An international team of astronomers has identified an intriguing exoplanet with an abnormally eccentric orbit around its host star.

The celestial body, known as TOI 2257 b, may have the required characteristics to host liquid water.

The TOI 2257 b has a radius 2.2 times that of the Earth and takes 35 days to complete its orbit around its star, making it a lot cooler than the Sol-red dwarf. However, what drew experts’ attention was the shape of its trajectory: it turned out to be the most eccentric (elliptical) in the history of observations, resulting in a temperature range of 80 degrees below zero to 100 degrees, depending on location.

“In terms of potential habitability, this is bad news,” says study lead author Nicole Schanche of the University of Bern.

While the planet orbits its host star at a distance that allows for the possibility of liquid water, it is doubtful that it is also home to life, they add, because its radius indicates that it is a mainly gaseous planet with high atmospheric pressure. the authors of the study.

But what explains the exoplanet’s unusual orbit? The researchers believe that the presence of a hypothetical massive planet in the system could influence its orbit and, as a result, alter its trajectory.

Exoplanets beyond the solar system cannot be observed directly with a telescope due to their small size and lack of light reflection. During the study, astrophysicists used the transit method to examine decreases in stellar brightness caused by an exoplanet entering the field of view between Earth and its host star. They also used data from Mexico’s SAINT-EX telescope, which was built expressly to investigate red dwarfs and associated exoplanets.

“SAINT-EX was able to observe the entire transit, which gave us even more information about the properties of the system,” shares Robert Wells of the Swiss CSH observatory.

Source: 10.1051/0004-6361/202142280

You were reading: Most ‘eccentric’ exoplanet ever observed could host water