An oceanic exoplanet discovered in part thanks to Quebec researchers

A new exoplanet composed of 30% water has been discovered in part thanks to the Mont-Mégantic Observatory. It is located 100 light years from Earth and could be habitable.

Mathieu Perreault
The Press

“We know a handful of potentially oceanic exoplanets, and this one seems the best candidate,” explains René Doyon, an astrophysicist at the University of Montreal, who is one of the co-authors of the study published last week in The Astronomical Journal. “We know that certain moons of Saturn and Jupiter, such as Europa, Enceladus or Ganymede, have a similar density and are covered with icy water. If they were located closer to the Sun, they would probably be covered with liquid water. »

The exoplanet, called TOI 1452b, orbits a star four times smaller than our Sun. It was discovered two years ago by NASA’s TESS space telescope, then its existence was confirmed by the Mont-Mégantic Observatory. Then, the SPIRou instrument (infrared spectropolarimeter) of the Canada-France-Hawaii telescope analyzed its mass and its radius. SPIRou was designed at the Mont-Mégantic Observatory.

TOI 1452b is 70% larger than Earth but appears to be only 4.8 times more massive. This could mean that it is composed of between 10% and 25% water, while the Earth contains only less than 1% water.

The star TOI 1452 is part of a double solar system, with another star, in the constellation of the Dragon. TOI 1452’s twin is located 97 astronomical units, the distance between Pluto and the Sun (or 15 thousandths of a light-year). “Our observations have allowed almost certain confirmation that it is a binary system,” says Mr. Doyon. It is a particular system, which is located in a region of the sky which is almost always observable. It made the measurements easier. »

Hydrothermal pits

If TOI 1452b is habitable, what form could life have there? “Some theories suggest that life originated at the bottom of the oceans, near hydrothermal vents,” says Doyon. There is an abundance of life there. And some branches of the oldest bacteria can live in extreme environments. »

The next step is the observation of TOI 1452b by the James Webb Space Telescope, which will be able to confirm the presence of liquid water. “We have to see if that much water can survive for a long time on planets in the habitable zone,” says Doyon.