Search Publications
Discovery of a cold giant planet and mass measurement of a hot super-Earth in the multi-planetary system WASP-132
Bayliss, Daniel; Armstrong, David J.; Lendl, Monika +25 more
Hot Jupiters generally do not have nearby planet companions, as they may have cleared out other planets during their inward migration from more distant orbits. This gives evidence that hot Jupiters more often migrate inward via high-eccentricity migration due to dynamical interactions between planets rather than more dynamically cool migration mec…
A possible misaligned orbit for the young planet AU Mic c
Aigrain, S.; Alonso, R.; Deleuil, M. +98 more
The AU Microscopii planetary system is only 24 Myr old, and its geometry may provide clues about the early dynamical history of planetary systems. Here, we present the first measurement of the Rossiter-McLaughlin effect for the warm sub-Neptune AU Mic c, using two transits observed simultaneously with the European Southern Observatory's (ESO's) Ve…
Constraining the scattered light properties of LTT 9779 b using HST/WFC3 UVIS
Wakeford, Hannah R.; Cowan, Nicolas B.; Parmentier, Vivien +5 more
A planet's albedo is a fundamental property that sets its energy budget by dictating the fraction of incident radiation absorbed versus reflected back to space. Generally, optical eclipse observations have revealed the majority of hot, giant planets to have low albedos, indicating dayside atmospheres dominated by absorption instead of reflection. …
A closer look at LTT 9779b:The ESPRESSO endeavour to pierce the atmospheric veil
Palle, E.; López-Morales, M.; Jenkins, J. S. +9 more
Context. The proliferation of exoplanet discoveries, particularly within such exotic environments as the Neptune desert, challenges our understanding of planetary atmospheres undergoing intense irradiation. The unexpected discovery of LTT 9779 b, an ultra-hot Neptune deep within this desert offers a prime opportunity for in-depth atmospheric studi…
CHEOPS observations confirm nodal precession in the WASP-33 system
Alonso, R.; Deleuil, M.; Erikson, A. +86 more
Aims. We aim to observe the transits and occultations of WASP-33 b, which orbits a rapidly rotating δ Scuti pulsator, with the goal of measuring the orbital obliquity via the gravity-darkening effect, and constraining the geometric albedo via the occultation depth. Methods. We observed four transits and four occultations with CHEOPS, and employ a …
Transit-timing variations in the AU Mic system observed with CHEOPS
Guterman, P.; Alonso, R.; Deleuil, M. +86 more
Context. AU Mic is a very active M dwarf star with an edge-on debris disk and two known transiting sub-Neptunes with a possible third planetary companion. The two transiting planets exhibit significant transit-timing variations (TTVs) that are caused by the gravi tational interaction between the bodies in the system. Aims. Using photometrical obse…
Characterising TOI-732 b and c: New insights into the M-dwarf radius and density valley
Alonso, R.; Deleuil, M.; Erikson, A. +88 more
Context. TOI-732 is an M dwarf hosting two transiting planets that are located on the two opposite sides of the radius valley. Inferring a reliable demographics for this type of systems is key to understanding their formation and evolution mechanisms.
Aims: By doubling the number of available space-based observations and increasing the number…
CHEOPS in-flight performance. A comprehensive look at the first 3.5 yr of operations
Guterman, P.; Alonso, R.; Deleuil, M. +128 more
Context. Since the discovery of the first exoplanet almost three decades ago, the number of known exoplanets has increased dramatically. By beginning of the 2000s it was clear that dedicated facilities to advance our studies in this field were needed. The CHaracterising ExOPlanet Satellite (CHEOPS) is a space telescope specifically designed to mon…
The SOPHIE search for northern extrasolar planets: XIX. A system including a cold sub-Neptune potentially transiting a V = 6.5 star HD 88986
Bouchy, F.; Deleuil, M.; Moutou, C. +51 more
Transiting planets with orbital periods longer than 40 d are extremely rare among the 5000+ planets discovered so far. The lack of discoveries of this population poses a challenge to research into planetary demographics, formation, and evolution. Here, we present the detection and characterization of HD 88986 b, a potentially transiting sub-Neptun…
Constraining the reflective properties of WASP-178 b using CHEOPS photometry
Alonso, R.; Deleuil, M.; Erikson, A. +79 more
Context. Multiwavelength photometry of the secondary eclipses of extrasolar planets is able to disentangle the reflected and thermally emitted light radiated from the planetary dayside. Based on this, we can measure the planetary geometric albedo Ag, which is an indicator of the presence of clouds in the atmosphere, and the recirculatio…