For the first time, an exoplanet family around a sunlike star has had its portrait taken. Astronomers used the Very Large Telescope in Chile to snap a photo of two giant planets orbiting a young star with about the same mass as the sun, researchers report July 22 in The Astrophysical Journal Letters.
The star, called TYC 8998-760-1, is about 300 light-years away in the constellation Musca. At just 17 million years old, the planetary family is a youngster compared with the 4-billion-year-old solar system.
Although astronomers have found thousands of exoplanets, most aren’t observed directly. Instead they are spotted as shadows crossing in front of their stars, or inferred as unseen forces tugging at their stars.
Only a few tens of planets have been photographed around other stars, and just two of those stars have more than one planet. Neither is sunlike, says astronomer Alexander Bohn of Leiden University in the Netherlands — one is more massive than the sun, the other less massive.
Both of this star’s planets are unlike anything seen in the solar system. The inner planet, a giant weighing 14 times the mass of Jupiter, is 160 times farther from its star than Earth is from the sun. The outer one weighs six times Jupiter’s mass and orbits at twice its sibling’s distance. In comparison, the Voyager 1 spacecraft, which flew past the boundary marking the sun’s magnetic influence and into interstellar space in 2012, is still closer to the sun than either planet is to its star (SN: 9/12/13).
This exoplanet family could provide new insight into how solar systems can form. “As with many other exoplanet discoveries, this discovery makes us aware of other scenarios that we did not think of,” Bohn says.