| Abstract: | I will discuss our recent results studying light curves of hydrogen-rich supernovae during the first few days after explosion. The first days of emission encode important information about the physical system, and it is possible to relate the early-time light curve to the radius of the progenitor star by using shock-cooling models. I will show the first systematic application of these models to data from the Palomar Transient Factory (PTF). I will also discuss improved observing strategies to obtain more constraining results in the future. One important question is the effect of circumstellar material on the light curves, motivating systematic spectroscopic sequencing of these events. To this end, we have joined the Son Of X-Shooter (SOXS) collaboration. SOXS is a medium resolution (R~4500) spectrograph spanning 0.35-2 um designed for ESO’s 3.6m New Technology Telescope. We have designed the UV-VIS arm of the SOXS and will construct it at the Weizmann Institute. Our design divides the spectrum into several channels, allowing optimization for each narrow part of the spectrum. We estimate a 50-100% improvement in throughput relative to a classical 4-C echelle design. SOXS has passed a preliminary design review, will go through a final design review in July, and is planned to be on the telescope in late 2020. |