Planets with two suns exist in fiction. Example with Tatooine: Luke Skywalker’s parent planet in the saga star Wars. In fact, these types of planets can exist – called circular ones, which orbit around two stars. At least, the theory didn’t rule it out. But we didn’t notice anything… until about ten years ago, when the Kepler space telescope began discovering them. Since then, dozens of people have been identified, always from space. For the first time, such a planet was discovered from Earth. The results of this observation are detailed in an article published this year in Monthly Notices of the Royal Astronomical Society. Its name: Kepler-16b. were known. It was even the first of its kind discovered by Kepler in 2011.” The interest here was to test our observational method to demonstrate that we were able to detect an exoplanet in such a two-star system from Earth, explains Isabelle Boys, an astronomer at the Marseille Astrophysics Laboratory (LAM) and co-author of the study. We can now envision discovering so many of them in this much less expensive way than space telescopes. »
Two hundred systems to explore
The method in question used the Sophie instrument: a spectrometer installed at the Haute-Provence Observatory which makes it possible to detect exoplanets using radial velocities. By smashing the incoming light from the stars, it is possible to observe the disturbances in their movement caused by the presence of a planet around them. ” This method can detect more exoplanets than the transit method “, notes Alexander Santern, an astrophysicist at LAM who was also involved in the study. The transit method, used by Kepler, makes it possible to detect an exoplanet when it passes in front of its star and reduces the amount of light received on Earth.” The orbit of an exoplanet must allow it to pass exactly between its star and Earth Alexandre Santern says.
Using their new tool, astronomers set out to discover these other worlds. ” A similar initial view from the southern hemisphere is expected to be published soon. “Slips Isabelle Boisse. Because to cover the entire sky and observe the invisible part of the northern hemisphere, an observatory was called in Chile with the choral, harps and espresso spectrometers. In the coming years program: Observe about 200 two star systems in the hope of discovering new planets in orbit. It is no longer a question of confirming their existence or testing a method, but of discovering as many circular exoplanets as possible.