Description
Half of the stars in the Milky Way are in binary systems. In recent years, many planets have been found either in circumbinary configurations or around a star in a very tight binary. The existence of these planets, at the limit of stability, is very intriguing and their understanding can place many constraints on the formation process.
I will review the detection methods and properties of observed exoplanets in binary star systems and how those are helpful to tease out certain physical processes during planet formation.
The number of planets orbiting binary stars is increasing dramatically thanks to TESS and follow-up by direct imaging/Gaia. Understanding the origin and orbital architecture of these systems requires end-to-end planet formation models, which do not exist yet for planets orbiting only one of the two stars (S-type binaries). In this talk, I will introduce a new global planet formation model for...
In stellar multiple systems, orbits on the scale of ~10 to 100 au appear to suppress planet occurrence. However, some planetary systems do form and survive in close binaries, and the reasons why provide clues to important factors in successful planet formation. The Kepler sample remains the preeminent source of planetary demographics and, crucially, is also agnostic to stellar multiplicity. I...
It has long been argued that the occurrence rate of circumbinary planets (CBPs) should be comparable to that of planets around single stars (~10%). Yet, despite the favorable geometry of eclipsing binaries for transit detection and the modeled efficiency of planet formation in circumbinary natal disks, a set of only 14 transiting CBPs have been identified to date by Kepler and TESS, suggesting...
Of the 14 transiting planets that have been detected orbiting eclipsing binaries ('circumbinary planets'), none have been detected with stellar binary orbital periods shorter than 7 days, despite such binaries existing in abundance. The eccentricity-period data for stellar binaries indicates that short-period (< 7 day) binaries have had their orbits tidally circularized. We examine here to...
Of the thousands of known exoplanets, only fifteen are circumbinary, oribiting two stars instead of one. All of these systems have been detected via transit photometry, which requires a low mutual inclination for all three objects to eclipse. However, over a long time baseline a wide planetary-mass companion to a binary system will induce orbital precession, modulating the relative eclipse...
Of the types of planets orbiting binary stars, one particularly interesting category is planets with a very large mutual inclination with the inner binary, on a "polar" orbit. While polar circumbinary planets have eluded detection so far, highly misaligned and polar circumbinary gas and debris discs have been observed. Should these discs form planets it can be assumed that the corresponding...
Stellar multiplicity plays a crucial role in shaping planetary system architectures. While the influence of stellar companions has been widely explored in binary systems, planets in hierarchical triple systems remain largely underexplored. The complex gravitational interplay within these systems challenges planet formation models, influencing migration, altering orbital eccentricities, and...
In this work we present the latest developments in the problem of the stability of circumbinary planets and how to identify stable and unstable orbits in such systems. In this context, we carry out more than 3x10^8 numerical simulations of planets between the size of Mercury and the lower fusion boundary (13 Jupiter masses) which revolve around the center of mass of a stellar binary over long...
Numerical simulations of circum-stellar planetary orbits in binary star systems show that the eccentricity of such planets can vary due to the gravitational interaction with the secondary star. The evolution of the eccentricity depends on the architecture of the binary star-planet system. We have developed methods to localize these gravitational perturbations which display It is shown that...
An anomalous population of planets has recently been discovered in the previously barren Neptunian Desert. To understand these unusual planets it is important to recognise system and planetary properties that the Desert shares with more populous and well-studied types of exoplanets. In this work, we aim to discover whether a high stellar multiplicity rate is another of these features, shared...
