La Jornada: They reveal the existence of an atmosphere on a rocky planet

Madrid. Almost a decade after the discovery of LHS 1140b, a rocky exoplanet in the habitable zone of a nearby low-mass star, a new study reveals that the object could have its own atmosphere, according to experts at the University of Florida (United States).

Specifically, Jason Dittmann, PhD in astronomy and associate professor at the University of Florida, discovered the planet for the first time in 2016. Now, he is co-author of this new study, published in Sciencewhich uses helium escape to explain a possible atmosphere.

“The most interesting thing about this article is that it is the first time we see a rocky planet, similar to Earth, that could still have an atmosphere,” he details.

The telescope Magellan Clay from the Las Campanas Observatory in Chile showed evidence that helium is escaping the planet. However, the planet’s age indicates that it would have run out of helium unless it was replenishing its own reserves, pointing to the possible existence of an atmosphere.

In 2016, Dittmann used ground-based surveys to look for stars whose light dimmed briefly when orbiting planets passed in front of them.

Similar to Earth

However, ground-based observation allows the Earth’s atmosphere to interfere with this process. To understand whether the stars’ brightness was due to wispy clouds or moisture blowing in from Earth, he trained a machine learning algorithm to decipher which signals were caused by Earth’s climate and which by the passage of a planet.

This method helped Dittmann find LHS 1140b. Due to the planet’s orbit, it could only be observed a few times a year, so he tried to take advantage of the limited opportunities he had to study it.

Considering the type of star it orbits around, Dittmann stated that the planet’s temperature should be similar to that of Earth. It is made of rock rather than gas and is located about 40 light years away. There is also a second planet in the system, LHS 1140c, which is located outside the system’s habitable zone.