Astronomers have discovered a planet in the habitable zone of a red dwarf star, but its orbit is so long that it would have wildly variable temperatures and likely not support life.
The planet, called TOI-2257 b, was first observed using data from NASA’s TESS (Transiting Exoplanet Survey Satellite) and then observed in more detail using the Las Cumbres Observatory Global Telescope and the SAINT-EX telescope in Mexico. Using SAINT-EX observations, the researchers were able to confirm that a planet orbits the red dwarf star every 35 days, Digitartlends reports.
Because red dwarf stars are smaller and cooler than our Sun, the habitable zone around them, or the region where liquid water can exist on the surface of an orbiting planet, is also different. Planets that orbit red dwarf stars can contain liquid water even if they orbit near the Earth around the sun, and the planet’s presence near the star makes it easy to detect.
However, although TOI-2257 b is in the habitable zone, don’t make any plans to move there just yet. The first problem with habitability is that the planet has a radius of 2.2 times that of Earth, which means it is large and potentially gaseous with high atmospheric pressure.
The second and most interesting fact regarding this planet is that it has a highly eccentric orbit, which means that its orbit follows an ellipse or ellipse rather than a circle. Sometimes a planet is close to its star and other times it is far away. It also has the most eccentric orbit of a planet around a cold star ever discovered. And that has a huge impact on the surface temperatures there.
“We found that TOI-2257 b does not have a concentric circular orbit,” lead researcher Nicole Shanchy explained in a statement. Also, the average planet temperature ranges from -80 degrees Celsius to regarding 100 degrees Celsius depending on where the planet is in its orbit, far from or close to the star.”
Researchers are curious as to why the planet’s orbit is skewed, which might be due to a giant planet in the same system affecting that planet’s orbit. To find out more, researchers hope they can study the planet further with the James Webb Space Telescope.
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