Program: GN-2010A-Q-20

We have found an unexplained diversity in the UV spectra of intermediate redshift Type Ia supernovae (SNe Ia) which may arise from variations in progenitor metallicity. To understand the implications and any redshift-dependent biases in the use of SNe Ia for measurements of dark energy, we are undertaking a new HST ToO program from September 2009 - August 2010 to gather UV spectra of 35 local SNe Ia, taking advantage of two new local "rolling'' transient searches. Our sample also will be unique in having continuous photometric/spectroscopic coverage from early phases (LCOGT, Liverpool Telescope, Lick, Wise, Palomar, Keck, WHT, VLT). Here, we seek to exploit the rapid ToO mode of Gemini N and S to obtain the required early-phase confirmation spectra for candidates in 2010A, providing the classification upon which targets can be scheduled at HST. These rare early-phase spectra will also offer new opportunities in studying SNe Ia and their progenitors. In addition we seek to exploit the queue mode of Gemini to obtain a few maximum light spectra to be done in conjunction with our HST observations.