PORTO, Portugal — There appears to be a new planet in our midst.
A team of astronomers says they found evidence of a new planet orbiting Proxima Centauri, aka the star closest to the sun. The planet is said to be the lightest exoplanet ever found, weighing in at just a quarter of the Earth's mass.
Their findings, published Feb. 10 in the journal "Astronomy & Astrophysics," reports the candidate planet is the third detected to be orbiting the star.
“The discovery shows that our closest stellar neighbor seems to be packed with interesting new worlds, within reach of further study and future exploration,” the study's lead author and researcher at the Institute of Astrophysics and Space Sciences, João Faria said.
The planet named Proxima d orbits the star at a distance of nearly 2.5 million miles. It's joined by Proxima b, which is reported to be comparable in mass to the Earth and orbits the star every 11 days and Proxima c which orbits the star every five years.
Researchers say Proxima d has the shortest orbit around the star. According to the study, the planet takes just five days to orbit between Proxima Centauri and "the habitable zone"
The first hints of Proxima d's existence surfaced in 2020 when astronomers say they spotted a signal corresponding with what turned out to be the planet.
“After obtaining new observations, we were able to confirm this signal as a new planet candidate,” Faria said. “I was excited by the challenge of detecting such a small signal and, by doing so, discovering an exoplanet so close to Earth.”
Given its small size, astronomers say Proxima d's gravity has little impact on the star. It's reported Proxima Centauri only moves back and forth around 40 centimeters per second.
“This achievement is extremely important,” said Pedro Figueira, ESPRESSO instrument scientist at the European Southern Observatory in Chile.“It shows that the radial velocity technique has the potential to unveil a population of light planets, like our own, that are expected to be the most abundant in our galaxy and that can potentially host life as we know it.”