Research presented today at the annual meeting of the American Astronomical Society indicates that circumbinary planetary systems–planets that orbit two stars–are not rare, rather that millions may exist in the Milky Way alone. At a press conference today, William Welsh of San Diego State University described Kepler 34b and Kepler 35b, the newest additions to this new class of planetary systems. The work is published in the January 12 issue of the journal Nature.
“The eclipses of the stars allow us to measure the properties of the stars with exquisite precision,” said Welsh, “which in turn allows us to measure the planet properties.”
The transits (small eclipses) caused by the planet provide the definitive proof of the planet’s existence, while the big eclipses of the stars allow scientists to measure the properties of the stars with precision. This, in turn, allows them to measure the planet properties.
Now that three such systems have been directly observed (Kepler 16b was announced in September) researchers have found a diversity of stellar and planetary orbits in this new class of planetary system, and are eager to investigate how planets form around a pair of stars.
With support from the National Science Foundation (NSF), Welsh’s research team will continue to search for more planets, both transiting and non-transiting. “We are by no means done,” he said, “and finding circumbinary planets is much harder than finding planets around single stars.”
