Periodic Reporting for period 1 - SPICE DUNE (A SpectroPhotometric Inquiry of Close-in Exoplanets around the Desert to Understand their Nature and Evolution)
Période du rapport: 2021-03-01 au 2022-08-31
The goal of SPICE DUNE is to determine the origin of the hot Neptune desert, a deficit of Neptune-size planets on very short orbits. This mysterious feature contains the imprint of processes that shaped the population of exoplanets orbiting close to their star - and further. The relative role and the coupling of these processes, in particular atmospheric evaporation and orbital migration on secular timescales, remain unclear. This is because we lack optimal observational tracers to validate and constrain numerical models of exoplanet evolution. SPICE DUNE thus aims at gathering observations of escaping atmospheres from gas giants to super-hot rocky planets all around the desert. These data will drive the development of self-consistent models of upper atmosphere then used to derive the planets' erosion rate. We will combine for the first time these erosion rates with measurement of the planets' orbital architecture to constrain population syntheses coupling long-term orbital and atmospheric evolution of close-in planets. This ambitious approach, exploiting advanced modelling informed by the most relevant tracers, will unveil the evolutionary tracks of exoplanets and bring insights into their nature.
The proposed research addresses high-priority questions related to the origins of close-in planets, and has implications for the origin of both extrasolar systems and our own solar system's evolution.
The proposed research addresses high-priority questions related to the origins of close-in planets, and has implications for the origin of both extrasolar systems and our own solar system's evolution.
Main work performed on WP AGATE:
- upgrade of the team's numerical code to simulate the upper atmosphere of giant planets, and development of a more detailed model to describe their thermosphere. Several associated publications are in preparation
- participation to several publications (see list) about the observation of atmospheric escape from gas-rich planets
- collaboration initiated to design and develop an instrument dedicated to measuring atmospheric escape signatures
Main work performed on WP JADE:
- development of a numerical code simulating the coupled atmospheric and dynamical evolution of a close-in planet system over secular timescales (Attia et al. 2021, A&A, 647, A40)
- development of a new technique to measure the orbital architecture of exoplanets. Used to discover a system with two planets on perpendicular orbits (Bourrier et al. 2021, A&A 654, A152), and now applied routinely to perform measurements of orbital architectures (eg Bourrier et al. 2022, A&A 663, A160)
Main work performed on WP JASPER:
- publications on the orbital and structural properties of ultra-short period planets are in press
Overall work on the project:
- over the first financial reporting period, the team has co-signed 30 articles in international refereed journals, including 4 as first authors.
- results have been disseminated through conferences, press releases and interviews
- the team obtained several open time observing programs on ground-based and space-borne instruments, and participated in guaranteed observation programs.
- upgrade of the team's numerical code to simulate the upper atmosphere of giant planets, and development of a more detailed model to describe their thermosphere. Several associated publications are in preparation
- participation to several publications (see list) about the observation of atmospheric escape from gas-rich planets
- collaboration initiated to design and develop an instrument dedicated to measuring atmospheric escape signatures
Main work performed on WP JADE:
- development of a numerical code simulating the coupled atmospheric and dynamical evolution of a close-in planet system over secular timescales (Attia et al. 2021, A&A, 647, A40)
- development of a new technique to measure the orbital architecture of exoplanets. Used to discover a system with two planets on perpendicular orbits (Bourrier et al. 2021, A&A 654, A152), and now applied routinely to perform measurements of orbital architectures (eg Bourrier et al. 2022, A&A 663, A160)
Main work performed on WP JASPER:
- publications on the orbital and structural properties of ultra-short period planets are in press
Overall work on the project:
- over the first financial reporting period, the team has co-signed 30 articles in international refereed journals, including 4 as first authors.
- results have been disseminated through conferences, press releases and interviews
- the team obtained several open time observing programs on ground-based and space-borne instruments, and participated in guaranteed observation programs.
Progress beyond the state of the art:
- development of a new technique to measure orbital architectures, giving access to smaller planets down to the Earth-size regime
- development of an advanced model coupling the atmospheric and dynamical secular evolution of close-in giant exoplanets
- ongoing work on a 3D model of giant planets upper atmospheres, coupling collision-less and fluid regimes
Expected results:
- a better knowledge of orbital architectures and thus migration pathways in systems bordering the Neptunian desert
- understanding the interplay between atmospheric and orbital evolution, and their relative roles in shaping the Neptunian desert
- developing a model allowing for a finer interpretation of absorption signatures from the upper atmosphere of giant planets
- development of a new technique to measure orbital architectures, giving access to smaller planets down to the Earth-size regime
- development of an advanced model coupling the atmospheric and dynamical secular evolution of close-in giant exoplanets
- ongoing work on a 3D model of giant planets upper atmospheres, coupling collision-less and fluid regimes
Expected results:
- a better knowledge of orbital architectures and thus migration pathways in systems bordering the Neptunian desert
- understanding the interplay between atmospheric and orbital evolution, and their relative roles in shaping the Neptunian desert
- developing a model allowing for a finer interpretation of absorption signatures from the upper atmosphere of giant planets