Astronomers know of thousands of planets around other stars, yet only a handful have been imaged directly. The existence of the rest is inferred by how they affect their stars.
Now the world’s largest optical telescope has directly spied a new planetary system—the first time more than one planet has been imaged around a star like our Sun. Astronomers used the European Southern Observatory’s Very Large Telescope (VLT) to observe the Sun-like star TYC 8998-760-1, 300 light-years from Earth. Using the VLT’s Spectro-Polarimetric High-contrast Exoplanet Research (SPHERE) instrument, which is equipped with an optical mask called a coronagraph to block out a star’s light, they were able to see two planets orbiting it (pictured above), as reported today in The Astrophysical Journal Letters. Some light from the star can be seen in the image above (center left) as well as the two giant planets (right) and a scattering of background stars.
The snapshot will help astronomers learn how planetary systems evolve. TYC 8998-760-1, at only 17 million years, is a baby version of our 4.5-billion-year-old Sun, but their orbiting planets couldn’t be more different. The two newly discovered exoplanets are 14 and six times the mass of Jupiter, our heftiest planet, and orbit 16 and 32 times farther out than Saturn. If this system is going to evolve into something like ours over the next several billion years, astronomers have got some explaining to do.