Title of programme: Three Resonant Planets: Tracking the Nearby Multi-Planet System GJ9827
Abstract: We propose primary transit observations of three Super?Earth planets in the planetary system around a bright, nearby star, GJ 9827. We announced the detection of three super?Earth planets in 1:3:5 commensurability, the inner planet, GJ 9827 b having a period of 1.2 days. This is the nearest planetary system that Kepler or K2 has found, at 30 pc, and given its brightness is one of the top systems for follow?up characterization. There are several opportunities in the CHEOPS visibility windows to obtain all three transits in a short period of time, or separately. The proximity to 1:3:5 resonance is intriguing from a dynamical standpoint. The observations will provide a firm determination of the ephemerides in order to explore any transit timing variations and support follow?up observations from space and ground?based telescopes. Subsequent follow-up has indicated that there is a transit timing variation that may have been undetected during the K2 campaign, but should be easily detectable now. Due to the brightness of the host star, this planetary system is likely to be extensively observed in the years to come. Indeed, our team has acquired observations of the planets orbiting GJ9827 with Hubble in the ultraviolet. The proposed observations will provide an important foundation to planning and designing these and future observations, in particular atmospheric characterization with JWST.
Temporal Coverage
2020-10-23T11:38:00Z / 2020-10-23T14:56:00Z
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.
