WARSAW, Poland, Sept. 22 (UPI) -- New data from Hubble has confirmed the presence of an exoplanet circling a binary star system. A microlensing event observed in 2007 first alerted scientists to the planet's presence.
Most exoplanets are discovered by measuring the dimming of stellar light as exoplanets transit across the face of their host stars. NASA's Kepler mission uses the transit method.
The majority of its finds are exoplanets orbiting a solitary star. Only a handful of planets have been found in binary star systems.
The new exoplanet, whose presence was only recently confirmed, is doubly unusual.
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The alien world was initially spotted by scientists working on the Optical Gravitational Lensing Experiment, the OGLE mission. Gravitational lensing, or microlensing, is the name for the bending of light by an object's gravity.
The microlensing event, a trio of distortions dubbed OGLE-2007-BLG-349, was first observed in 2007, but scientists couldn't confirm the sources of all the spacetime irregularities.
Only recently -- with newly collected data from the Hubble Space Telescope -- were astronomers able to determine that there are two stellar sources being manipulated by a sizable exoplanet.
"OGLE has detected over 17,000 microlensing events, but this is the first time such an event has been caused by a circumbinary planetary system," Andrzej Udalski, an astronomer at the University of Warsaw, explained in a news release.
The Hubble data also confirmed the world as the lowest-mass circumbinary planet system known by astronomers.
Additionally, the combination of Hubble and OGLE observations and analyses promises a new and improved method for locating exoplanets orbiting far from their stars. Most planets found by Kepler follow intimate and stable orbits.
The new findings were published this week in the Astrophysical Journal.
"This discovery, suggests we need to rethink our observing strategy when it comes to stellar binary lensing events," said Yiannis Tsapras, researcher with the Astronomical Calculation Institute at Heidelberg University. "This is an exciting new discovery for microlensing."
