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Scientists discover world that spins so fast, a day is over in 8 hours

By Deborah NetburnLos Angeles Times

If you think 24 hours isn’t enough time to get everything done, here’s a little perspective: You could be living on a world with an eight-hour day.

For the first time, scientists have directly observed the spin of a planet outside our solar system, and determined it is spinning at the rate of 62,000 miles per hour. That’s about twice as fast as Jupiter, and more than 50 times as fast as Earth. A day is only eight hours long because the planet is much bigger than Earth.

The findings were published last week in the journal Nature.

The fast-spinning planet is known as Beta Pictoris b. It is young — just 20 million years old. (Earth is 4.5 billion years old.) It is also hot, and shines 10,000 times brighter than Jupiter.

It was a good candidate for this study because it is just 65 light-years from Earth, and because it orbits its star at about two times the distance between our sun and Jupiter, light from the star does not completely drown out the measurable light from the planet.

A team of Dutch astronomers from Leiden University and the Netherlands Institute for Space Research looked for blue and red shift caused by the Doppler effect in near-infrared spectroscopic observations made using the European Southern Observatory’s Very Large Telescope.

“Using this technique we find that different parts of the planet’s surface are moving towards or away from us at different speeds, which can only mean that the planet is rotating around its axis,” lead author Ignas Snellen said in a statement.