NASA's planet-hunting TESS mission has only been surveying the sky since July, but it's already making incredible discoveries.
In January, three exoplanet discoveries were connected to the initial observations from TESS. Now, the data collected by TESS has located a new Saturn-size planet.
TOI (TESS Object of Interest) 197.01 is considered to be a "hot Saturn." It is similar in size to that planet and orbits its host star at a close distance, circling it every 14 days. This tight orbit creates a high surface temperature on the planet.
Asteroseismologists have discovered the planet by studying seismic waves called starquakes in stars where the brightness appears to shift. The astronomers can determine the age of the star, as well as its mass and radius.
The exoplanet is a gas giant with a radius nine times that of Earth and about 60 times Earth's mass. "The host star is 5 billion years old and slightly heavier and larger than our sun."
"This is the first bucket of water from the fire hose of data we're getting from TESS," said Steve Kawaler, study co-author and Iowa State University, Professor of Physics and Astronomy, in a statement. "The thing that's exciting is that TESS is the only game in town for a while and the data is so good that we are planning to try to do science that we did not think 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 the solar system. "
The Transiting Exoplanet Survey Satellite launched in April to take up the planet-hunting
TESS is 400 times larger than what Kepler observed, including 200,000 of the brightest nearby stars. Over the course of two years, the four wide-field cameras on the board will be stare at different sectors of the sky for days at a time.
This week, a team of astronomers identified a list of what might be the most promising stars to support planets in the habitable zone called the TESS Habitable Zone Star Catalog, which was published. in the Astrophysical Journal Letters.
The catalog includes 1,822 stars. TESS could observe where planets are slightly larger than Earth would exist in their star habitable zone. The habitable zone, called the Goldilocks Zone, is when the conditions are warm enough to allow liquid water to exist on the planet's surface. Liquid water is the foundation of life as we know it.
"Life could exist in all sorts of worlds, but the kind we know can support life is ours, so it makes sense to first look for Earth-like planets, "Said Lisa Kaltenegger, lead author and member of the TESS Science team at Cornell University, in a statement. "This catalog is important for TESS because anyone working with the data wants to know about which stars we can find the closest Earth analogues."
And 408 stars may support the planets Earth size that receive the same amount of radiation that we get from the sun.
"I have 408 new favorite stars," Kaltenegger said. "It's amazing that I do not have to pick one just;
There is also a subset of 227 stars in the catalog where TESS can conduct a wider search for cooler Mars-like planets to provide a larger range of worlds in the universe.
"We do not know how many planets TESS will find around the hundreds of stars in our catalog or whether they will be habitable," Kaltenegger said. "But the odds are in our favor. Some studies indicate that there are many rocky planets in the habitable zone of cool stars, like those in our catalog. We are excited to see what the worlds we find. "
TESS will look for exoplanets using the transit method, observing the slight dips in stars' brightness as the planets pass in front of them. Bright stars allow for easier followup studies through ground-based and space-based teleskops.
NASA expects TESS to allow cataloging more than 1,500 exoplanets, but it has the potential to find thousands. Of these, officials anticipate, 300 will be Earth-sized exoplanets or double-Earth-sized super Earths. These planets could be the best candidates for supporting life outside our solar system.
TESS is considered a "bridge to the future," finding exoplanet candidates to study more in detail.
These exoplanets will be explored so that NASA can determine the best targets for missions like the James Webb Space Telescope. That telescope, launching in 2021, would be able to characterize the details and atmospheres of exoplanets in ways that scientists have not been able to do.