Gemini-GRACES high-quality spectra of Kepler evolved stars with transiting planets I. Detailed characterization of multi-planet systems Kepler-278 and Kepler-391

E. Jofré, J. M. Almenara, R. Petrucci +10

(abridged) Kepler-278 and Kepler-391 are two of the three evolved stars known to date on the RGB to host multiple short-period transiting planets. Moreover, these planets are among…