| 11 July 
              2001 | S-CAM, 
              the Worlds most advanced optical camera, captures eclipse of binary 
              star. | 
        
        Astronomers from the Mullard Space Science Laboratory joined 
          a team from the European Space Agency 
          in La Palma, Spain to use a totally new type of optical detector on 
          the William Herschel Telescope, part of the Isaac 
          Newton Group of Telescopes (ING).
        The 
          new instrument, named S-CAM 
          (Superconducting tunnel junction-CAMera) uses advanced detector elements 
          based on superconducting technology to register the arrival of individual 
          photons, and measure their wavelength (colour). These detectors are 
          the first to detect colour intrinsically in the optical band. 
          The instrument is cooled to below one degree kelvin to minimise all 
          possible noise, resulting in an almost perfect detector.
        The 
          astronomers were looking at extremely faint astronomical sources, which 
          vary rapidly, for example pulsars or binary star systems. These observations 
          would not have been possible using conventional optical CCD detectors, 
          because very rapid changes in light intensity cannot be measured.
        
                S-CAM (Photograph courtesy ESA).
 
                  S-CAM (Photograph courtesy ESA).
        
        Dr. 
          Mark Cropper, from the Mullard Space Science Laboratory, has been studying 
          binary star systems, known as magnetic cataclysmic variables, for more 
          than a decade. "This new detector allows us to look at changes 
          in the light from the system as it changes over small fractions of a 
          second. This is the first time we have been able to study the rapid 
          colour changes, which occur at the same time. From this we have been 
          able to find out which parts of the system are emitting at what brightness 
          and at what temperature - a sort of dissection process." Dr Cropper 
          added "that this allowed the energy generation and emission in 
          these binary stars to be much better understood." Such details 
          are far too small to be seen in normal images from telescopes on the 
          ground or in space.
        
           
            | Contacts: |  | 
           
            |  |  | 
           
            | Dr 
              Mark Cropper | 01483 
              204155 email: msc@mssl.ucl.ac.uk | 
           
            | MSSL 
                switchboard | 01483 
                274111  | 
           
            | MSSL 
                website |  |