干旱区生态环境知识资源中心

We present new multiband transit photometry of three small (R-p less than or similar to 6 R-circle plus), short-period (P less than or similar to 6 d) Kepler planet candidates acquired with the Gran Telescopio Canarias. These observations supplement the results presented in Colon & Ford and Colon, Ford & Morehead, where we used multicolour transit photometry of five Kepler planet candidates to search for wavelength-dependent transit depths and either validate planet candidates or identify eclipsing binary false positives within our sample. In those previous studies, we provided evidence that three targets were false positives and two targets were planets. Here, we present observations that provide evidence supporting a planetary nature for Kepler Object of Interest (KOI) 439.01 and KOI 732.01, and we find that KOI 531.01, a 6 R-circle plus planet candidate around an M dwarf, is likely a false positive. We also present a discussion of the purported ’sub-Jovian desert’ in the orbital period-planet radius plane, which cannot be easily explained by observational bias. Both KOI 439.01 and KOI 732.01 are likely planets located within the so-called desert and should be investigated with further follow-up observations. As only similar to 30 of the similar to 3600 currently active Kepler planet candidates are located within the sub-Jovian desert, it will be interesting to see if these candidates also survive the vetting process and fill in the gap in the period-radius plane. Confirming planets in this regime will be important for understanding planetary migration and evolution processes, and we urge additional follow-up observations of these planet candidates to confirm their nature.