Several planets found orbiting star less than 6 light-years away
Astronomers have confirmed the existence of four planets orbiting a star less than 6 light-years away with help from some of the world's most powerful telescopes.
Research published in October 2024 revealed that one planet was rotating around Barnard's Star, the second-closest single star system to Earth. But a combination of telescopes all over the world confirmed the presence of four small exoplanets, according to a study published last week in The Astrophysical Journal Letters.
The Gemini Telescope in Hawaii and the Very Large Telescope in Chile were used to detect the additional rocky planets, the astronomers said.
"It's signaling a breakthrough with the precision of these new instruments from previous generations," said Ritvik Basant, Ph.D student at the University of Chicago and lead author of the paper, in a statement.
The first planet was detected using a 27-foot diameter telescope at the European Space Observatory’s Paranal Observatory in Chile and a spectrograph that could quickly detect changes in the star's velocity, according to the 2024 paper, published in the journal Astronomy & Astrophysics.
Barnard's Star, a low-mass red dwarf, was discovered in 1916. Since then, astronomers have discovered that at least 70% of all stars in the Milky Way are this type of star, which is why researchers want to know about the types of planets that orbit them, according to the University of Chicago.
"It's a really exciting find -- Barnard's Star is our cosmic neighbor, and yet we know so little about it," Basant said.
The planets are 20% to 30% the mass of Earth and make a full orbit around the sun in days, according to the paper. They are likely rocky planets, rather than gas.
Since they are so close to Barnard's Star, they are likely too hot to sustain life. The researchers ruled out the existence of other planets within the habitable zone of Barnard's Star.
The planets are difficult to detect because their stars shine so brightly next to them, the researchers said.
Scientists from the Gemini Observatory, National Science Foundation NOIRLab, Heidelberg University and the University of Amsterdam calibrated and analyzed data taken during 112 different nights over three years, where they found "solid evidence" to the existence of the additional planets orbiting Barnard's Star, according to the paper.
"We observed at different times of night on different days," Basant said. "They're in Chile; we're in Hawaii. Our teams didn't coordinate with each other at all."
He added, "That gives us a lot of assurance that these aren't phantoms in the data."
