First exoplanet seen spinning

Astronomers have for the first time managed to detect the rotation of an extrasolar planet, by analysing the way its atmosphere filters light. This technique could also provide clues about planet formation.
Ignas Snellen and his colleagues at Leiden University in the Netherlands report in Nature¹ that a gaseous planet orbiting the star β Pictoris rotates at 25 kilometres per second at its equator — faster than any planet in the Solar System and about 50 times faster than Earth. A day on the planet, called β Pictoris b, lasts just over eight hours, even though the planet has a diameter more than 16 times that of Earth's and carries more than 3,000 times Earth's heft.