A super-Earth around a red star could be wet and wild

Astronomers have spotted a potentially habitable exoplanet around a bright dwarf star. Odds are good we'll hear more about K2-155d in the future.

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Eric Mack
2 min read

An artist's impression of an exoplanet system around a red dwarf star.


Astronomers have zeroed in on a new up-and-coming candidate in the search for a planet beyond our solar system that might be able to sustain life.

Three so-called "super-Earths" have been spotted around the red dwarf star K2-155, around 200 light-years away. The outermost planet, K2-155d, is 1.6 times the size of Earth near the star's habitable zone and could be a watery planet, which is always a good sign when it comes to possibly harboring life.

Researchers ran what is known about the exoplanet through some climate modeling programs and found it has the potential to be habitable, especially if other factors like the absence of major solar flares from K2-155 turn out to also be positive. Fortunately for any hypothetical critters on K2-155d, no flares were seen from the star over a period of 80 days. We recently learned that the same can't be said for the nearest exoplanet, poor flare-blasted Proxima b

If there is life on K2-155d, it lives by very different natural cycles than Earth's. A year there would only be about 40 days long, but it would be tough to keep track of the days as the planet likely is tidally locked and doesn't spin on its axis, just like our moon. So any possible life forms there probably bask on the day-side of the planet in constant sunlight that has a more reddish hue than the yellow glare from our brighter sun.

The findings on K2-155d are based on data from the NASA Kepler spacecraft's second mission, K2, and follow-up observations from ground-based telescopes in Hawaii and Spain, among other places. They were published last month in the Astronomical Journal.

At this point, thousands of intriguing exoplanets have been identified, but the odds are good we'll hear more about K2-155d in the future because its host star is among the brightest of the red dwarf stars known to be orbited by planets.

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"Red dwarf systems, especially coolest red dwarfs, are just beginning to be investigated, so they are very exciting targets for future exoplanet research," Teruyuki Hirano, who led the research, said in a news release Monday. Hirano is with the Tokyo Institute of Technology.

Researchers like Hirano have been relying largely on data from Kepler to find exoplanet candidates, but we'll soon enter a new era of planet discovery with the planned launch of NASA's Transiting Exoplanet Survey Satellite (TESS) in April. 

"TESS is expected to find many candidate planets around bright stars closer to Earth," he says.

Soon, space fans may not only get excited by news of Elon Musk's plans for the red planet, but also by the search for life around red stars.

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