(Proposal ID) S16B-132

(PI) Hirano, Teruyuki

(Proposal Title)
ESPRINT III: 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 {\it Kepler} spacecraft. We developed our own tool to 
analyze the K2 pixel data, having detected dozens of planet candidates in each 
of the published fields. Our collaboration, named ESPRINT, has advantages over 
other similar K2 follow-up teams in that (1) we have experience and facilities 
for validating planets around cool stars, and (2) our pipeline has a higher 
sensitivity to short-period planets. Fully exploiting those advantages, we 
here focus on validation of small planets around M dwarfs, and mass 
measurements (confirmation) of ultra-short-period (USP) planet candidates 
around relatively bright stars. We propose to validate up to eight most 
interesting planetary systems around M dwarfs, selected from K2 fields 4, 5, 
and/or 8, by combining reconnaissance spectroscopy with HDS and high contrast 
(AO) imaging with IRCS. These planets could become great targets for future 
follow-up studies using high dispersion spectroscopy in the near infrared 
(e.g., Subaru/IRD). We also plan to measure radial velocities (RVs) for two 
relatively bright stars hosting USP planet candidates, which are possibly 
disintegrating.