55 Cancri e's occultation captured with CHEOPS

Abstract

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 detection of 55 Cnc e's occultation with an average depth of $12\pm 3$ ppm. We derive a corresponding 2-$\sigma$ upper limit on the geometric albedo of $A_g<0.55$ once decontaminated from the thermal emission measured by Spitzer at 4.5$\mu$m. CHEOPS's photometric performance enables, for the first time, the detection of individual occultations of this super-Earth in the visible and identifies short-timescale photometric corrugations likely induced by stellar granulation. We also find a clear 47.3-day sinusoidal pattern in the time-dependent occultation depths that we are unable to relate to stellar noise, nor instrumental systematics, but whose planetary origin could be tested with upcoming JWST occultation observations of this iconic super-Earth.

arXiv commentIn press. Accepted for publication in Astronomy and Astrophysics on 13 October 2022. 10 pages, 7 figures and 3 tables

References in corpus (65)

• A new extensive library of PHOENIX stellar atmospheres and synthetic spectra
• The California-Kepler Survey. III. A Gap in the Radius Distribution of Small Planets
• Kepler planets: a tale of evaporation
• Radial velocity planets de-aliased. A new, short period for Super-Earth 55 Cnc e
• The Transit Light Curve Project. IX. Evidence for a Smaller Radius of the Exoplanet XO-3b
• The CHEOPS mission
• The connection between stellar granulation and oscillation as seen by the Kepler mission
• Compositional imprints in density-distance-time: a rocky composition for close-in low-mass exoplanets from the location of the valley of evaporation
• A Super-Earth Transiting a Naked-Eye Star
• Hot super-Earths stripped by their host stars
• Five Planets Orbiting 55 Cancri
• A Study of the Shortest-Period Planets Found With Kepler
• Density and Eccentricity of Kepler Planets
• Detection of an atmosphere around the super-Earth 55 Cancri e
• Chemistry of Silicate Atmospheres of Evaporating Super-Earths
• Detection of a transit of the super-Earth 55 Cnc e with Warm Spitzer
• The TRAPPIST survey of southern transiting planets. I. Thirty eclipses of the ultra-short period planet WASP-43 b
• TESS Discovery of an ultra-short-period planet around the nearby M dwarf LHS 3844
• Hint of a transiting extended atmosphere on 55 Cancri b
• Variability in the super-Earth 55 Cnc e
• Detection of Thermal Emission from a Super-Earth
• Atmosphere-interior exchange on hot rocky exoplanets
• Expected performances of the Characterising Exoplanet Satellite (CHEOPS) III. Data reduction pipeline: architecture and simulated performances
• Hot-Jupiters and hot-Neptunes: a common origin?
• The 55 Cnc system reassessed
• 55 Cancri: Stellar Astrophysical Parameters, a Planet in the Habitable Zone, and Implications for the Radius of a Transiting Super-Earth
• Precise time-series photometry for the Kepler-2.0 mission
• Improved precision on the radius of the nearby super-Earth 55 Cnc e
• Migration-driven diversity of super-Earth compositions
• Statistical Characterization of Hot Jupiter Atmospheres using Spitzer's Secondary Eclipses
• The 55 Cancri Planetary System: Fully Self-Consistent N-body Constraints and a Dynamical Analysis
• Transit detection of the long-period volatile-rich super-Earth ${\nu }^2$ Lupi d with $CHEOPS$
• Linking the Climate and Thermal Phase Curve of 55 Cancri e
• Absence of a metallicity effect for ultra-short-period planets
• Reliable inference of exoplanet light curve parameters using deterministic and stochastic systematics models
• Search for water in a super-Earth atmosphere: High-resolution optical spectroscopy of 55 Cancri e
• A Case for an Atmosphere on Super-Earth 55 Cancri e
• Bayesian analysis of interiors of HD 219134b, Kepler-10b, Kepler-93b, CoRoT-7b, 55 Cnc e, and HD 97658b using stellar abundance proxies
• Search for an exosphere in sodium and calcium in the transmission spectrum of exoplanet 55 Cancri e
• Marginalising instrument systematics in HST WFC3 transit lightcurves
• No Evidence for Lunar Transit in New Analysis of Hubble Space Telescope Observations of the Kepler-1625 System
• The orbital phases and secondary transit of Kepler-10b - A physical interpretation based on the Lava-ocean planet model -
• K2 and Spitzer phase curves of the rocky ultra-short-period planet K2-141 b hint at a tenuous rock vapor atmosphere
• Search for a habitable terrestrial planet transiting the nearby red dwarf GJ 1214
• Observability of Evaporating Lava Worlds
• No escaping helium from 55 Cnc e
• Most super-Earths formed by dry pebble accretion are less massive than 5 Earth masses
• CHEOPS Precision Phase Curve of the Super-Earth 55 Cnc e
• The Albedos of Kepler's Close-in super-Earths
• CHEOPS geometric albedo of the hot Jupiter HD 209458b
• Improving transit characterisation with Gaussian process modelling of stellar variability
• Mass, radius, and composition of the transiting planet 55 Cnc e : using interferometry and correlations
• Confirming Variability in the Secondary Eclipse Depth of the Super-Earth 55 Cancri e
• Arid or Cloudy: Characterizing the Atmosphere of the super-Earth 55 Cancri e using High-Resolution Spectroscopy
• A Survey for Very Short-Period Planets in the Kepler Data
• Cloud formation in metal-rich atmospheres of hot super-Earths like 55 Cnc e and CoRot7b
• Low Albedo Surfaces of Lava Worlds
• A Near-Infrared Chemical Inventory of the Atmosphere of 55 Cancri e
• The PEPSI Exoplanet Transit Survey (PETS) I: Investigating the presence of a silicate atmosphere on the super-Earth 55 Cnc e
• High-precision multi-wavelength eclipse photometry of the ultra-hot gas giant exoplanet WASP-103 b
• Multi-season optical modulation phased with the orbit of the super-Earth 55 Cnc e
• Connecting photometric and spectroscopic granulation signals with CHEOPS and ESPRESSO
• HORuS transmission spectroscopy of 55 Cnc e
• Weak evidence for variable occultation depth of 55 Cnc e with TESS
• Reassessing the Evidence for Time Variability in the Atmosphere of the Exoplanet HAT-P-7 b

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• A secondary atmosphere on the rocky exoplanet 55 Cancri e
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• Characterising the Atmosphere of 55 Cancri e: 1D Forward Model Grid for Current and Future JWST Observations
• Dark skies of the slightly eccentric WASP-18 b from its optical-to-infrared dayside emission
• Extreme Weather Variability on Hot Rocky Exoplanet 55 Cancri e Explained by Magma Temperature-Cloud Feedback
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