New observations of BS and BT Cnc were performed during the STEPHI VII campaign in 1996 February. An overall run of 115 hours of data was collected. Different methods have been used to analyse the time series, bringing the detection of 2 frequencies for BT Cnc and 3 frequencies for BS Cnc above the 99% confidence level. A comparison with the literature reveals that the dominant mode of BT Cnc (similar to 9.8 c/d) has kept excited over tens of years, while the secondary modes have not been the same all the time. However, during the very last years the two frequencies detected by us have been the only ones noticeably excited in the spectrum.

We recall the geometric and photometric properties of this electronographic camera and its use since it has been put into operation in Hawaii (1982). A program of deep sounding of the Universe was started in 19 85 ; deep plates, in U, B, V colors, were taken in the direction of the North galactic Pole. We show the preliminary results of this study. With a single plate, one measures faint objects up to the magnitude B = 25,7. The color-magnitude diagram of these objects is established : the fainter they are, the bluer they appear ; this gives information on the state of the galaxies in the Past.