Title of programme: Axis 1 - Architecture of Resonant Chains (ARC)
Abstract: Resonant chains are gold mines for fueling our understanding of planetary systems. The minute details of their architectures encode the history of their formation: the order of the capture of the planets in the chain (Delisle 2017), the local shape of the proto-planetary disc and its dispersal (e.g. Nesvorny et al 2022) and the long-term evolution of the system through tidal dissipation (e.g. Papaloizou et al 2018). The high multiplicity of these systems also makes them especially valuable to constrain our models of the formation of planetary systems (See Emsenhuber et al 2022 and other papers of the NGPPS series) since all the planets have to form in the same environment, and the relative fragility of the configuration ensures that no violent evolution (e.g. close encounters/impacts) occurred after the dissipation of the proto-planetary disc (Leleu et al 2021). In addition, the transit timing variations induced by the compactness of the systems allow for precise mass determination, down to a few per cent in the case of Trappist-1 (Agol et al 2021). This allows an in-depth characterization of moderately insolated rocky planets and mini-Neptune, with a precision which is rarely reachable through radial velocities, enabling studies of their interiors and atmospheres. The brightness of the current targets of the program (Gaia band mag 11 for TOI178, 12 for K2-138, 8.4 for TOI1835) allows to combine RVs and photometric measurements. The two methods have a great synergy, as TTVs allow for in-depth characterization of the resonant configuration, while RVs can constrain the mass of non-resonant planets and characterize the non-transiting part of the system. For all these reasons, these systems are also golden targets for the James Webb Space Telescope. The program aims to complete, understand and constrain the resonant architecture and planetary masses of key multi-planetary systems, as well as discovering new chains of resonances. This will be achieved by predicting and confirming missing planets in a resonant chain based on the known architecture, and a long-term TTV follow-up of the systems. This is an iterative process: the prediction and confirmation of planets increase the interest for a given system for an in-depth TTV characterization, while a better characterization of the system can point toward missing planets and lead to new detections.
Temporal Coverage
2023-10-08T11:38:51Z / 2023-10-08T23:04:00Z
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.
