NASA probe provides more information about TRAPPIST-1

NASA's Kepler mission has provided more information about the recently discovered ultra-cool dwarf star, TRAPPIST-1, that hosts seven potentially habitable Earth-size planets 40 light-years away.

On February 22, astronomers announced that TRAPPIST-1 hosts a total of seven planets that are likely rocky, a discovery made by NASA's Spitzer Space Telescope in combination with ground-based telescopes. During the period between December 15 and March 4, the Kepler spacecraft, operating as the K2 mission, collected data on the star's minuscule changes in brightness due to transiting planets.

These additional observations are expected to allow astronomers to refine the previous measurements of six planets, pin down the orbital period and mass of the seventh and farthest planet, TRAPPIST-1h, and learn more about the magnetic activity of the host star.

"Scientists and enthusiasts around the world are invested in learning everything they can about these Earth-size worlds," said Geert Barentsen, K2 research scientist at NASA's Ames Research Centre in California.

"Providing the K2 raw data as quickly as possible was a priority to give investigators an early look so they could best define their follow-up research plans. We're thrilled that this will also allow the public to witness the process of discovery," said Barentsen.

The release of the raw, uncalibrated data collected will aid astronomers in preparing proposals due this month to use telescopes on the Earth to further investigate TRAPPIST-1, NASA said.

By late May, the routine processing of the data will be completed and the fully calibrated data will be made available at the public archive, it said.

The observation period, known as K2 Campaign 12, provides 74 days of monitoring. This is the longest, nearly continuous set of observations of TRAPPIST-1 yet, and provides researchers with an opportunity to further study the gravitational interaction between the seven planets, and search for planets that may remain undiscovered in the system.

During Campaign 12, a cosmic ray event reset the spacecraft's onboard software causing a five-day break in science data collection, NASA said. The benign event is the fourth occurrence of cosmic ray susceptibility since launch in March 2009. The spacecraft remains healthy and is operating nominally. "We were lucky that the K2 mission was able to observe TRAPPIST-1," said Michael Haas, science office director for the Kepler and K2 missions at Ames.

"The observing field for Campaign 12 was set when the discovery of the first planets orbiting TRAPPIST-1 was announced, and the science community had already submitted proposals for specific targets of interest in that field," said Haas.