School of Physics and Astronomy, University of Southampton, Southampton, United Kingdom; South African Astronomical Observatory, Observatory 7935, South Africa; Department of Astronomy, University of Cape Town, Cape Town, South Africa
Charles, P.A., School of Physics and Astronomy, University of Southampton, Southampton, United Kingdom, South African Astronomical Observatory, Observatory 7935, South Africa, Department of Astronomy, University of Cape Town, Cape Town, South Africa; Kotze, M.M., South African Astronomical Observatory, Observatory 7935, South Africa, Department of Astronomy, University of Cape Town, Cape Town, South Africa; Rajoelimanana, A., South African Astronomical Observatory, Observatory 7935, South Africa, Department of Astronomy, University of Cape Town, Cape Town, South Africa
The last 20 years have seen revolutionary developments of large-scale synoptic surveys of the sky, both from the ground (e.g., the MACHO and OGLE projects, which were targetted at micro-lensing studies) and in space (e.g., the X-ray All-Sky Monitor onboard RXTE). These utilised small and medium-sized telescopes to search for transient-like events, but they have now built up a huge database of long-term light-curves, thereby enabling archival research on a wide range of objects that has not been possible hitherto. This is illustrated with examples of long time-scale optical and X-ray variability studies from the field of X-ray binary research: the high-mass BeX binaries in the SMC (using MACHO and OGLE), and the bright galactic-bulge X-ray sources (mostly LMXBs, using RXTE/ASM). As such facilities develop greater capabilities in future and at other wavelengths (developments in South Africa will be described), real-time data processing will allow much more rapid follow-up studies with the new generation of queue-scheduled large telescopes such as SALT. © 2012 International Astronomical Union.