An exoplanet possibly covered by an ocean discovered by a Quebec team

Named TOI-1452b, the planet discovered by PhD student Charles Cadieux and his colleagues is slightly larger and more massive than Earth.

The first information gathered suggests that it would be an oceanic world entirely covered with a thick layer of water.

Artistic representation of the surface of the exoplanet TOI-1452 b, which is possibly entirely covered by a thick layer of liquid water.

Photo: University of Montreal/Benoît Gougeon

It is at a distance from its star that allows it to maintain a temperature that is neither too hot nor too cold for liquid water to exist on its surface.notes the press release published by the iREx.

While it’s probably rocky like Earth, its radius, mass, and density suggest it’s a very different world from our planet.

Earth is a particularly arid planet. Although it is sometimes nicknamed the blue planet in reference to the oceans which cover some 70% of its surface, water accounts for only a negligible fraction of its mass, less than one percent.the statement added.

However, the analyzes of TOI-1452 b show that the fraction of the water mass of the planet would reach 30%.

The researchers explain that this fraction is similar to that of certain natural satellites of the solar system such as Ganymede and Callisto, moons of Jupiter, or Titan and Enceladus, moons of Saturn.

The frozen surface of Enceladus, a moon of Saturn, as seen by the Cassini spacecraft.

Saturn’s moon Enceladus contains similar amounts of water to exoplanet TOI-1452 b.

Photo: NASA/JPL/Space Science Institute

Several exoplanets detected in recent years have a density that can only be explained if a large fraction of the mass is made up of materials that are lighter than those that make up the internal structure of the Earth, such as water. It would thus be ocean planets.


  • No less than 5071 exoplanets have been officially detected in more than 3799 planetary systems.
  • More than 8870 additional exoplanets are currently awaiting confirmation.
  • According to the most recent estimates, there are up to 700 million billion rocky planets in the observable Universe alone.
  • Nearly two-thirds of all exoplanets known to date, Earths and super-Earths, are located in the habitable zone of their stars.

Around a little star

The planet is in orbit around the star TOI-1452. Much smaller than the Sun, it sits in a dual system that includes another star of similar size.

It was from data collected by NASA’s TESS space telescope that the Quebec team was put on the trail of the exoplanet.

TESS observations suggested that a planet about 70% larger than Earth could be in this binary system, as a slight decrease in the star’s brightness was observed every 11 days.explains the press release.

In fact, the two stars orbit each other and the distance between them (about two and a half times the distance between the Sun and Pluto) is so small that the TESS telescope only sees them as one. single point of light. The resolution of the PESTO camera, installed on the telescope of the Mont-Mégantic observatory, made it possible to distinguish them and to confirm that a planet was indeed revolving around the star TOI-1452.

Mont-Mégantic Observatory

Mont-Mégantic Observatory

Photo: Courtesy / Sébastien Giguère/International Dark Sky Reserve of Mont-Mégantic

The Mont-Mégantic Observatory played a crucial role in confirming the existence of this planet and determining its radius.says Charles Cadieux.

I am extremely proud of this discovery because it highlights the quality of astronomers and instruments heresays René Doyon, professor at the University of Montreal and director of the iREx and the Mont-Mégantic Observatory.

To determine the mass of TOI-1452 b, the team scanned the binary system with the SPIRou instrument, installed on the Canada-France-Hawaii Telescope in Hawaii.

SPIRou, designed at UdeM, is ideal for studying low-mass stars because it operates in the infrared, where these stars are most luminous.

Combined with an analysis method developed by the Quebec team, the SPIRou data collected after nearly 50 hours of observation made it possible to estimate the mass of the planet: it would be almost five times that of the Earth.

Professor Doyon believes that the new James Webb telescope can be used to determine more precisely the nature of TOI-1452 b.

As soon as we can, we will ask for time to observe this strange worldsays the professor.

The detail of this discovery is the subject of an article published in the Astronomical Journal (New window) (in English).

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