2377170

Target RA (J2000): 174.960327 and deg Target Dec (J2000): 0.60357 and deg Gaia GMag: 12.806 Programme ID: CH_PR240013 PI of observing programme: Villa Title of programme: Determining the architecture of the K2-19 system Abstract: The K2-19 system consists of three known transiting planets with two of them (planets b and c) close to 3:2 Mean Motion Resonance (MMR) and exhibiting large Transit Timing Variations (TTVs). Recent characterisation of the system revealed moderate eccentricities for these planets. However convergent migration whitin a protoplanetary disk does not favour significant orbital eccentricity excitation. An additional fourth planet has been proposed to reduce the eccentricities of planets b and c. To distinguish between the proposed scenarios additional transit observations are necessary. We aim to improve our understanding of the system’s architecture particularly its planetary eccentricities by observing three transits of K2-19c using CHEOPS to refine the TTV model. [truncated! Please see actual data for full text]