Search Publications
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…
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…
Phase curve and geometric albedo of WASP-43b measured with CHEOPS, TESS, and HST WFC3/UVIS
Alonso, R.; Deleuil, M.; Erikson, A. +79 more
Context. Observations of the phase curves and secondary eclipses of extrasolar planets provide a window onto the composition and thermal structure of the planetary atmospheres. For example, the photometric observations of secondary eclipses lead to the measurement of the planetary geometric albedo, Ag, which is an indicator of the prese…
The stable climate of KELT-9b
Alonso, R.; Deleuil, M.; Erikson, A. +76 more
Even among the most irradiated gas giants, so-called ultra-hot Jupiters, KELT-9b stands out as the hottest planet thus far discovered with a dayside temperature of over 4500 K. At these extreme irradiation levels, we expect an increase in heat redistribution efficiency and a low Bond albedo owed to an extended atmosphere with molecular hydrogen di…
CHEOPS finds KELT-1b darker than expected in visible light. Discrepancy between the CHEOPS and TESS eclipse depths
Guterman, P.; Alonso, R.; Deleuil, M. +78 more
Recent studies based on photometry from the Transiting Exoplanet Survey Satellite (TESS) have suggested that the dayside of KELT-1b, a strongly irradiated brown dwarf, is significantly brighter in visible light than what would be expected based on Spitzer observations in the infrared. We observed eight eclipses of KELT-1b with CHaracterising ExOPl…