Berkeley supernova Ia program. I.

In this first paper in a series, we present 1298 low-redshift (z<~0.2) optical spectra of 582 Type Ia supernovae (SNe Ia) observed from 1989 to 2008 as part of the Berkeley Supernova Ia Program (BSNIP). 584 spectra of 199 SNe Ia have well-calibrated light curves with measured distance moduli, and many of the spectra have been corrected for host-galaxy contamination. Most of the data were obtained using the Kast double spectrograph mounted on the Shane 3m telescope at Lick Observatory and have a typical wavelength range of 3300-10400{AA}, roughly twice as wide as spectra from most previously published data sets.

We present our observing and reduction procedures, and we describe the resulting SN Database, which will be an online, public, searchable data base containing all of our fully reduced spectra and companion photometry. In addition, we discuss our spectral classification scheme (using the SuperNova IDentification code, SNID; Blondin & Tonry, 2007ApJ...666.1024B), utilizing our newly constructed set of SNID spectral templates.