Science Writing, (EFE).- So far only one was known, but now astronomers have reported the discovery of a new system made up of two stars and two planets that orbit around both.
These formations are known as circumbinary systems, and the best-known planet of this type is actually in the realm of science fiction. It is called Tatooine and it was the home of Luke and Anakin Skywalker in the “Star Wars” saga.
The discovery is published today in Nature Astronomy in a study coordinated by the University of Birmingham (UK), which has used an ancient technique to locate the new body orbiting the two stars.
multiple star systems
Circumbinary planets used to be relegated solely to science fiction, but thanks to data collected by NASA’s Kepler mission, astronomers now know that multiple star systems are more common than previously thought, says the State University of Ohio (USA), who also participated in the study.
This two-star system is called TOI-1338/BEBOP-1 and in 2020 its first planet (TOI-1338b) was located, the discovery of a second makes it the second known binary star system that hosts multiple planets.
65 times larger than Earth
The new planet, classified as BEBOP-1c, is a large gas giant, which has an orbital period around the two stars of 215 days and a mass 65 times greater than Earth, although its exact size has not yet been determined.
Scientists understand very little about the planets that form around multiple star systems.
Finding these planets “can be a bit trickier”
When a planet orbits two stars, “it can be a little trickier to find because its two stars are also moving through space,” explains David Martin, co-author of the study from The Ohio State University.
The way in which the exoplanets of these stars can be detected and the way in which they form “are quite different” and the most widely used method is that of transit, which makes it possible to indirectly detect a planet by measuring the decrease in brightness of light when a planet crosses between a star and an observer on Earth.
Observations made with the method of radial velocities
However, in this study, the researchers used only observations made with the radial velocities method, which is based on measuring the gravitational displacements that planets exert on their host stars over time.
This is the same method used to find the 1995 exoplanet, now known as Dimidium.
The discovery, according to the team, could also help scientists looking for life on other planets, as the inner planet already found in this binary system would be a prime candidate for atmospheric study by the James Webb Space Telescope.