A team of astronomers has identified TOI-1452 b, an exoplanet located about 100 light-years from Earth that could contain enormous amounts of water. Based on its size, mass and density, researchers believe it may be one of the best ocean planet candidates found so far.
The world orbits a small star in a binary system in the constellation Draco. The discovery combines data from NASA’s TESS space telescope and several ground-based observatories.
TOI-1452 b is slightly larger than Earth and much more massive, with an estimated mass close to five times of Earth. Its orbit places it at a distance from its star where temperatures could allow liquid water to exist.
A Signal Spotted by TESS
The story began with observations from NASA’s TESS telescope, which searches for planets by detecting tiny drops in a star’s brightness. According to the Université de Montréal, researchers noticed a recurring signal every 11 days, pointing to the presence of a planet about 70% larger than Earth.
Confirming that signal was not straightforward. The host star is part of a binary system, and TESS sees both stars as a single source of light. To sort things out, the team used thePESTO camera at the Observatoire du Mont-Mégantic.
Those observations showed that the planet orbits the larger of the two stars.
“This was no routine check,” Charles Cadieux from the Université de Montréal said, “We had to make sure the signal detected by TESS was really caused by an exoplanet circling TOI-1452.”
A Planet That Doesn’t Look Much Like Earth
Once the newly world was confirmed, astronomers turned to SPIRou, an instrument at the Canada-France-Hawaii Telescope, to estimate its mass. That work required more than 50 hours of observations.
The measurements indicate that TOI-1452 b has a mass nearly five times that of Earth. Researchers also used a data-processing technique called the LBL method, developed by Étienne Artigau and Neil Cook, to isolate its faint signal.
As explained by the research team, the planet’s density is lower than what would normally be expected for a world made mostly of rock and metal. That result immediately made this exoplanet stand out from many other rocky celestial bodies discovered to date.
Water Could Account For A Large Part Of The Planet
The most striking possibility is the amount of water the planet may contain. As explained in the study, published by The Astronomical Journal, Earth is actually a very dry one in terms of overall mass, with water representing less than 1%.
For TOI-1452 b, things may be very different. Models produced by University of Toronto researchers Mykhaylo Plotnykov and Diana Valencia suggest that water could make up as much as 30% of the planet’s mass.
Following the Université de Montréal’s findings that estimate makes TOI-1452 b one of the strongest ocean planet candidates identified so far. Scientists compare that potential composition to several water-rich moons in our Solar System, including Ganymede, Callisto, Titan and Enceladus.
The planet is also considered a good target for future observations with the James Webb Space Telescope. Its relative proximity to Earth and its position in the sky make it particularly accessible for further study, which could help researchers better understand the nature of this unusual world.
