Discovering Kepler’s Final Legacy: Unveiling the Last Exoplanets Observed by the Telescope

A team of astronomers from MIT, the University of Wisconsin, and a group of amateur scientists may have discovered the final planets observed by the Kepler telescope before it ceased operations in 2018. Examining data from its last observation campaign, the experts gathered information from 500,000 stars before the telescope ran out of fuel. “Our goal was to extract any valuable insights from this limited dataset,” said Andrew Vanderburg, assistant professor at MIT, who, along with Elyse Incha, the study’s lead author, presented the challenge to the Visual Survey group comprising amateur and professional astronomers.

Collaboratively, they aimed to identify potential exoplanets within the satellite data by analyzing the light curves of each star observed. By filtering out noise and instrument failures, they meticulously examined the light curves of approximately 33,000 stars. Utilizing high-quality data obtained in the week prior to the telescope losing focus, the researchers discovered planetary transit signals on three distinct stars. A planetary transit occurs when a planet passes in front of its star, temporarily blocking its light. Eventually, the team identified two planets and confirmed them using data from the TESS telescope. One of these planets, K2-416 b, is 2.6 times larger than Earth and orbits its star every 13 days, while K2-417 b has nearly triple Earth’s size and completes one orbit every 6.5 days. Another candidate, EPIC 246251988 b, still requires confirmation through further observations. “We likely discovered the final planets observed by Kepler, using data taken during its last moments of operation,” concluded Vanderburg. These findings were detailed in a paper published in the Monthly Notices of the Royal Astronomical Society.