Despite a malfunction that ended its primary mission in May 2013, NASA’s Kepler spacecraft has discovered a new super-Earth using data collected during its “second life,” known as the K2 mission.
University of Hawaiʻi astronomer Christoph Baranec supplied confirming data with his Robo-AO instrument mounted on the Palomar 1.5-meter telescope, and former UH graduate student Brendan Bowler, now a Joint Center for Planetary Astronomy postdoctoral fellow at Caltech, provided additional confirming observations using the Keck II adaptive optics system on Maunakea.
During a nine-day test in February 2014 Kepler detected a single planetary transit. The newfound planet, HIP 116454b, has a diameter of 20,000 miles, two and a half times the size of Earth, and weighs almost 12 times as much as Earth. This makes HIP 116454b a super-Earth, a class of planets that doesn’t exist in our solar system.
During the process of verifying the discovery, Harvard astronomer and study co-author John Johnson, a former postdoctoral fellow at the UH Institute for Astronomy, contacted Baranec and the Robo-AO team to obtain high-resolution imaging of HIP 116454 to determine whether it has very nearby stellar companions that could be contaminating the Kepler data, causing a misestimation of the planet’s size and other characteristics.
“Because of the flexible nature of the Robo-AO system, it was possible to add the target to the Robo-AO intelligent queue and several observations were carried out within days of the request,” said Baranec.
While Robo-AO didn’t find any stellar companions, some additional follow-up measurements hinted that there might be a companion that is too close for Robo-AO to see. To be absolutely sure there were no contaminating companions, Bowler was asked to observe HIP 116454 with the Keck II adaptive optics system. He confirmed that HIP 116454 has no close-in stellar companions.
The research paper reporting this discovery has been accepted for publication in The Astrophysical Journal.
Read the Institute for Astronomy’s news release for more on the discovery.
—By Louise Good