Kepler astronomers discover a treasure trove of 95 new exoplanets
The space-based Kepler telescope may have been hobbled by a mechanical failure in 2013, but it continues to gather data about the potential for Earth-size planets orbiting distant stars. Astronomers have now revealed the latest of Kepler’s findings: a haul of close to 100 exoplanets.
As part of the study, published in The Astronomical Journal, a team of international researchers poured over data from Kepler reaching back to 2014, honing on 275 “candidate” signals. These are measurements of drops in luminosity from distant stars, potentially caused by a planet passing in front of the light source, therefore momentarily lowering brightness.
“We found that some of the signals were caused by multiple star systems or noise from the spacecraft,” study lead author Andrew Mayo, a PhD student at the Technical University of Denmark’s National Space Institute, said in a statement. “But we also detected planets that range from sub-Earth-sized to the size of Jupiter and larger.”
Of the 275 candidates, 149 were deemed to be actual exoplanets, of which 95 were new discoveries. This doesn’t necessarily mean the other candidates are definitely not exoplanets, just that more evidence is needed to confirm. The impressive discovery is the result of several years of work from institutes including NASA, Caltech, UC Berkeley, the University of Copenhagen, and the University of Tokyo.
Of the 95 exoplanets, one of the most interesting is in the orbit of a particularly bright star: “We validated a planet on a 10 day orbit around a star called HD 212657, which is now the brightest star found by either the Kepler or K2 missions to host a validated planet. Planets around bright stars are important because astronomers can learn a lot about them from ground-based observatories,” said Mayo.
The findings are part of Kepler’s extended K2 mission, also known by the B-movie-reminiscent title, “Second Light”. In this stage of Kepler’s life, the space observatory periodically shifts its field of view to prevent radiation from the sun interfering with its balance.
The reason for this need to change position every 83 days or so is because the satellite suffered a major malfunction to its altitude-controlling reaction wheels. For a while, it looked like game over for Kepler, but it was decided in November 2013 that a new mission plan (K2) would keep up the search for exoplanets, but with a much larger area in the plane of Earth’s orbit around the sun.
The new haul brings Kepler’s total haul to 2,440 – around two-thirds of all alien planets discovered. K2 alone has been responsible for 292 of that number, and 2,000 additional candidates are waiting in the wings for follow-up observations. Some of those may involve video game players – with EVE Online’s pioneering Project Discovery mode allowing everyday people to help real scientists shift through masses of data relating to potential exoplanets.