2361633

Target RA (J2000): 174.960327 and deg Target Dec (J2000): 0.60357 and deg Gaia GMag: 12.8 Programme ID: CH_PR240003 PI of observing programme: Jiang Title of programme: Investigating Sub-Saturns through CHEOPS Observations: Envelope-Rich K2-19b and Envelope-Poor K2-19c Abstract: With more than 5000 discovered exoplanets the field of exoplanet research has entered it is a completely new era in which exotic planets – whose properties may be rare but which reveal important astrophysical processes – could be studied in detail through the combination of long-term observations by ground-based and space telescopes. The sub-Saturn planets K2-19b and K2-19c are exemplary cases for detailed study by CHEOPS in that they pose a challenge to the standard planet formation model of core-nucleated accretion. Here we propose to use CHEOPS to observe transits of K2-19b and K2-19c to use the TTV technique to further improve the mass measurements of these interesting planets with the goals on (1) studying the envelope fraction of K2-19b K2-19c and (2) studying the resonant relation between K2-19b and K2-19c. [truncated! Please see actual data for full text]