Planets’ discovery can tell us
FOUR newly discovered planets could help scientists learn more about how the Earth and our solar system developed during their “teenage” years.
The exoplanets are about 130 light years away and orbit the stars TOI 2076 and TOI 1807, in the constellations of Boötes and Canes Venatici.
Both stars are K-type dwarfs believed to have been born in the same gas cloud about 200 million years ago.
Astronomers said the four worlds, which are two to four times the size of the Earth are in the early stages of creation and could reveal more about how young planets and planetary systems evolve.
They were discovered jointly by researchers from Loughborough University and more than 25 other institutes, led by Nasa.
“The planets in both systems are in a transitional, or teenage, phase of their life cycle,” said Christina Hedges, an astronomer at the Bay Area Environmental Research Institute in Moffett Field, in California.
“They’re not newborns, but they’re also not settled down.
“Learning more about planets in this teen stage will ultimately help us understand older planets in other systems.”
Loughborough student Alex Hughes brought TOI 2076 to astronomers’ attention in 2019, while working on an undergraduate project looking for light curves.
Using Nasa data, he found light from the star dipped periodically – possibly indicating the presence of exoplanets.
After contacting Dr Hedges, a
multinational collaboration discovered three worlds orbiting the star.
The innermost planet, TOI 2076b, is about three times Earth’s size and circles its star every 10 days.
Outer worlds, TOI 2076c and d, are a little over four times larger than Earth, with orbits of more than 17 days.
The second star, TOI 1807, hosts only one known planet, TOI 1807b, which was detected by Nasa in 2020. It is about twice Earth’s size and orbits the star in just 13 hours.
Alex, who is now studying for a masters in physics at UCL, said: “Discovering a planetary system that exists in this transitional teenage period gives us a chance to test our models of this early evolution period and probe some of the questions we still have.
“I believe TOI 2076 and TOI 1807 will help us better understand early formation and evolution processes, such that we can understand how our own solar system came to be.”
Dr Shaun Atherton, of Loughborough’s School of Science, was involved in the identification. He said: “This discovery is important for two reasons.
“One is the age of the two stars. Investigating both the stars and their planets at this stage of evolution will give insights into our own solar system’s early evolution.
“Second is the common origin of the two stars. Born in the same gas cloud, but having since moved apart, we can learn about how these two star systems have developed separately.”
A paper has been published in the Astronomical Journal.