(Proposal ID) S16A-091

(PI) Tominaga, Nozomu

(Proposal Title)
Detection and Follow-up Observations of Type II Plateau Supernovae

(Abstract)
A shock breakout (SBO) is the brightest phenomenon in a core-collapse 
supernova. We have started SBO surveys with HSC from  the S14A semester. 
Our S14A-191, S14B-048, and S14B-061 observations detected ~20 SBO candidates 
and had confirmed the high-z nature of 6 objects (z>0.5), and our first paper 
on an SBO was submitted. However, the previous single-epoch follow-up 
observation at ~1 month later could not reveal their evolution nor detect 
supernova features. Thus, it is required to obtain multicolor light curves 
and spectra continuously from the SBO to the plateau. We propose 2-continuous-
night HSC imaging observations in the g band and immediate and continuous 
follow-up imaging and spectroscopic observations with GMOS, optimizing for 
relatively low-z SBOs (z<0.3). One of co-investigators also proposes a 
1-night Keck/LRIS coordinated observation via the California Institute of 
Technology to make maximal use of the HSC observation. Although we had 
proposed similar observations in 2015, the FOCAS observation was cancelled 
(S15A-092), and the HSC observation was performed only for ~3 hours with 
poor seeing (~1.4 arcsec, S15B-033). The unprecedented observational data 
over ~2 months comprehensively test theoretical models from the SBO to the 
plateau.