Search Publications
The CHEOPS mission
Guterman, P.; Alonso, R.; Deleuil, M. +107 more
The CHaracterising ExOPlanet Satellite (CHEOPS) was selected on October 19, 2012, as the first small mission (S-mission) in the ESA Science Programme and successfully launched on December 18, 2019, as a secondary passenger on a Soyuz-Fregat rocket from Kourou, French Guiana. CHEOPS is a partnership between ESA and Switzerland with important contri…
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 …
Transit detection of the long-period volatile-rich super-Earth ν2 Lupi d with CHEOPS
Charnoz, Sébastien; Guedel, Manuel; Gandolfi, Davide +75 more
Exoplanets transiting bright nearby stars are key objects for advancing our knowledge of planetary formation and evolution. The wealth of photons from the host star gives detailed access to the atmospheric, interior and orbital properties of the planetary companions. ν2 Lupi (HD 136352) is a naked-eye (V = 5.78) Sun-like star that was d…
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…
TIC 172900988: A Transiting Circumbinary Planet Detected in One Sector of TESS Data
Kostov, Veselin B.; Powell, Brian P.; Torres, Guillermo +85 more
We report the first discovery of a transiting circumbinary planet detected from a single sector of Transiting Exoplanet Survey Satellite (TESS) data. During Sector 21, the planet TIC 172900988b transited the primary star and then five days later it transited the secondary star. The binary is itself eclipsing, with a period P ≈ 19.7 days and an ecc…
Exploiting timing capabilities of the CHEOPS mission with warm-Jupiter planets
Alonso, R.; Deleuil, M.; Erikson, A. +75 more
We present 17 transit light curves of seven known warm-Jupiters observed with the CHaracterising ExOPlanet Satellite (CHEOPS). The light curves have been collected as part of the CHEOPS Guaranteed Time Observation (GTO) program that searches for transit-timing variation (TTV) of warm-Jupiters induced by a possible external perturber to shed light …
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 …
The EBLM project - VIII. First results for M-dwarf mass, radius, and effective temperature measurements using CHEOPS light curves
Guterman, P.; Alonso, R.; Deleuil, M. +93 more
The accuracy of theoretical mass, radius, and effective temperature values for M-dwarf stars is an active topic of debate. Differences between observed and theoretical values have raised the possibility that current theoretical stellar structure and evolution models are inaccurate towards the low-mass end of the main sequence. To explore this issu…