TESS Mission Found a New Saturn-sized Planet called TOI 197.01

The TESS Mission of NASA has given some valuable insights to the planet-hunting astronomers by discovering TOI 197.01, a Saturn-sized planet.

It is a common observation that stellar astronomers who study starquakes in stars often end up in providing some useful information about the properties of newly-discovered planets. This time around, they managed to characterize a ‘Hot Saturn’ through the TESS Mission. TOI 197.01 is the first planet identified by TESS for which the oscillations of its host star can be measured. It is about the same size as Saturn but has an orbital period of only 14 days which makes it incredibly hot. Steve Kawaler, a Professor of Physics and Astronomy at the Iowa State University who is an Author of the paper, talked about the significance of this discovery and said,

“This is the first bucketful of water from the firehose of data we’re getting from TESS.”

Daniel Huber, an Assistant Astronomer at the University of Hawaii, led an international team of 141 researchers for this study that is going to be published in the ‘Astronomical Journal’.  

TOI 197.01

According to the researching team, the host star of TOI 197.01 is a little heavier and larger than our Sun and is around 5 billion years old. The age of TOI 197 was determined by referring to its oscillations. TOI 197.01 is 13 times less dense and 60 times more massive than the Earth. Its radius is 9 times our planet which makes it nearly as big as Saturn. Similarly, the fact that it is a gaseous planet urged the astronomers to nickname it as a ‘Hot Saturn’.

Potential of TESS

The Transiting Exoplanet Survey Satellite (TESS) was launched on 18^th April 2018 from the Cape Canaveral Air Force Station, in Florida. The astrophysicists from the Massachusetts Institute of Technology (MIT) led the launch. The primary goal of this mission is to find exoplanets (planets outside our solar system) that could support life. Basically, scientists are looking for relatively small, Earth-like planets that are orbiting in the habitable zones (distances that allow water to exist in liquid state) of their respective stars. Recently, astronomers created a list of 408 stars that seem most likely to host life-supporting exoplanets in their habitable zones. Paul Hertz, the Director of Astrophysics at NASA Headquarters, talked about the TESS Mission in the following words:

“Missions like TESS will help us keep learning so that eventually we can answer the question, are we alone? Or do we just have the best prime real estate in the galaxy?”

TESS spacecraft was launched as a successor of the Kepler Space Telescope with the intentions of exploring a much larger area than what Kepler did. The four cameras of TESS take nearly month-long images of the 26 vertical strips of the sky. The mission has been set up in a way that the spacecraft explores a strip by first going over the Southern Hemisphere and then move towards the northern part of the sky. It is estimated that it will cover nearly 85% of our sky in the first two years of its operation. TESS is targeting bright, nearby stars to follow up the discovery with other observations to further study and characterize stars and planets. On the other hand, Kepler scanned a small slice of the Milky Way and focused primarily on distant stars.

Role of TASC in Discovering TOI 197.01

Kawaler is a part of the TESS Asteroseismic Supplement Series (TASC) board, which identified the list of target stars that could potentially have habitable stars around them. This team of astronomers uses asteroseismic modeling to estimate the age, mass, and radius of the host star. Along with other measurements and observations, this information enables them to determine the properties of the orbiting planets. This is the technique that allowed the researchers to extract instrumental data about the host star of TOI 197.01. Astronomers mentioned that this is the first glimpse of what TESS can actually do. Kawaler referred to the potential of TESS by saying,

“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. 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.”