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KEYWORDS: PHYSICAL GEOGRAPHY, SCIENCE & TECHNOLOGY.

Spin Cycle: Astronomers Detect Distant Planet that Whirls Madly-- Beta Pictoris b

Scientists said on Wednesday that for the first time, they have measured the spin of a planet outside our solar system - a large gas planet located a relatively close 63 light years from Earth.

They determined that the planet spins faster than any in our solar system, with a rotational velocity at its equator of about 56,000 miles per hour (almost 100,000 kph).

Jupiter, a large gas planet that has the quickest spin in our solar system, whirls at about 29,000 miles per hour (47,000 kph) while Earth spins at about 1,000 miles per hour (1,700 kph). A day on Beta Pictoris b lasts only eight hours, compared to 10 hours for Jupiter and 24 hours for Earth.

Beta Pictoris b is one of the better understood of these planets. It is one of only about a dozen that have been directly observed rather than found using indirect detection methods

Beta Pictoris b is big, hot and young. It is about 3,000 times more massive than Earth and seven times more massive than Jupiter, our solar system's largest planet. It is only about 20 million years old, compared to about 4.5 billion years for Earth, and is still hot from its formation, the scientists said.

Its host star, Beta Pictoris, is approximately twice as massive and 10 times as luminous as our Sun.

THE BIGGER(MASSIVE)  PLANET ROTATES FASTER--- Need to observe more planets to confirm this is really a universal law.

The technique the scientists used to measure the planet's spin was based on the Doppler effect, the well-known phenomenon people notice when they hear a change in the pitch of an ambulance siren when the vehicle whizzes by.

                          

"When we observe a rotating planet, the light from one half, which is approaching us, has a slightly different frequency, or color, than the other half, which is receding from us. The relative difference in color, or frequency, between the two halves is a measure of the spin-rotation velocity,"