocities on opposite sides of the planet independently, which gives us our velocity map,” Louden said.

The Exoplanet HD 189733b research is being published in the Astrophysical Journal Letters.