An artist's impression of the double pulsar.
Image: Swinburne University

An astronomical software package developed by a Swinburne PhD student has helped astronomers pin down the secrets of a bizarre 'double pulsar,' opening up a range of new avenues for scientific discovery.

The double pulsar - the only known system where two pulsars roar around one another in orbit - was discovered in 2003. Since then, scientists have been excited about the possibilities it presented for testing Einstein's theories of gravity - but only if the exact distance between the pulsars and Earth could be determined.

According to Swinburne PhD student Adam Deller, astronomers have spent the past five years trying to solve this problem. "However distances in astronomy are notoriously difficult to measure," he said. "Despite persistent attempts, the available telescopes and instrumentation were not able to provide the necessary information to measure the distance to the pulsars."

However in 2005 Deller became involved in a large project to modernise Australia's telescope network, which was led by Professor Steven Tingay, head of Radio Astronomy at Curtin University of Technology, and Dr Tasso Tzioumis from CSIRO's Australia Telescope National Facility.

As part of this project he wrote a new software package to take data from all of the major Australian radio telescopes and combine them on Swinburne's supercomputer. This software replaced older dedicated processing hardware and allowed an increase in the sensitivity of the telescope network - a crucial aid to the study of very faint objects such as the double pulsar.

Using this new technology, astronomers were able to accurately measure the distance between the Earth and the double pulsar for the very first time. With this measurement came a pleasant surprise - the pulsars were almost optimally placed in the Galaxy to allow astronomers to test Einstein's General Theory of Relativity at unprecedented levels of precision - to 0.01 per cent.

For Deller's supervisor and Director of Swinburne's Centre for Astrophysics and Supercomputing Professor Matthew Bailes, this outcome was thrilling. "We can now say with confidence that before 2015, when Einstein's theory will be 100 years old, we'll know how well it stands up to experiment," he said.

Deller's software development will also facilitate advancement in Australian astronomy, as radio telescopes in Australia are ideally located to watch the pulsars. It was the giant 64 metre Parkes radio telescope (The Dish) that discovered the system and has been monitoring it ever since.

"It will now be straight forward to use Parkes to test Einstein's General Theory of Relativity and in particular the study of gravitational waves," said Bailes.

According to Tingay, these technical developments will also assist in a much larger effort to build the Square Kilometre Array (SKA), a multi-billion dollar telescope project that Australia is proposing to host.

"The SKA will need to support telescopes spread over 3000km. Our efforts in Australia with projects like the double pulsar distance measurement demonstrate Australia's readiness to support the infrastructure, technology and science required for the SKA," he said.

The results of the test by Deller, Bailes and Tingay will be published in the journal Science.

Deller was also recently awarded the prestigious Jansky Fellowship to work at the US national facility NRAO where his software is being adopted.