Spectroscopic detection of type Ia supernovae in the Sloan Digital Sky Survey

We present the results of a novel new search of the first data release from the Sloan Digital Sky Survey (SDSS-DR1) for the spectra of supernovae (SNe). The use of large spectroscopic galaxy surveys offers the prospect of obtaining improved estimates of the local SN rate, with the added benefit of a very different selection function to that of conventional photometric surveys. In this Letter we present an overview of our search methodology and the details of 19 Type Ia SNe found in SDSS-DR1. The SN sample is used to make a preliminary estimate, Gamma(Ia) = (0.4 +/- 0.2) h(2) SNu, of the cosmological SN rate.