Detection and Characterization of Exoplanets

Collaboration: Gael Chauvin, Patricio Rojo, Laura Perez, James Jenkins, Sebastian Jorquera, Pantoja Blake, Amelia Bayo, Johan Olofsson, Nicolas Godoy, Virginie Faramaz, Alice Zurlo, Hervé Beust, Mickael Bonnefoy, Philippe Delorme, Anne-Marie Lagrange, David Mouillet, Arthur Vigan and Nuria Huélamo.

The study of the early phases of planetary formation: The goal is to provide theoreticians with direct observables of accretion-markers in young exoplanets to test if giant planets share similar accretion processes with stars and brown dwarfs. This can be connected with the disk properties, morphology and chemistry explored thanks to the combination of multi-wavelengths high-angular resolution instruments (NaCo, SPHERE, ALMA, MATISSE, ERIS). The disk asymmetries (cavity, gap, hole, clump, vortex…) can also constrain the presence and properties of planetary perturbers. Two observing programs dedicated to the search of young accreting proto-planets in transition disks with NaCo in thermal imaging (PI: L. Pérez) and SPHERE using ZIMPOL in Hα imaging (PI: Huélamo) are currently on-going.

Exoplanetary Atmospheres of Young, Cool Exoplanets: The past two decades have been critical to improve our vision and knowledge of cool sub-stellar atmospheres with the extension of the standard classification of stars (MK system) to the so-called “L”, “T” and “Y” spectral types, now commonly used in Astronomy for low-mass stars, brown dwarfs and giant exoplanets. Today, most imaged exoplanets are young, late-M or L-type, massive planets with dusty atmospheres. In this context, we have initiated with the X-SHYNE (X-SHooter medium-resolution near-infrared survey for Young, Nearby Exoplanet analogs; 70hrs over periods P101, P102, P103 and P104) program aimed at characterizing, at medium resolution, the near-infrared spectral energy distribution of thirty young brown dwarf analogs to exoplanets, recently identified in young, nearby associations. This population of early-L to L/T-type isolated planetary-mass objects, with known distances and ages, offers ideal laboratory to explore the physical processes at play in comparable atmospheres to the ones of known imaged exoplanets.

Exploring Extreme Planetary Architectures: A final project is finally devoted to the characterization of extreme planetary systems in the configuration of close binaries that offer an ideal laboratory to test predictions of planetary formation theories in extreme conditions. In this context, a VLTI/GRAVITY, VLT/SPHERE and SOAR program (PI: Chauvin and Mendez) in coordination with Direct Imaging and Radial Velocity programs aimed at exploiting the dual-field capability of Gravity to resolve the astrometric wobbling owing to Hot Jupiters in tight binaries to derive the planet’s dynamical mass and to resolve the mutual inclination of the binary and planetary orbits. This will help understand how this planetary system formed and survived in such an extreme dynamical configuration.