Puoko-nui: a flexible high-speed photometric system

We describe a portable CCD-based instrumentation system designed to efficiently undertake high time precision fast photometry. The key components of the system are (1) an externally triggered commercial frame-transfer CCD, (2) a custom Global Positioning System-derived time source and (3) flexible software for both instrument control and online analysis/display. Two working instruments that implement this design are described. The New Zealand-based instrument employs a Princeton Instruments (PI) 1k × 1k CCD and has been used with the 1 m telescope at Mt John University Observatory, while the other uses a newer 1k × 1k electron-multiplying CCD supplied by PI and is based at the University of Texas at Austin. We include some recent observations that illustrate the capabilities of the instruments.