Planets around evolved binary systems

• Applicant: Professor Dr. Robi Stefan Banerjee
• Subject Area: Astrophysics and Astronomy
• Term: from 2018 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 400397976

From the more than 3000 observed white dwarf plus main-sequence (WDMS) systems, by now more than 200 post common envelope binaries (PCEBs) are known. Such post-common-envelope binaries (PCEBs) are not only exciting objects by themselves but could also harbour planets around them. To date, a handfull of PCEB systems have provided evidence for the presence of planets, despite their violent dynamical evolution. Currently, the most studied and hence most certain case is NN Ser, whose eclipse-timing variations can be explained by the presence of a planetary system consisting of two massive Jovian planets with roughly 7 and 2 MJup, orbiting their hosting binary at distances of 3 and 5 AU, respectively. Yet it is unclear how those planets are formed. In principle, such planets orbiting PCEBs can either form together with the binary, i.e. as first generation (FG) planets, or can be formed after the CE phase, as second generation (SG) planets. Here we will study both scenarios with three dimensional hydrodynamical simulations including N-body interaction.

• DFG Programme: Research Grants