Astronomers using the SPHERE (Spectro-Polarimetric High-contrast Exoplanet Research) instrument on ESOs Very Large Telescope (VLT) have discovered a second planetary-mass companion orbiting TYC 8998-760-1, a 16.7-million-year-old solar-type star previously known to host one giant planet. The researchers have also managed to directly image this multi-planet system.
This image, captured by the SPHERE instrument on ESOs Very Large Telescope, shows TYC 8998-760-1 accompanied by two giant planets, TYC 8998-760-1b and TYC 8998-760-1c. The two planets are visible as two bright dots in the center (TYC 8998-760-1b) and bottom right (TYC 8998-760-1c) of the frame. Other bright dots, which are background stars, are visible in the image as well. Image credit: ESO / Bohn et al.
TYC 8998-760-1 is a K3-type star located 309 light-years away in the small southern constellation of Musca.
Also known as 2MASS J13251211-6456207, the star is about the same mass as our Sun, but is only 16.7 million years old.
The star was previously known to host a massive planet, TYC 8998-760-1b, with a radius of 3 times that of Jupiter and a mass of 14 Jovian masses.
The newly-discovered planet, TYC 8998-760-1c, is at least 6 times more massive than Jupiter.
The two alien worlds orbit their parent star at distances of 160 and 320 AU. This places these planets much further away from their star than Jupiter or Saturn are from the Sun.
This discovery is a snapshot of an environment that is very similar to our Solar System, but at a much earlier stage of its evolution, said Leiden University PhD student Alexander Bohn, lead author of the study.
Even though astronomers have indirectly detected thousands of planets in our galaxy, only a tiny fraction of these exoplanets have been directly imaged, added Leiden University astronomer Matthew Kenworthy, co-author of the study.
Direct observations are important in the search for environments that can support life.
TYC 8998-760-1 is the first directly imaged multi-planet system that is detected around a young analog of our Sun.
Our team has now been able to take the first image of two gas giant companions that are orbiting a young, solar analog, said co-author Dr. Maddalena Reggiani, a postdoctoral researcher at KU Leuven.
The study was published in the Astrophysical Journal Letters.
Alexander J. Bohn et al. 2020. Two Directly Imaged, Wide-orbit Giant Planets around the Young, Solar Analog TYC 8998-760-1. ApJL 898, L16; doi: 10.3847/2041-8213/aba27e