Title of programme: Cloudiness of three warm Sub-Neptunes
Abstract: Substantial efforts have been made to analyze and interpret exoplanetary atmospheres this past decade. However, while the development of forward and retrieval codes, lead to atomic and molecular absorption discoveries in both emission and transmission spectroscopy, clouds remain difficult to characterize and detect. We want to assess the cloudiness of three warm Sub-Neptunes using CHEOPS bandpass in the optical. While there is no doubt that these planets have a light, hydrogen dominated, atmosphere, the presence of clouds or hazes in the upper atmosphere is more difficult to assess, and this can be investigated with an accurate optical measurement for which CHEOPS is in an excellent position to provide. The goals of our study are, first, to refine the planetary transit depth in the optical, and, secondly, by comparing the value found by CHEOPS in transmission, to atmospheric clear and cloudy forward models, confirm or refute the presence of clouds in the atmosphere of Sub-Neptunes. Besides, we want to compare CHEOPS value to previous atmospheric measurements of the targets, particularly with the Hubble Space Telescope in the near-infrared, and, constrain the cloudiness of this type of planets to better define observational strategies for the James Webb Space Telescope and ARIEL. CHEOPS observations offer the unique opportunity to study consistently the cloudiness of an intriguing population of planets.
Temporal Coverage
2022-08-03T20:40:00Z / 2022-08-04T08:12:00Z
Version
3.0
Mission Description
CHEOPS (Benz et al., https://doi.org/10.1007/s10686-020-09679-4) is a European Space Agency (ESA) mission in partnership with Switzerland with important contributions to the payload and the ground segment from Austria, Belgium, France, Germany, Hungary, Italy, Portugal, Spain, Sweden and the United Kingdom.
The satellite has a single payload comprising an ultra-high precision photometer covering the 330 - 1100 nm wavelength range in a single photometric band. Observations are made as part of the Guaranteed Time Observing Programme that is formulated by the CHEOPS Science Team, and the Guest Observers Programme through which the Community at large can apply for CHEOPS time.
