Search Publications
Six transiting planets and a chain of Laplace resonances in TOI-178
Alonso, R.; Bouchy, F.; Deleuil, M. +152 more
Determining the architecture of multi-planetary systems is one of the cornerstones of understanding planet formation and evolution. Resonant systems are especially important as the fragility of their orbital configuration ensures that no significant scattering or collisional event has taken place since the earliest formation phase when the parent …
CHEOPS observations of the HD 108236 planetary system: a fifth planet, improved ephemerides, and planetary radii
Guterman, P.; Alonso, R.; Deleuil, M. +106 more
Context. The detection of a super-Earth and three mini-Neptunes transiting the bright (V = 9.2 mag) star HD 108236 (also known as TOI-1233) was recently reported on the basis of TESS and ground-based light curves.
Aims: We perform a first characterisation of the HD 108236 planetary system through high-precision CHEOPS photometry and improve t…
The changing face of AU Mic b: stellar spots, spin-orbit commensurability, and transit timing variations as seen by CHEOPS and TESS
Guterman, P.; Alonso, R.; Deleuil, M. +78 more
AU Mic is a young planetary system with a resolved debris disc showing signs of planet formation and two transiting warm Neptunes near mean-motion resonances. Here we analyse three transits of AU Mic b observed with the CHaracterising ExOPlanet Satellite (CHEOPS), supplemented with sector 1 and 27 Transiting Exoplanet Survey Satellite (TESS) photo…
CHEOPS precision phase curve of the Super-Earth 55 Cancri e
Guterman, P.; Alonso, R.; Deleuil, M. +79 more
Context. 55 Cnc e is a transiting super-Earth (radius 1.88 R⊕ and mass 8 M⊕) orbiting a G8V host star on a 17-h orbit. Spitzer observations of the planet's phase curve at 4.5 µm revealed a time-varying occultation depth, and MOST optical observations are consistent with a time-varying phase curve amplitude and phase off…
A search for transiting planets around hot subdwarfs. I. Methods and performance tests on light curves from Kepler, K2, TESS, and CHEOPS
Alonso, R.; Deleuil, M.; Erikson, A. +79 more
Context. Hot subdwarfs experienced strong mass loss on the red giant branch (RGB) and are now hot and small He-burning objects. These stars constitute excellent opportunities for addressing the question of the evolution of exoplanetary systems directly after the RGB phase of evolution.
Aims: In this project we aim to perform a transit survey …
A CHEOPS white dwarf transit search
Lendl, Monika; Brandeker, Alexis; Heng, Kevin +2 more
White dwarf spectroscopy shows that nearly half of white dwarf atmospheres contain metals that must have been accreted from planetary material that survived the red giant phases of stellar evolution. We can use metal pollution in white dwarf atmospheres as flags, signalling recent accretion, in order to prioritize an efficient sample of white dwar…
Constraining stellar rotation and planetary atmospheric evolution of a dozen systems hosting sub-Neptunes and super-Earths
Fossati, L.; Kubyshkina, D.; Bonfanti, A. +1 more
Context. Planetary atmospheric evolution modelling is a prime tool for understanding the observed exoplanet population and constraining formation and migration mechanisms, but it can also be used to study the evolution of the activity level of planet hosts.
Aims: We constrain the planetary atmospheric mass fraction at the time of the dispersa…