Searching for ripples in the cosmic Niagara Falls: Cataclysmic Variable Stars

This talk is about “UGSU cataclysmic variables” - one of the most interesting species in the variable star zoo (in my opinion). They’re actually not variable stars at all, because they are binary systems, in which a red star spills material onto a white dwarf, giving rise to periodic massive eruptions which can brighten the star from mag 15 to mag 9, easily within the range of a backyard telescope. They are very important systems in astronomy, because they are the precursors of the type 1a supernovae, which are used to measure the Hubble-Lemaître constant, and the accelerating expansion of the universe. The light curves of these systems are very interesting - they show ‘wobbles’ which reveal a lot of what’s going on in the binary system and the accretion disk. Last year, I observed a southern sky system called VW Hyi, which was first characterised by astronomers from New Zealand and Australia. In addition to the ‘usual’ variations - known as ’superhumps’, I found hints of a different type of variation, but the data were not conclusive enough to confirm it. So this year, with some partners in crime, I’m collecting and analysing data on a number of similar systems to look for extra detail in the light curves of these interesting systems. If you are inspired by this talk you can join the hunt!

Dr Ian Kemp (ICRAR, ASNSW)

started his professional life in academic research - with a degree, PhD and postdoc in Materials Science. He then went off to work in Industry and government for a while (25 years) before getting back to research and obtaining a Masters degree in Astronomy. He currently works as a research scientist at the International Centre for Radio Astronomy Research (ICRAR) in Perth - working partly on ‘big data’ (i.e., extremely big, massive data) and partly on astrophysics research. https://www.icrar.org/people/ikemp/