Search Publications
Examining the orbital decay targets KELT-9 b, KELT-16 b, and WASP-4b, and the transit-timing variations of HD 97658 b
Alonso, R.; Deleuil, M.; Erikson, A. +87 more
Context. Tidal orbital decay is suspected to occur for hot Jupiters in particular, with the only observationally confirmed case of this being WASP-12b. By examining this effect, information on the properties of the host star can be obtained using the so-called stellar modified tidal quality factor Q*', which describes the eff…
Investigating the visible phase-curve variability of 55 Cnc e★
Alonso, R.; Deleuil, M.; Erikson, A. +87 more
Context. 55 Cnc e is an ultra-short period super-Earth transiting a Sun-like star. Previous observations in the optical range detected a time-variable flux modulation that is phased with the planetary orbital period, whose amplitude is too large to be explained by reflected light and thermal emission alone.
Aims: The goal of the study is to i…
The geometric albedo of the hot Jupiter HD 189733b measured with CHEOPS
Guterman, P.; Alonso, R.; Deleuil, M. +84 more
Context. Measurements of the occultation of an exoplanet at visible wavelengths allow us to determine the reflective properties of a planetary atmosphere. The observed occultation depth can be translated into a geometric albedo. This in turn aids in characterising the structure and composition of an atmosphere by providing additional information o…
The extremely high albedo of LTT 9779 b revealed by CHEOPS. An ultrahot Neptune with a highly metallic atmosphere
Deleuil, M.; Scandariato, G.; Hoyer, S. +11 more
Context. Optical secondary eclipse measurements of small planets can provide a wealth of information about the reflective properties of these worlds, but the measurements are particularly challenging to attain because of their relatively shallow depth. If such signals can be detected and modeled, however, they can provide planetary albedos, therma…
55 Cancri e's occultation captured with CHEOPS
Alonso, R.; Deleuil, M.; Erikson, A. +73 more
Past occultation and phase-curve observations of the ultra-short period super-Earth 55 Cnc e obtained at visible and infrared wavelengths have been challenging to reconcile with a planetary reflection and emission model. In this study, we analyse a set of 41 occultations obtained over a two-year timespan with the CHEOPS satellite. We report the de…
Connecting photometric and spectroscopic granulation signals with CHEOPS and ESPRESSO
Alonso, R.; Deleuil, M.; Erikson, A. +83 more
Context. Stellar granulation generates fluctuations in photometric and spectroscopic data whose properties depend on the stellar type, composition, and evolutionary state. Characterizing granulation is key for understanding stellar atmospheres and detecting planets.
Aims: We aim to detect the signatures of stellar granulation, link spectrosco…
TOI-5678b: A 48-day transiting Neptune-mass planet characterized with CHEOPS and HARPS★
Alonso, R.; Bouchy, F.; Deleuil, M. +92 more
Context. A large sample of long-period giant planets has been discovered thanks to long-term radial velocity surveys, but only a few dozen of these planets have a precise radius measurement. Transiting gas giants are crucial targets for the study of atmospheric composition across a wide range of equilibrium temperatures and, more importantly, for …
A new dynamical modeling of the WASP-47 system with CHEOPS observations
Alonso, R.; Deleuil, M.; Erikson, A. +80 more
Among the hundreds of known hot Jupiters (HJs), only five have been found to have companions on short-period orbits. Within this rare class of multiple planetary systems, the architecture of WASP-47 is unique, hosting an HJ (planet-b) with both an inner and an outer sub-Neptunian mass companion (-e and -d, respectively) as well as an additional no…
Refined parameters of the HD 22946 planetary system and the true orbital period of planet d★
Alonso, R.; Deleuil, M.; Erikson, A. +85 more
Context. Multi-planet systems are important sources of information regarding the evolution of planets. However, the long-period planets in these systems often escape detection. These objects in particular may retain more of their primordial characteristics compared to close-in counterparts because of their increased distance from the host star. HD…
A full transit of v2 Lupi d and the search for an exomoon in its Hill sphere with CHEOPS
Guterman, P.; Alonso, R.; Deleuil, M. +90 more
The planetary system around the naked-eye star v2 Lupi (HD 136352; TOI-2011) is composed of three exoplanets with masses of 4.7, 11.2, and 8.6 Earth masses (M⊕). The TESS and CHEOPS missions revealed that all three planets are transiting and have radii straddling the radius gap separating volatile-rich and volatile-poor super…