We present the EROS nearby supernova (z∼0.02−0.2) search and the
analysis of the first year of data (1997). A total of 80 square degrees were
surveyed. Eight supernov{\ae} were detected, four of which were
spectroscopically identified as type Ia supernov{\ae}. The search efficiency
was determined with a Monte-Carlo simulation taking into account the
efficiencies for both supernova detection and host galaxy identification.
Assuming that for a given galaxy the supernova rate is proportional to the
galactic luminosity, we compute a type Ia supernova explosion rate of:
{\cal R} = 0.44 {}_{-0.21}^{+0.35} {}_{-0.07}^{+0.13} h^2: / 10^{10}
\lbsun / 100 {\rm yrs} at an average redshift of ∼0.1 where the errors
are respectively statistical and systematic (type misidentification included).Comment: 8 pages, 6 figures, accepted in A&