Scientists from Princeton University and NASA have confirmed that 1,284 objects observed outside Earth’s solar system by NASA’s Kepler spacecraft are indeed planets. Reported in The Astrophysical Journal on May 10, it is thelargest single announcement of new planets to date and more than doubles the number of confirmed planets discovered by Kepler so far to more than 2,300.
The researchers’ discovery hinges on a technique developed at Princeton that allows scientists to efficiently analyze thousands of signals Kepler has identified to determine which are most likely to be caused by planets and which are caused by non-planetary objects such as stars. This automated technique — implemented in a publicly available custom software package called Vespa — computes the chances that the signal is in fact caused by a planet.
The researchers used Vespa to compute the reliability values for over 7,000 signals identified in the latest Kepler catalog, and verified the 1,284 planets with 99 percent certainty. They also independently verified 651 additional planet signals that had already been confirmed as planets by other methods. In addition, the researchers identified 428 candidates as likely “false positives,” or signals generated by something other than a planet.