Rare exoplanet discovered in Milky Way’s outer halo, researchers say

By Asiye Latife Yilmaz

ISTANBUL (AA) - Astronomers have discovered a rare gas giant exoplanet in the outermost regions of the Milky Way, making it the third known find of its kind in history.

Researchers from Vilnius University in Lithuania, collaborating with international partners, made the discovery using gravitational microlensing, a phenomenon first predicted by Albert Einstein in the early 1900s.

“This is only the third planet ever discovered so far from the Galactic bulge,” said Edita Stonkute, a professor on the research team, in a report published on Lithuania’s official website on Wednesday.

The planet named AT2021uey b was detected 3,262 light-years away in the galactic halo, far from the dense central regions where most exoplanets have been found.

Gravitational microlensing occurs when a massive object passes in front of a distant star, bending its light and causing a brief brightening that astronomers use to detect planets.

“This kind of research demands a great deal of expertise, patience—and, frankly, a bit of luck,” said Marius Maskoliunas, head of the Lithuanian research team.

The exoplanet, estimated to be 1.3 times the mass of Jupiter, orbits an M dwarf star every 4,170 days.

The team said the planet’s large size made detection easier, while smaller, Earth-like planets remain much more difficult to find.

“When that first discovery was made, it was a shock to find a Jupiter-sized planet so close to its star,” Stonkute said.

“As more data came in, we realized that many planetary systems look nothing like our solar system. We’ve had to rethink our models of how planets form,” she added.