R. Schulz1, J. Stüwe2, D. Martin3, A. Stankov3, C. Erd3, T. Peacock3, P.Verhoeve3, T. Ho1
1ESA Research and Scientific Support Dep., ESTEC, Noordwijk, The Netherlands
2Sterrewacht Leiden, The Netherlands. 
3ESA Science Payloads and Adv. Concepts Office, ESTEC, Noordwijk, The Netherlands

                       
The transits of three extra-solar planets were monitored at the ESA Optical Ground Station 
with the S-CAM3, an ultra fast photon counting camera consisting of an array of 
superconducting tunnel junction detectors, working at a temperature of 300 mK. Its sensitive 
detectors measure the photon arrival times to microseconds and determine its color while 
essentially being noise free, only limited by sky background photons. The camera therefore 
provides high speed low resolution spectra (spectral resolution: 35nm at 500 nm) between 320 
nm and 800 nm.  In August 2006 we observed the transits of HD 209458, HD 189733 and TrES-1 
and a secondary transit of HD 189733. Full transit light curves could be obtained in all 
cases with a time resolution of 3 seconds. The first results of the analysis of the ingress 
and egress phases of these light curves will be presented.