Optics for ULTRACAM on the NTT

ULTRACAM is a digital camera capable of taking up to 300 red, green and blue images every second. The instrument was built in 3 years by a consortium from the Universities of Sheffield, Warwick and the UK Astronomy Technology Centre in Edinburgh, using a £300,000 grant awarded by STFC. ULTRACAM saw "first light" in 2002 on the 4.2-m William Herschel Telescope (WHT) on La Palma and first light on the 8.2-m Very Large Telescope (VLT) in Chile in 2005. The latter is widely regarded as the world's most powerful telescope and ULTRACAM became both the first instrument to use its "Visitor Focus" and the first UK-built instrument to be mounted on the VLT. In 2010, we also commissioned ULTRACAM on the 3.5-m New Technology Telescope (NTT) in Chile.

To date, ULTRACAM has been awarded nearly 500 nights of telescope time to study white dwarfs, brown dwarfs, pulsars, black-hole/neutron-star X-ray binaries, gamma-ray bursts, extra-solar planets, cataclysmic variables, eclipsing binary stars, flare stars, ultra-compact binaries, asteroseismology and occultations by Solar System objects (e.g. Titan and Kuiper Belt Objects). The large quantity of observing time awarded to ULTRACAM on some of the world's finest telescopes is testament to the competitiveness of the science performed with the instrument. Over 100 refereed publications in major astronomical journals have resulted from this work, including 3 papers in Nature and 2 papers in Science.

This grant proposal requests funding to significantly improve the signal-to-noise ratio of ULTRACAM observations by providing it with new collimating optics for the NTT and a new set of high-throughput filters, to the benefit of all users in the European Southern Observatory (ESO) community.

ULTRACAM is a camera that operates at the boundaries of speed defined by detector noise performance and object brightness. Its development required and enabled the UK's Astronomy Technology Centre (UKATC) to develop and build a new high-speed data acquisition system from scratch. This "UCAM" system has gone on to be used in other UK astronomical instruments and to be sold as part of systems supplied by the UKATC outside the UK. Continued operation and exploitation of ULTRACAM for leading-edge astronomical research provides a platform to test modifications, updates and upgrades of the UCAM system, allowing the UKATC to maintain a competitive edge to this acquisition system.