Part of the new image, showing the star (upper left) and giant exoplanet.Image: ESO/Bohn et al.
This first-of-its-kind image reveals a star system just 300 light-years from Earth. It was captured by the Very Large Telescope (VLT), which is managed by the European Southern Observatory and located in the Atacama desert of Chile. This is considered the first direct image of multiple exoplanets in orbit around a star similar to our own, according to an ESO press release.
“Even though astronomers have indirectly detected thousands of planets in our galaxy, only a tiny fraction of these exoplanets have been directly imaged,” said Leiden University astronomer Matthew Kenworthy, a co-author of a new paper, published to The Astrophysical Journal Letters, describing this planetary system, in the press release.
The star TYC 8998-760-1 accompanied by two giant exoplanets.Image: ESO/Bohn et al.
The Spectro-Polarimetric High-contrast Exoplanet REsearch instrument (SPHERE) on VLT made this image possible. Like a hand blocking the Sun, SPHERE used a device called a coronagraph to remove unwanted light from the host star, allowing the astronomers to see the fainter objects nearby.
This planetary system is quite young. At an estimated 17 million years old, the host star, called TYC 8998-760-1, is just a baby, compared to our middle-aged Sun, which is some 4.6 billion years old.
Another distinctive feature of this system is that the exoplanets, both of which are massive gas giants, are considerably farther from their host star compared to our gas giants, Jupiter and Saturn. The farther exoplanet is 320 AU (a unit of measurement in which 1 AU is the distance from Earth to the Sun) from its star, while the other is at 160 AU. By comparison, Jupiter and Saturn are 5 and 10 AU from the Sun, respectively.
These gas giants are also quite large, even for giants. The inner exoplanet is 14 times the mass of Jupiter, while the outer object is six times the mass of Jupiter.
Looking ahead, astronomers would like to study these planets further and determine how and where they originally formed. A big question in astronomy is whether large planets such as these form close to their host stars and steadily migrate outwards or if some other planetary migration scenarios exist. This system is young and relatively close, making it an ideal candidate for this sort of investigation.