Search Publications
Analysis of Early Science observations with the CHaracterising ExOPlanets Satellite (CHEOPS) using PYCHEOPS
Guterman, P.; Alonso, R.; Deleuil, M. +77 more
CHEOPS (CHaracterising ExOPlanet Satellite) is an ESA S-class mission that observes bright stars at high cadence from low-Earth orbit. The main aim of the mission is to characterize exoplanets that transit nearby stars using ultrahigh precision photometry. Here, we report the analysis of transits observed by CHEOPS during its Early Science observi…
A pair of sub-Neptunes transiting the bright K-dwarf TOI-1064 characterized with CHEOPS
Lester, Kathryn V.; Charnoz, Sébastien; Triaud, Amaury H. M. J. +132 more
We report the discovery and characterization of a pair of sub-Neptunes transiting the bright K-dwarf TOI-1064 (TIC 79748331), initially detected in the Transiting Exoplanet Survey Satellite (TESS) photometry. To characterize the system, we performed and retrieved the CHaracterising ExOPlanets Satellite (CHEOPS), TESS, and ground-based photometry, …
The atmosphere and architecture of WASP-189 b probed by its CHEOPS phase curve
Alonso, R.; Deleuil, M.; Erikson, A. +83 more
Context. Gas giants orbiting close to hot and massive early-type stars can reach dayside temperatures that are comparable to those of the coldest stars. These `ultra-hot Jupiters' have atmospheres made of ions and atomic species from molecular dissociation and feature strong day-to-night temperature gradients. Photometric observations at different…
Spi-OPS: Spitzer and CHEOPS confirm the near-polar orbit of MASCARA-1 b and reveal a hint of dayside reflection
Alonso, R.; Deleuil, M.; Erikson, A. +82 more
Context. The light curves of tidally locked hot Jupiters transiting fast-rotating, early-type stars are a rich source of information about both the planet and star, with full-phase coverage enabling a detailed atmospheric characterisation of the planet. Although it is possible to determine the true spin-orbit angle Ψ - a notoriously difficult para…
Detection of the tidal deformation of WASP-103b at 3 σ with CHEOPS
Alonso, R.; Bouchy, F.; Deleuil, M. +80 more
Context. Ultra-short period planets undergo strong tidal interactions with their host star which lead to planet deformation and orbital tidal decay.
Aims: WASP-103b is the exoplanet with the highest expected deformation signature in its transit light curve and one of the shortest expected spiral-in times. Measuring the tidal deformation of th…
A detailed analysis of the Gl 486 planetary system
Amado, P. J.; Caballero, J. A.; Pallé, E. +64 more
Context. The Gl 486 system consists of a very nearby, relatively bright, weakly active M3.5 V star at just 8 pc with a warm transiting rocky planet of about 1.3 R⊕ and 3.0 M⊕. It is ideal for both transmission and emission spectroscopy and for testing interior models of telluric planets.
Aims: To prepare for future studi…
Investigating the architecture and internal structure of the TOI-561 system planets with CHEOPS, HARPS-N, and TESS
Guterman, P.; Alonso, R.; Deleuil, M. +115 more
We present a precise characterization of the TOI-561 planetary system obtained by combining previously published data with TESS and CHEOPS photometry, and a new set of 62 HARPS-N radial velocities (RVs). Our joint analysis confirms the presence of four transiting planets, namely TOI-561 b (P = 0.45 d, R = 1.42 R⊕, M = 2.0 M⊕)…
Uncovering the true periods of the young sub-Neptunes orbiting TOI-2076
Alonso, R.; Bouchy, F.; Deleuil, M. +93 more
Context. TOI-2076 is a transiting three-planet system of sub-Neptunes orbiting a bright (G = 8.9 mag), young (340 ± 80 Myr) K-type star. Although a validated planetary system, the orbits of the two outer planets were unconstrained as only two non-consecutive transits were seen in TESS photometry. This left 11 and 7 possible period aliases for each…
CHEOPS geometric albedo of the hot Jupiter HD 209458 b
Guterman, P.; Alonso, R.; Deleuil, M. +74 more
We report the detection of the secondary eclipse of the hot Jupiter HD 209458 b in optical/visible light using the CHEOPS space telescope. Our measurement of 20.4−3.3+3.2 parts per million translates into a geometric albedo of Ag = 0.096 ± 0.016. The previously estimated dayside temperature of about 1500 K implies …
Stellar limb darkening. A new MPS-ATLAS library for Kepler, TESS, CHEOPS, and PLATO passbands
Solanki, S. K.; Shapiro, A. I.; Maxted, P. F. L. +4 more
Context. The detection of the first exoplanet paved the way for the era of transit-photometry space missions with revolutionary photometric precision, whose aim is to discover new exoplanetary systems around different types of stars. With this high precision, it is possible to derive the radii of exoplanets very accurately, which is crucial for co…