Our Mission The OPTICON Integrated Infrastructure Initiative brings together many of Europe's astronomical observatories, data centres and laboratories. Our goal is to identify opportunities where greater progress can be made by collaboration than by competition, and to take unified actions to achieve those agreed goals. Henk Spruit JRA3 Coordinator Max Planck Institute for Astrophysics, Box Garching Germany Telephone: John Davies OPTICON Project Scientist UK Astronomy Technology Centre, Blackford Hill Edinburgh, EH9 3HJ United Kingdom Telephone: +44 (0) E:mail Contacts OPTICON - The Optical Infrared Coordination Network for Astronomy JRA3 - High-speed astronomy OPTICON is funded by the European Commission under Contract RII3-CT With bigger telescopes, one can study fainter and more distant objects, but bigger telescopes also open new opportunities to study objects that vary rapidly in time, sometimes in milliseconds or less. Current detectors are far too slow to study these flickering objects. JRA3 is a technology development programme for detectors with time resolutions down to a microsecond which will sensitive enough to be useful for astronomy. Three different detector technologies are being pursued in parallel at 5 technology centres across Europe. In a complementary effort the corresponding high-speed controllers and data-reduction software are being developed. Flashing objects in the sky Most stars vary little and slowly, and can be observed adequately with existing astronomical hardware. However, some of the more interesting objects, vary extremely rapidly. White dwarfs which receive mass from a companion star (`accretion’) vary on time scales of a second and less, while accreting black holes and neutron stars vary on millisecond time scales. Some of the fastest variability is observed in the enigmatic gamma-ray bursts, where variations in less than a millisecond have been seen in X-rays. Though the bursts produce visible light as well as gamma rays, the technology to observe them at very short time scales in the visible is still to be developed. Other rapidly varying astronomical objects include `flare stars’ and `microquasars’. Participants The collaborating organisations are: Max Planck Institute for Extraterrestrial Physics Max Planck Institute for Astrophysics Landessternwarte Heidelberg UK Astronomy Technology Centre University of Cambridge National University of Ireland Nordic Optical Telescope Scientific Association European Southern Observatory Technology Development Three different technologies are being developed in this activity: Electron-multiplier CCDs. These are commercially available, but require additional development for astronomical use. Avalance photodiodes (APD). These deliver the fastest time resolution but must be configured into arrays of individual cells. pn-sensors. Specially developed electron-multiplied CCDs in deep-depletion technology with extended near-infrared sensitivity. Structure of an avalanche photodiode Wavelength response of pn-sensor Artist’s impression of a black hole accreting from a companion star, producing X-rays, visible light and a jet. Processes close to the hole cause it to vary on time scales of milliseconds. Photon