Astronomers studying stars are a valuable aid to the Planet Hunt astronomers, who are following the main objective of NASA's new TESS mission.
In fact, asteroseismologists ̵
This collaboration enabled the discovery and characterization of the first planet identified by TESS for which the vibrations of its host star can be measured.
The planet – TOI 197.01 (TOI is short for "TESS object of interest") – is called "hot Saturn". in a recently accepted scientific paper. That's because the planet is about the same size as Saturn and is also very close to its star and has completed an orbit in just 14 days and is therefore very hot.
The Astronomical Journal will publish the paper in writing by an international team of 141 astronomers. Daniel Huber, assistant astronomer at the University of Hawaii at the Manoa Institute for Astronomy, is the main author of the newspaper. Steve Kawaler, professor of physics and astronomy; and Miles Lucas, a undergraduate student, are co-authors of Iowa State University.
"This is the first bucket of water from the fire of data we receive from TESS," said Kawaler.
TESS Transit Exoplanet Survey Satellite, led by astrophysicists of the Massachusetts Institute of Technology, launched on April 18, 2018 from the Cape Canaveral Air Force Station in Florida. The main purpose of the spacecraft is to find exoplanets, planets outside our solar system. The four cameras of the spacecraft cast an almost month-long view of 26 vertical stripes of the sky – first over the southern hemisphere and then over the northern one. After two years, TESS will have scanned 85 percent of the sky.
Astronomers (and their computers) search the images and look for passages, the tiny collapses in the light of a star caused by a planet passing by. NASA's Kepler mission – a predecessor to TESS – searched for planets in the same way, but searched a narrow stretch of the Milky Way and focused on distant stars.
TESS targets bright, close stars so that astronomers can continue to follow. His discoveries use other spatial and ground observations to further explore and characterize stars and planets. In another article recently published online by The Astrophysical Journal Supplement Series astronomers from the TESS Asteroseismic Science Consortium (TASC) have identified a list of Sun-like oscillating stars (many that resemble our future Sun) with TESS data – a list of 25,000 stars.
Kawaler – who witnessed Kepler's launch in 2009 and was ready to launch TESS in Florida (but a last-minute delay meant he did not have to miss the launch to return to teaching Ames) – is on the seven-member TASC board. The group is led by Jørgen Christensen-Dalsgaard from Aarhus University in Denmark.
TASC astronomers use asteroseismic models to determine the radius, mass and age of a host star. These data can be combined with other observations and measurements to determine the properties of planets in orbit.
In the case of the host star TOI-197, the asteroseismologists used their vibrations to determine that they are about 5 billion years old and a bit heavier and slightly heavier than the sun. They also found that the planet TOI-197.01 is a gas planet whose radius is about nine times the size of the Earth, about the size of Saturn. It is also 1/3 of the Earth's density and about 60 times the mass.
These results say a lot about the forthcoming TESS work: "TOI-197 gives a first insight into the strong potential of TESS to characterize the use of exoplanets asteroseismology," astronomers wrote in their paper.
Kawaler expects that the flood of data from TESS will also contain some scientific surprises.
"The exciting thing is that TESS is the only game in the city where there is only one thing and the data is so good that we plan to do science that we did not think about," said Kawaler , "Perhaps we can also look at the very weak stars – the white dwarfs – who are my first love and represent the future of our solar and solar system."
The search for the next Earth-like planets is announced