Observations

Team , centered her strategy with an aim of detecting supernovæ with large (around 0.5) and very great (around 1) redshifts.

In practice, only the telescopes of 4m and more make it possible to reach these values of redshift. The redshifts limits for the telescopes of 2m being around 0.4-0.5.

It is obvious that in time of observation fixed, the number of objects discovered is proportional to the field of the instrument. In the Nineties, two telescopes of 4m were equipped with increasingly large instruments of imagery: the CTIO . With fields of the order of the 1/3 of square degree, one can discover several supernovæ Ia beyond z=1 per night of observation on these instruments.

The privileged access of the French community to the CFHT, as well as the division of the observations with other scientific programs, made it possible our group to regularly obtain time of observation on instrument CFH12K.