To find the planet, astronomers used Einstein's theory as it pertains to the intensity of a beam of light. The method could add more exoplanets to a growing list, no 'wobble' or 'transit' required.
With a little help from Einstein's theory of special relativity, astronomers have discovered a planet orbiting a star some 2,000 light-years away using a new approach that was barely a gleam in its proposers' eyes a decade ago.
The planet is a bit larger and about twice as massive as Jupiter. It orbits its sun-like star once every 1.5 days. The team making the discovery estimates the planet's temperature at a searing 3,600 degrees Fahrenheit.
On one level, such "hot Jupiters" are a dime a dozen these days. Because they are massive and close to their host stars, they are the easiest planets to spot with virtually every planet-hunting technique astronomers have used to date.
What sets this discovery apart, however, is that the planet is the first to have been found through a process that in some ways could simplify planet hunting, researchers say. Its effectiveness is limited to big planets orbiting close to their stars, the team reporting the discovery acknowledges.
But it also holds out the hope of finding such planets when the parent stars may be too faint for other, currently used techniques. This opens the possibility of adding many more extra-solar planets to a catalog that now tops 800 of them.
No need to hunt for the wobble a planet's gravity imparts to its star's spectrum. No need to wait for a planet to pass in front of its star, known as a transit.
Instead, the team looked for a combination of three relatively small effects that wax and wane throughout a planet's orbit around a star. This delivers a different signal to a planet-hunting device like NASA's Kepler spacecraft than the eclipsing planet, or transit method, delivers, notes David Latham, an astronomer at the Harvard-Smithsonian Center for Astrophysics and a member of the team discovering the planet.
"The transits last just a short time, just a couple of hours," Dr. Latham writes in an e-mail. But the effects the team tracked "rise and fall continuously through the entire orbital period of the planet, roughly 36 hours, so it’s not hard to distinguish these phenomena."