Sydney University Stellar Interferometer (SUSI)

Brief Outline

SUSI seen from the north end of the 640m baseline.

The Sydney University Stellar Interferometer (SUSI) is a long-baseline optical interferometer located approximately 20km west of the town of Narrabri in northern New South Wales, Australia. SUSI is operated by staff from the Sydney Institute for Astronomy within the School of Physics at the University of Sydney. It is located at the Paul Wild Observatory, alongside the Australia Telescope Compact Array radio interferometer, and approximately 20km from Narrabri in northern New South Wales, Australia.

SUSI has been developed to tackle a range of problems in stellar astrophysics. In its current configuration observations are made with a single baseline selected from an array of fixed north-south baselines covering the range from 5 to 160m. Hardware is ready to be installed to enable baselines up to 640m, but installation is not a current priority as current science drivers do not require such extreme (<1 nanoradian or 0.2 milli-arcsec) spatial resolution. Small apertures, wavefront-tilt correction and rapid signal sampling are employed to overcome the effects of atmospheric turbulence, while optical path equality is maintained by a dynamic optical delay line.

SUSI is currently funded through to the beginning of 2013. In 2008, the beam-combination system was being upgraded to the Precision Astronomical Visible Observations (PAVO) beam combiner, with an expected limiting magnitude of 7, 10 simultaneous wavelength channels and spatial filtering that will enable ~1% precision observations. A version of this combiner has also been commissioned at the CHARA array, led by SUSI group member Dr Michael Ireland.

In addition, we are in the process of automating SUSI. One of the important first steps is a sky monitoring camera. See here for animations of previous nights (the stripes are an artifact that will be removed in Feb 2009). Both SUSI and CHARA can be operated from the new Remote Observing Center Sydney (ROCS).

----- There are several new PhD projects and honours PROJECTS on offer: interested parties should contact the director Dr Gordon Robertson or one of the other active SUSI group members.