About the Newfound Rocky World
A newly discovered extraterrestrial world could throw light on one of the exoplanet family tree’s darkest and oddest sections.
The planet, dubbed GJ 367b, orbits a small, dim red dwarf star approximately 31 light-years from the sun, according to its discoverers.
According to study team members, GJ 367b is a rocky world that is 70 percent the size of Earth and 55 percent the mass, making it one of the lightest known exoplanets. It is classified as an “ultra-short period” (USP) planet because it completes one orbit in 7.7 hours, a mysterious and understudied class of the world.
“We already know a few of these, but their origins are still unclear,” says Kristine W. F. Lam of the German Aerospace Center’s Institute of Planetary Research.
“We can gain a peek of the system’s creation and evolution history by examining the precise fundamental features of the USP planet,” says Lam.
Distinguishing an Extreme World
GJ 367b was found by Lam, Szilárd Csizmadia, who also belongs to the DLR’s Institute of Planetary Research, along with their colleagues. They used data from NASA’s Transiting Exoplanet Survey Satellite (TESS), which was sent into orbit around Earth in April 2018.
TESS uses the “transit method” to look for planets, detecting the small brightness dips that occur when a planet crosses its star’s face from the spacecraft’s perspective. TESS observations of the red dwarf GJ 367 revealed such a dip, which was discovered by the finding team. Its diameter is around half that of our sun, and it was later established that the signal was created by a transiting planet.
The HARPS observations revealed how much GJ 367b was dragging on its host star, allowing the researchers to compute the exoplanet’s mass. The researchers were able to establish GJ 367b’s density, which is higher than that of Earth, by combining the multiple measurements.
In a DLR release, Csizmadia remarked, “The high density indicates the planet is dominated by an iron core.” “These features are similar to those of Mercury, which is distinguished from other terrestrial worlds in the solar system by its abnormally huge iron and nickel core.”
GJ 367b is a poor prospect for sustaining life as we know it. The planet is bombarded by stellar radiation due to its proximity to its host star. According to study team members, it absorbs nearly 500 times the amount of sunlight that Earth receives.
GJ 376b’s formation is unknown, but Lam believes that a few potential scenarios could explain its shape and composition. GJ 376b could perhaps be the remnant of a bigger planet that lost a lot of mass due to stellar radiation or a massive impact.
“If the planet is a remnant core of a past gaseous planet, the gaseous planet should be little larger than a Neptune-sized planet,” Lam said in an email to Space.com.