“This exoplanet was observed as a microlensing event in 2007,” said Dr. David Bennett of the NASA Goddard Space Flight Center.The discovery, named OGLE-2007-BLG-349, was found by the Optical Gravitational Lensing Experiment (OGLE) Collaboration Early Warning System and proclaimed on July 2, 2007. OGLE hunts for and detects effects from minor alterations of spacetime, produced by exoplanets and stars, which were foretold by Albert Einstein via the theory of General Relativity. These little distortions are now known as microlensing.
“The ground-based observations suggested two possible scenarios for the three-body system: a Saturn-mass planet orbiting a close binary star pair or a Saturn-mass and an Earth-mass planet orbiting a single star,” Dr. Bennett explained.Hubble images of the system OGLE-2007-BLG-349L. Image credit: D.P. Bennett et al. The image sharpness from Hubble’s Wide Field Planetary Camera 2 permitted the astronomers to isolate the background source star as well asthe lensing star from their neighboring space objects in the crowded star field. The observations revealed that the glow from the forefront lens system was very faint for a single star, but it had enough brightness for two narrowly orbiting red dwarf stars, which should be fainter and has less mass compared to our Sun.
“So, the model with two stars and one planet is the only one consistent with the Hubble data,” Dr. Bennett said. “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,” said Dr. Andrzej Udalski from the University of Warsaw, Poland.Now that the research team has proven that microlensing can successfully sense events triggered by circumbinary planets, Hubble could now provide a vital role in this new dominion in the never-ending search for exoplanets. The research paper announcing this discovery has been accepted in the Astronomical Journal for publication.
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