Hunting for planets with double sunsets: the case of HW Vir

Friday, September 21, 2018 - 14:00
Dipartimento di Fisica
Dr. Samantha Beatriz Brown Sevilla
Dipartimento di Astronomia dell'Università di Padova

The timing variations technique was the method used to detect the first extrasolar planets back in 1992. Since then, there have been more than 3,700 exoplanets discovered, most of them orbiting Sun-like stars, however, there is an increasing number of them being discovered orbiting all kinds of stars. Among them, one of the most interesting cases is the one of circumbinary planets, which orbit two stars instead of one. These kind of planets can be detected, among other techniques, via the periodic variations of stellar eclipses in eclipsing binary stars. Considering that ~50% of the stars we observe are binaries, studying the presence of planets around these kind of systems could teach us a lot about an important number of exoplanets and their fates. An interesting example of these systems is the eclipsing pair HW Virginis, which was the first-ever discovered binary system composed by a sub-dwarf (sdB) and a main sequence M star (dM). This system has been studied due to its period variations in the past, however, a conclusive explanation for them is still missing in the literature. In this talk I will describe the data I used to study HW Vir as well as our findings regarding its period variations.

 

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