Scientists from the Carnegie Institution for Science have discovered three massive planets in a binary star system with twin stars. Their findings are to be published in The Astronomical Journal.
The discovery was made possible by the Carnegie’s Planet Finder Spectrograph on the Magellan Clay Telescopes at Carnegie’s Las Campanas Observatory. The study took six years.
The stars are named HD 133131A and HD 133131B. HD 133131A hosts two planets, which measure one and a half times more massive than Jupiter and slightly more than half of Jupiter’s mass, respectively.
HD 133131B hosts a planet that measures 2.5 times Jupiter’s mass. The planets’ orbits are more elliptical than circular, the team adds.
The stars are 360 astronomical units (AU- distance between the Earth and sun). The stars are considered metal-poor due to their lack of iron or oxygen. Instead, most of the stars’ mass is composed of helium and hydrogen.
By comparison, most stars that host big planets are metal-rich. Hence, this newly found binary star system is just one of seven metal-poor binary star systems.
The stars are more like fraternal twin stars rather than identical twins, according to the research team. These two actually have different chemical compositions from one another.
The researchers say that this demonstrates that one of them swallowed young planets during its early life. These small planets were influenced by the gravitational forces of the giant ones, causing them to be pushed toward the star or outside their system.
This means that the giant planets could have influenced the solar system’s architecture.
“We are trying to figure out if giant planets like Jupiter often have long and/or eccentric orbits,” says lead researcher Johanna Teske. “If this is the case, it would be an important clue to figuring out the process by which our Solar System formed, and might help us understand where habitable planets are likely to be found.”