Using the Gemini South telescope in Chile, a team of astronomers led by Joss Bland-Hawthorn of the University of Sydney revealed the faint, outer regions of the galaxy called NGC 300, showing that the galaxy is at least twice the size as thought previously. The findings suggest that our own Milky Way galaxy could also be bigger than the textbooks say.
But Joss’s telescope observations are just a part of his contribution to astronomy. He is also helping to pioneer a new technology known as astrophotonics, which uses optical systems to improve our understanding of the Universe.
According to Joss, Australia is leading some 25 per cent of the major developments in the astrophotonics field. The invention of the photonic lantern, a device some believed could never exist, was Australia’s first major success, Joss explains. The lantern splits light gathered by a multi-wavelength optical fibre into numerous outgoing single wavelengths, which can then be fed into a spectrograph to analyse the light. The lantern also has major potential in telecommunications and sensing applications.
Development of fibres that act as the most complex optical filters ever conceived are another success, says Joss. “They’re used to block the faint glow of the Earth’s atmosphere, which drowns out weak astronomical sources. We can now render the sky very dark indeed, as if we were in space.”
Instruments based on this technology are in the pipeline for the next generation of extremely large optical telescopes, such as the Giant Magellan Telescope. But they’re not the only potential use of astrophotonics in telescopes.