SEARCH FOR TYPE Ia SUPERNOVAE
AT REDSHIFT $z \sim 0.1$ WITH EROS2

N. REGNAULT
Laboratoire de l'Acc\'el\'erateur Lin\'eaire,
IN2P3-CNRS et Universit\'e de Paris-Sud, BP 34, F-91898 Orsay Cedex

Abstract:
Type Ia supernovae (SNIa) are powerful cosmological distance indicators and have been used for measuring cosmological parameters such as the Hubble constant, $H_0$, and the deceleration parameter, $q_0$. These measurements rely on empirical correlations between absolute peak luminosities and other observables, like the postmaximum decline rate, or the color at maximum. Since the total number of well observed nearby SNIa is still small, these correlations are not yet fully understood. In 1997, the EROS2 Collaboration launched an intensive search for SNIa at $z \sim 0.05 - 0.2$. Our last search, in the spring of 1999 was performed in the framework of a worldwide consortium led by the {\em Supernova Cosmology Project}. It aimed at providing an independent set of high quality light curves and spectra, to study further the SNIa properties. In the following, we briefly describe our search procedure and the status of our analysis of the photometric data.