Astronomers at the 29th International Astronomical Union General Assembly will announce on August 14 the discovery of a new transiting “circumbinary” planet, bringing the number of such known planets into double digits. A circumbinary planet orbits two stars, and like the fictional planet “Tatooine” from Star Wars, this planet has two suns in its sky. The discovery marks an important milestone and comes only four years after the first Kepler circumbinary planet was detected. Once thought to be rare or even impossible, these ten discoveries confirm that such planets are common in our galaxy. The research was recently published in the Astrophysical Journal.
The new planet, known as Kepler-453 b, also presented astronomers with a surprising twist—the tilt of the orbit of the planet rapidly changes, making transits visible only 9 percent of the time. “The detection was a lucky catch for Kepler,” said William Welsh, professor of astronomy at San Diego State University and lead author of the study. “Most of the time, transits would not be visible from Earth’s vantage point.” The change of orientation of the planet’s orbital plane, known as precession, brought it into proper alignment halfway through the space telescope’s lifetime, allowing three transits to be observed before the end of the mission. “The low probability for witnessing transits means that for every system like Kepler-453 we see, there are likely to be 11 times as many that we don’t see,” added co-author Jerome Orosz, also a professor of astronomy at…