Astronomers have identified a new exoplanet they describe as a "hot Saturn" using data from NASA's Transiting Exoplanet Survey Satellite, better known as TESS.
The exoplanet called TESS Object of Interest or TOI-197.01 probably does not have the characteristic rings of Saturn. However, it is about the size of the gas giant and is also orbiting very close to its star, therefore, extremely hot.
"This is the first bucketful of water from the firehose of data we're getting from TESS," said Steve Kawaler, a professor of physics and astronomy.
A team of international astronomers will publish a paper on the new discovery on The Astronomical Journal. The paper also appears in the pre-publication site arXiv.
TESS Spots Hot Saturn
TESS monitors the night sky and searches for temporary dips in brightness, which usually means that an exoplanet is orbiting a distant star. The spacecraft has four cameras aimed at a section of the sky to look for transits.
The new spacecraft works similarly to its predecessor, the retired Kepler Space Telescope. However, TESS surveys nearby stars, allowing astronomers to make follow-up observations using ground-based telescopes.
The team sorted through the trove of data that the telescope has been beaming back from its position in outer space to find these transits. They use asteroseismic modeling to determine the radius, mass, and age of a star based on the so-called "starquakes," some seismic waves of stars that manifest as changes in stars' brightness. By combining these data to other observations, astronomers are able to learn about the properties of an exoplanet.
TOI 197, according to the study, is about 5 billion years old. It is a gas giant like Saturn. It is a little heavier and larger than the sun. It has a radius about nine times of Earth, about 1/13th of the density of Earth, and about 60 times the mass of Earth. Moreover, it completes a revolution around its star after 14 days.
A Worthy Successor To Kepler
"The thing that's exciting is that TESS is the only game in town for a while and the data are so good that we're planning to try to do science we hadn't thought about," Kawaler said. "Maybe we can also look at the very faint stars — the white dwarfs — that are my first love and represent the future of our sun and solar system."