A Newly Discovered Ocean Exoplanet Is Right in the Habitable Zone Sweet Spot

Water, water everywhere. But could there be life on recently discovered exoplanet TOI-1452 b?
exoplanet

An international team of researchers recently found an exoplanet that might be covered entirely in water. They will study it more closely using the James Webb Space Telescope. This exoplanet could be a key to understanding how water worlds form and evolve. It could also help us understand the potential for life on other planets.

The researchers first guessed that there was an exoplanet in the Draco constellation based on data from the Transiting Exoplanet Survey Satellite (TESS). The exoplanet is called TOI-1452 b and is 100 light-years away in the Draco constellation. It orbits two M-type (red dwarf) stars that are 97 astronomical units (AUs) apart.

exoplanet b
TOI 1452 b. Credit: Benoit Gougeon, Université de Montréal.

Astronomers found the exoplanet while observing two stars in the TOI-1452 system. These stars appear as one point of light when observed by TESS. However, the high-resolution PESTO camera lens allowed it to distinguish the two objects, and the images it obtained confirmed that an exoplanet orbits TOI-1452.

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The astronomers and astrophysicists were from all over the world, including Brazil, Canada, France, Germany, Hungary, Japan, Portugal, Russia, Spain, Switzerland, and the United States. They worked together to study exoplanets, which are planets that orbit stars outside of our solar system.

These astronomers are interested in finding planets that have water because water is necessary for life. They are searching for planets beyond our solar system, and some of them might have oceans covering the entire surface. Scientists are not sure if those planets would be able to support life, but they are interested in these “ocean worlds” because they can teach us about habitability.

SPIRou telescope technology reveals more

The SPIRou telescope that the researchers were using is very good at seeing stars that are very dim. The team used SPIRou to learn more about the planet they found. They found out that the planet is very big, much bigger than Earth.

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Canada France Hawaii Telescope Sunset
Canada-France-Hawaii Telescope by Generic1139 under CC BY-SA 4.0

The astronomers noted that when observing TOI-1452 b it experienced a slight decrease in brightness every 11 days. From this observation, they could estimate that it has a diameter about 70% larger than Earth’s.

The researchers used a line-by-line (LBL) analysis method to analyze the data, which allowed them to find a weak signal produced by the exoplanet. Farbod Jahandar and Thomas Vandal, both Ph.D. students at Université de Montréal, then looked at the data to find out more about the star that the exoplanet is orbiting. Based on their estimates of the exoplanet’s radius, mass, and density, the astronomers think TOI 1452 b is probably a rocky planet.

Scientists conclude that TOI 1452 b is definitely a planet with oceans

A recent study found that the planet TOI 1452 b could be covered in a thick layer of water. Models made by Mykhaylo Plotnykov and Diana Valencia at the University of Toronto support this idea. They show that water may make up as much as 30% of TOI 1452 b’s mass. This is similar to other satellites like Jupiter’s moons Europa, Ganymede, and Callisto, and Saturn’s moons Titan, Dione, and Enceladus.

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Astronomers have found lots of planets that that have less mass and a lower density, similar to Earth. This suggests that these planets are mostly made up of water, which is why they are called “ocean planets.” The latest discovery may be the first planet that is definitely an ocean planet.

1024px NASA Exoplanet WaterWorlds 20180817
NASA-Exoplanet-WaterWorlds by NASA

TOI-1452 b is one of the few known temperate planets with the characteristics of an ocean planet. Since TOI-1452 b orbits within the HZ of its host star, it is unlikely to have a surface made of ice. Instead, it could have oceans that are several kilometers deep.

Temperatures and conditions on a temperate planet are neither too hot nor too cold for liquid water to exist on the surface. There are a few temperate planets we know about, but most of them don’t have oceans.

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This makes TOI-1452 b a great candidate for more observations with the JWST. Its closeness to Earth also makes it a good choice for studying the atmosphere, which is something Webb is very good at.

The great news for researchers is that this exoplanet is in a region of the sky that the James Webb Space Telescope (JWST) can observe year-round so that astronomers can study the planet in detail.