In a major announcement this week, researchers with the Kepler Space Telescope science team have confirmed the existence of 1,284 new planets that had originally been found by Kepler. This is a huge leap in the number of confirmed planets, bringing the total to over 2,300.
The previous science data collection done by Kepler was completed in 2013, so why is this new news? Well the exciting part is that these are confirmed planets. Usually when Kepler detects a signal indicating a potential planet, it needs to be verified by using some of the larger ground-based telescopes. Kepler is not immune to false positives, there are certainly cases where a Kepler detection is due to natural variations in a star’s light, especially since the instrument is so sensitive. A prime example of this is binary star systems, where two stars orbit one another, causing changes in perceived light.
The real gem of the discovery is that the planets were not painstakingly confirmed with a ground-based telescope like Gemini or Keck. The results come from a new statistical test by researchers at Princeton University. The test, a software package called Vespa, looks at a Kepler signal and determines the likelihood of it being a true planet detection. So how likely are these 1,284 new signals to be planets?
They reached a 99% likelihood of being a true detection. So the researchers say that these are all planets with 99% confidence. It’s also important to mention that 700 previous planetary discoveries, already confirmed, were verified by the new method, and 428 candidates were also identified as false positives.
“Vespa is a culmination of a change in attitude about how we deal with these large-data surveys,” says Timothy Morton, Princeton associate research scholar of astrophysical sciences. “This new problem Kepler created is that we now have thousands of new planet candidates. Astronomers knew we couldn’t follow up all of these in the traditional way, but there was nothing to replace it. This result now puts a number on exactly how likely it is that each detected object is a planet.”
This verification method can confirm most planets as true detections immediately, allowing major telescopes to follow up with future studies or focus on less confident detections. It’s a great way to manage the huge amount of data generated by Kepler and it’s successors. Future generations will look back at this period of time as the first leap in discovering alien worlds. It’s an exciting time to be an astronomer.