The short lives of hard-living, fast burning, high mass stars

2015 L'Oréal-UNESCO For Women in Science Fellow Shari Breen (Credit: L'Oréal Australia)Dr Shari Breen, astronomer, CSIRO, Sydney

We are made of star stuff. The nitrogen in our DNA, the calcium in our teeth and the iron in our blood were all made in high mass stars that burnt briefly and brightly before exploding. Dr Shari Breen is using ‘The Dish’ at Parkes and a network of international telescopes to understand the life cycle and evolution of these stars. For her the 1,000 tonne Parkes radio telescope is an old friend that creaks and grumbles as she guides it across the sky, hunting for high mass stars. She will use her L'Oréal-UNESCO For Women in Science Fellowship to develop her use of masers (laser-like beams of intense radio waves) to investigate these stars.

Shari is an astronomer with CSIRO Astronomy and Space Science in Sydney.

Shari was drawn to radio astronomy during her degree at the University of Tasmania. Using maths and physics to discover the secrets of the Universe appealed to her. Soon she was making her first visit to ‘The Dish’ for her PhD project in which she investigated hundreds of high mass stars. When she first saw the 64 metre telescope she was terrified; realising what an opportunity and responsibility it was to drive this Grand Dame of radio astronomy. Today Shari works with large telescopes around the world. But ‘The Dish’ is still her favourite instrument, like an old and reliable friend. In the 1970s TV science show Cosmos, Carl Sagan famously announced “We are made of star stuff”. His statement is more than rhetoric, it is literally true. The hydrogen in the water in our bodies, and our oceans, is made by small stars like our sun. But most of the elements in our bodies, and the world around us, were made in much denser and larger stars with ten or more times the mass of our sun. But the evolution of these large stars is a mystery. “Everything is tied together,” says Shari. “If you don’t understand how a star forms there are many other things that you can’t explain. High mass stars have shaped galaxies throughout the Universe.”

 Video at 1080p and overlay without sound available for download here. 

High mass stars live hard and die young. While our sun will have a lifespan of nearly ten billion years, high mass stars live for as little as one hundredth of that time. Some spend ten million years burning hydrogen, then a million years burning helium, a thousand years burning carbon, and then eventually burning silicon before blowing up as a supernova. The gold in our jewellery was created in the final seconds of the life of a high mass star. But how are they created? That’s what Shari wants to know. High mass stars form in parts of the galaxy full of gas and dust so it's hard to see them—and if we can’t see them we can’t be absolutely sure what’s going on. This is where radio waves such as those detected by ‘The Dish’ come in handy. We can’t use light to see through the clouds of gas and dust. But radio waves shine through and Shari has shown that certain radio waves (masers) can reveal the timelines for the formation and evolution of these stars. Masers form naturally in high mass stars sending laser-like beams of intense radio waves across the galaxy. Many different kinds of maser form over the life of these stars and Shari has shown that she can track the formation and evolution of a star through its masers. Many of her colleagues around the world were initially sceptical, but Shari’s detailed and methodical work has confirmed the potential of masers, and she has used them to create the quantitative evolutionary timeline for the formation of high mass stars. Her leadership in the field led to her winning an Australian Research Council Discovery Early Career Researcher Award (ARC DECRA). Now Shari will use her L’Oréal-UNESCO Fellowship to validate her approach and answer one of the most fundamental unsolved mysteries of our Universe - how do gas clouds turn into stars?
2015 L’Oréal-UNESCO For Women in Science Fellow Shari Breen (Credit: L’Oréal Australia)
2015 L’Oréal-UNESCO For Women in Science Fellow Shari Breen (Credit: L’Oréal Australia)
2015 L’Oréal-UNESCO For Women in Science Fellow Shari Breen (Credit: L’Oréal Australia)
2015 L’Oréal-UNESCO For Women in Science Fellow Shari Breen (Credit: L’Oréal Australia)

Qualifications

2010 PhD (astronomy), The University of Tasmania, Hobart
2005 Bachelor of Science (Honours), The University of Tasmania, Hobart

Career highlights, awards, fellowships, grants

2015 Two week study tour of Chile, including presentation at an international conference and a week working at the University of Chile, Chile
2013–2015 ARC Discovery Early Career Researcher Award (DECRA), Tracing the evolution of high mass stars: combining maser evolutionary timelines with chemical clocks
2014 Invited to work with colleagues at National Radio Astronomy Observatory and Boston University, Boston, USA
2014 Study tour, invited presentation and collaboration with University of Manchester, UK
2014 Invited presentation, National Astronomical Observatory of Japan, Tokyo, Japan
2014 Study tour and invited presentation National Astronomical Observatory of Japan and Yamaguchi University, Japan
2013 Invited review presentation, Australia Telescope Compact Array's 25th Birthday Conference, Narrabri
2013 Extended study trip to the University of Manchester, Manchester, UK
2010 Bolton Fellowship at CSIRO Astronomy and Space Science
2009 Best Galactic Astronomy Poster, Australia Telescope National Facility Synthesis School, Narrabri
2007–2010 CSIRO Postgraduate Scholarship
2007–2013 Tasmanian Graduate Research Scholarship
2005–2006 Australia Telescope National Facility Summer Vacation Scholarship

Top five publications

Breen SL, Ellingsen SP, Caswell JL, Lewis BE (2010) 12.2-GHz methanol masers towards 1.2-mm dust clumps: quantifying high mass star formation evolutionary schemes, Monthly Notices of the Royal Astronomical Society 401: 2219–2244. (Impact factor 5.521, 69 citations) Walsh AJ, Breen SL, Britton T, Brooks KJ, Burton MG, Cunningham MR, Green JA, Harvey-Smith, L, Hindson L, Hoare MG, Indermuehle B, Jones PA, Lo N, Longmore SN, Lowe V, Phillips CJ, Purcell CR, Thompson MA, Urquhart JS, Voronkov MA, White GL, Whiting MT (2011) The H2O Southern Galactic Plane Survey (HOPS)–I. Techniques and H2O maser data, Monthly Notices of the Royal Astronomical Society 416: 1764–1821. (Impact factor 5.521, 59 citations) Breen SL, Caswell JL, Ellingsen SP, Phillips CJ (2010) Water masers accompanying OH and methanol masers in star formation regions, Monthly Notices of the Royal Astronomical Society 406: 1487–1532. (Impacts factor 5.521, 54 citations) Breen SL, Ellingsen SP, Caswell JL, Green JA, Voronkov MA, Fuller GA, Quinn LJ, Avison A (2011) Statistical properties of 12.2 GHz methanol masers associated with a complete sample of 6.7 GHz methanol masers, Astrophysical Journal 733: 80–97. (Impact factor 6.733, 29 citations) Breen SL, Ellingsen SP, Contreras Y, Green JA, Caswell JL, Stevens JB, Dawson JR, Voronkov MA (2013) Confirmation of the exclusive association between 6.7-GHz methanol masers and high mass star formation regions, Monthly Notices of the Royal Astronomical Society 435: 524. (Impact factor 5.521, 22 citations)