  The Sloan Digital Sky Survey-II (SDSS-II) has embarked on a multi-year
project to identify and measure light curves for intermediate-redshift (0.05 <
z < 0.35) Type Ia supernovae (SNe Ia) using repeated five-band (ugriz) imaging
over an area of 300 sq. deg. The survey region is a stripe 2.5 degrees wide
centered on the celestial equator in the Southern Galactic Cap that has been
imaged numerous times in earlier years, enabling construction of a deep
reference image for discovery of new objects. Supernova imaging observations
are being acquired between 1 September and 30 November of 2005-7. During the
first two seasons, each region was imaged on average every five nights.
Spectroscopic follow-up observations to determine supernova type and redshift
are carried out on a large number of telescopes. In its first two three-month
seasons, the survey has discovered and measured light curves for 327
spectroscopically confirmed SNe Ia, 30 probable SNe Ia, 14 confirmed SNe Ib/c,
32 confirmed SNe II, plus a large number of photometrically identified SNe Ia,
94 of which have host-galaxy spectra taken so far. This paper provides an
overview of the project and briefly describes the observations completed during
the first two seasons of operation.
