In the Draco constellation, about 100 light-years from Earth, an exoplanet orbiting one of two red dwarf stars in a binary system. Announcing its discovery the astronomers say that the planet TOI-1452 b could be a water world.
An international team of researchers led by Charles Cadieux, a Ph.D. student at the Université de Montréal and member of the Institute for Research on Exoplanets (iREx) has discovered the Super Earth- slightly greater in size and mass than Earth, orbiting the host star at a distance where the temperature is ideal for liquid water to exist on its surface. According to the astronomers, the planet could be an “ocean planet”— completely covered by a thick layer of water.
“I’m extremely proud of this discovery because it shows the high calibre of our researchers and instrumentation,” said René Doyon, Université de Montréal Professor and Director of iREx and of the Observatoire du Mont-Mégantic (OMM).
“It is thanks to the OMM, a special instrument designed in our labs called SPIRou, and an innovative analytic method developed by our research team that we were able to detect this one-of-a-kind exoplanet.”
TOI-1452 b takes just 11 days to complete an orbit around its host star, meaning just 11 days make a year on the planet. Astronomers used NASA’s space telescope TESS to find the planet that shows a slight decrease in brightness every 11 days, also helping them to predict the planet that is about 70% larger than Earth.
A ground-based Mont Mégantic Observatory’s (OMM) telescope helped astronomer Charles Cadieux and the team to confirm the TESS-identified TOI-1452 b’s type and characteristics. This team of astronomers used the PESTO camera mounted on OMM to observe the planet.
“The OMM played a crucial role in confirming the nature of this signal and estimating the planet’s radius,” said Cadieux. “This was no routine check. We had to make sure the signal detected by TESS was really caused by an exoplanet circling TOI-1452, the largest of the two stars in that binary system.”
TOI-1452, the host star of the planet is a lot smaller than our Sun, inhabiting another star of a similar size in the binary system. The mass of these two stars orbiting each other is very small allowing them to orbit at a smaller distance— about 97 astronomical units, roughly two and a half times the distance between the Sun and Pluto. The exoplanet’s orbit was also confirmed in subsequent observations by a Japanese team.
TOI-1452 b could be a rocky planet like Earth. However, its size and mass, density are greater than our home planet. Despite the 70% surface water covered in our Blue Planet, it only makes up about 1% of the planet’s mass.
“TOI-1452 b is one of the best candidates for an ocean planet that we have found to date,” said Cadieux. “Its radius and mass suggest a much lower density than what one would expect for a planet that is basically made up of metal and rock, like Earth.”
A simulation of TOI-1452 b created by The University of Toronto’s Mykhaylo Plotnykov and Diana Valencia shows that water could make up as much as 30% of its mass— similar to the water riched moons in our solar system such as Jupiter’s moons Ganymede and Callisto, and Saturn’s moons Titan and Enceladus.
The astronomers believe that TOI-1452 b is a perfect candidate for further observation with the James Webb Space Telescope which will unfold several questions.
“Our observations with the Webb Telescope will be essential to better understanding TOI-1452 b,” said Doyon who overviewed the conception of James Webb’s component NIRISS. “As soon as we can, we will book time on Webb to observe this strange and wonderful world.”
The original article of the study was published on August 12 2022 in The Astronomical Journal.