Using ESO's Very Large Telescope, astronomers have directly imaged a giant planet orbiting a massive binary star system visible to the naked eye with an ultra-hot primary star. This discovery challenges long-held assumptions that planets cannot form around such extreme environments.
Located about 325 light-years away in the constellation Centaurus, the binary star system b Centauri (also known as HIP 71865) has a combined mass of roughly six times that of the Sun. Like many massive stars, its primary is a B-type star, three times hotter than our Sun, emitting intense ultraviolet radiation and X-rays.
These extreme conditions—heavy mass and scorching heat—disrupt surrounding gas clouds so severely that planet formation was previously considered impossible. Yet, a study published in Nature provides compelling evidence to the contrary.
Observations with ESO's Very Large Telescope revealed a planet at least ten times more massive than Jupiter, orbiting at nearly 100 times the Earth-Sun distance—farther than any known exoplanet around such a massive host.
No planets had been confirmed around stars exceeding three solar masses until now. This breakthrough demonstrates that planets can form even in these harsh stellar environments.
“This planet inhabits an alien world utterly unlike Earth or our Solar System,” says Gayathri Viswanath, University of Stockholm researcher and co-author. “It's a brutal realm of extreme radiation, where everything is supersized: the stars, the planet, and the orbits.”
The VLT's advanced capabilities enabled the first clear image of this planet, shown below.
Captured using the Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE) instrument on ESO's VLT in Chile, this world was actually photographed over 20 years ago by another telescope—but unrecognized as a planet at the time.
Future observations with ESO's Extremely Large Telescope, set to begin in 2025, along with VLT upgrades, promise deeper insights into this extraordinary planet's formation and properties.
