Very Large Telescope finds hidden exoplanet in unique stellar system
The European Southern Observatory's (ESO) Very Large Telescope in Chile has helped discover an exoplanet in a unique stellar system called HIP 81208. Until now, this system, which is located about 480 light-years away from Earth, was known to contain a central massive star, a brown dwarf, and another low-mass star orbiting further away. The new planet in this system came to light when astronomers were reanalyzing pictures snapped by the Very Large Telescope, one of the world's largest telescopes.
The exoplanet is 15 times more massive than the Sun
The newly discovered exoplanet is approximately 15 times more massive than Jupiter. It orbits the smaller star in the HIP 81208 system that itself orbits the larger star. Also, the brown dwarf—an astronomical object that is intermediate between a planet and a star—is orbiting around the larger star. This arrangement, "with two stars and two smaller bodies orbiting each one," is called a hierarchical quadruple system, and will help astronomers further their understanding of complex systems, like HIP 81208.
First 'hierarchical quadruple system' to be found using direct imaging
In addition, the discovery of the exoplanet in HIP 81208 marks the "first hierarchical quadruple system to be found using direct imaging," according to ESO. Most exoplanets are discovered through what's called the transit method, which involves observing fluctuations in a star's brightness caused by a planet passing in front of its disk. This makes the latest discovery particularly noteworthy.
Direct imaging technique reveals hidden exoplanet
Unlike the transit method, direct imaging can be compared to traditional photography. As the name suggests, the technique involves observing exoplanets directly. In the reanalyzed images, astronomers from the Paris Observatory found that the giant exoplanet was creating a blob in the ring of light surrounding its parent star. Considering the mass of the new planet, it almost can be classified as a brown dwarf itself.
