NASA's planet-hunting TESS mission just launched last April on a Space X Falcon 9 rocket, but it's already making promising discoveries. According to asteroseismologists at Iowa State University, data collected by TESS have led to the discovery of a new Saturn-sized planet.
A team of asteroseismologists — astronomers who study seismic waves, also called "starquakes" — have found and characterized the first planet identified by TESS with a host star with measurable oscillations.
The planet is being called TOI 197.01 — TOI is short for "TESS Object of Interest" — and is described as a "hot Saturn" in a scientific paper written by a team of 141 astronomers, to be published in the Astronomical Journal. The planet is similar in size to Saturn and is very close to its star, completing an orbit in just 14 days, which creates a high surface temperature.
The team determined TOI-197.01 to be about 5 billion years old and a little heavier and larger than the sun. It is a gas planet with a radius about nine times that of Earth, making it about the same size as Saturn. It is also 1/13th the density and about 60 times the mass of Earth.
"TOI-197 provides a first glimpse at the strong potential of TESS to characterize exoplanets using asteroseismology," the astronomers wrote in their paper.
"This is the first bucketful of water from the firehose of data we're getting from TESS," physics and astronomy professor Steve Kawaler said.
TESS — the Transiting Exoplanet Survey Satellite and a successor to NASA's Kepler space telescope — launched from Florida's Cape Canaveral Air Force Station on April 18, 2018. Its primary mission is to find planets outside of our social system, called exoplanets. After two years, TESS will have scanned 85 percent of the sky using four cameras.
The goal is to identify planets that could support life. Astronomers are searching for stars hosting relatively small, Earth-like planets orbiting in the habitable zones of their suns at distances that allow water to exist as a liquid — a requirement for life as it is known on Earth. This week, astronomers created a list, published in the Astrophysical Journal Letters, of 408 stars that seem most capable of supporting planets in the habitable zone.
"Missions like TESS will help us keep learning so that eventually we can answer the question, are we alone?" said Paul Hertz , director of astrophysics at NASA Headquarters, after TESS' launch. "Or do we just have the best prime real estate in the galaxy?"