(Proposal ID) S16A-173

(PI) Hirano, Teruyuki

(Proposal Title)
ESPRINT II: A New Search for Transiting Planets Unveiled by K2

(Abstract)
We propose to observe the systems with planet candidates unveiled by K2, the 
second mission of the {Kepler} spacecraft. One issue concerning the 
original {Kepler} mission was that due to the faintness of stars observed by 
{Kepler}, follow-up observations (e.g., mass measurements and atmospheric 
characterizations) for outstanding systems were often difficult. The K2 
mission had changed this situation since K2 observes 10--20 times more bright 
stars (V<13), for which we can measure RVs and conduct further 
characterizations. We developed our own tool to analyze the K2 data, having 
detected dozens of planet candidates in each of the published fields. 
The proposed observation here involves validation of planet candidates for 
the seven most interesting targets in fields 2 and 3 using the combination 
of reconnaissance spectroscopy and high contrast imaging which allow us to 
statistically rule out the false positives. Our target list for planet 
validation in fields 2 and 3 has small (super-Earth and Neptune-sized) 
planets around late-type stars, including a possible brother of GJ 1214b 
hosted by a mid-M star. We also plan to measure radial velocities for 
relatively bright stars hosting super-Neptune to jovian-sized planet 
candidates, all of which are great targets for future characterizations.