Astronomers Discover Apparent "Ocean World" About 100 Light-Years Away from Earth

Recently, an international team of researchers led by Charles Cadiaux announced the discovery of the TOI-1452b exoplanet, located about 100 light-years away from Earth. 

This exoplanet is hypothesized to be a small star in a binary system located in the Draco constellation.

This exoplanet is slightly larger in size and mass than Earth. It is located at some distance from its star, as is Earth. Therefore its temperature will neither be too high nor too low.

Astronomers believe that it could be an ocean world that could be a planet completely covered by a thick layer of water - something like some of the moons of Saturn and Jupiter in our solar system. This research was published in The Astronomical Journal.

"I am very proud of this discovery because this discovery demonstrates the high potential of our researchers and instrumentation," said René Doyen, Université de Montréal Professor and Director of IREX and Observatoire du Mont-Mégantique (OMM).

"It is thanks to OMM, a special instrument designed in our laboratories called SPIRou, and an innovative analytical method developed by our research team that we were able to detect such a one-of-a-kind exoplanets."

It is NASA's space telescope TESS, which surveys the entire sky looking for planetary systems close to our own, that put researchers on the trail of this exoplanet.

Based on the TESS signal showing a slight decrease in brightness every 11 days, astronomers predicted a planet about 70% larger than Earth. 

Charles Cadiaks belongs to a group of astronomers conducting ground follow-up observations of the candidates identified by TESS to confirm their planet types and characteristics.

He uses PESTO, a camera installed on OMM's telescope designed by Professor David Lafrenier of the Université de Montréal and his Ph.D. was developed by a student François-René LaChapelle.

"The OMM was instrumental in confirming the nature of this signal and in estimating the radius of the planet," explained Cadiaux. "This was not a routine probe. 

We had to be sure that the signal detected by TESS was actually caused by the exoplanet orbiting TOI-1452, the largest of the two stars in that binary system."

The host star TOI-1452 is significantly smaller than our Sun and is one of two stars of similar size in the binary system. 

The two stars orbit each other and are separated by such a small distance—97 astronomical units, or about two and a half times the distance between the Sun and Pluto—that the TESS telescope sees them as a single point of light.

But Pesto's resolution is high enough to separate the two objects, and the images showed the exoplanet orbiting TOI-1452, which was confirmed through subsequent observations by a Japanese team.

A water world

The exoplanet TOI-1452 b is probably rocky planet like Earth, but its radius, mass and density suggest a world very different from our own.

Earth is essentially a very dry planet; Even though we sometimes call it the Blue Planet because about 70% of its surface is covered by ocean, water actually only makes up a negligible fraction of its mass less than 1%.

Water may be more abundant on some exoplanets. In recent years, astronomers have identified and determined the radius and mass of several exoplanets with the size of Earth and Neptune (about 3.8 times larger than Earth).

Some of these planets have densities that can only be explained if a large portion of their mass is made up of lighter materials that make up Earth's internal structure, such as water. These fictional worlds have been called "ocean planets".

"TOI-1452b is one of the best candidates for an oceanic planet we've found to date," Cadiaux said. "Its radius and mass suggest a much lower density than would be expected for an Earth-like planet originally composed of metal and rock."

"Our observations with the Webb telescope will be essential to better understand TOI-1452 b," said Doyn, who observed the concept of NIRISS, a component of James Webb. "As soon as we can, we will book time on the web to see this strange and wonderful world."