Astronomers spot Jupiter-like hidden planet outside our Solar System

Astronomers, using the European Southern Observatory's Very Large Telescope (VLT) in Chile, have detected a Jupiter-like planet that orbits the star AF Leporis.

Planets orbit around their host stars and the gravitational pull they exert on the star causes the star to move slightly in response. As a result, the star's trajectory across the sky may be slightly altered from what it would be if there were no planets in its vicinity - an effect called perturbation which can be detected by observing the star's position over time.

Two independent groups of astronomers, led by Dino Mesa (INAF, Italy) and Robert De Rosa (ESO, Chile), found that AF Leporis exhibited such a disturbed trajectory, a telltale sign that a planet could be hiding there. They took a closer look at this system and managed to directly image the planet that orbits AF Leporis.

Using VLT's SPHERE instrument, which corrects the blurring caused by atmospheric turbulence using adaptive optics, and also blocks the light from the star with a special mask, the teams detected the planet next to it.

With a few times more massive than the gas giant Jupiter, the planet around AF Leporis is just the lightest exoplanet detected with the combined use of astrometric measurements and direct imaging.

1/ This Picture of the Week shows a Jupiter-like planet around the star AF Lep, imaged by two teams with our VLT. The planet's gravitational tug on the star had been detected with Hipparcos and @ESAGaia 🔗 https://t.co/roVYHsmNFt Credit: @ESO /Mesa, De Rosa et al. pic.twitter.com/KE5aAyZALT

— ESO (@ESO) February 20, 2023

According to ESO's post, the planet around the star AF Leporis, a star approximately the same size, mass, and temperature as our Sun, orbits it at a distance similar to that between Saturn and the Sun.

The AF Leporis system is about 200 times younger than the Sun and also has a debris belt with similar characteristics to the Kuiper belt in our Solar System.