Tara Murphy

Understanding the radio stars population with ASKAP, on the path to the SKA

Until recently, the population of radio-loud stars has been studied primarily through targeted observations of a small number of stars with previously identified indicators of magnetic activity; such as strong radio activity, flaring or variability in other wavebands, or the presence of chromospheric emission or absorption lines. Previous widefield radio surveys have typically consisted of only a few epochs (or a single epoch), which has limited our ability to distinguish stellar emission from background AGN. As a result it has been difficult to constrain population statistics such as the surface density and fraction of the population producing radio emission in a particular variable or spectral class. The Australian SKA pathfinder (ASKAP) telescope is transforming our understanding of radio star populations. For the first time we are able to monitor hundreds (and potentially 1000s) of stars at gigahertz radio frequencies. We can investigate timescales as short as seconds, with monitoring periods over months to years. In this talk I will present some of our results, including recently published work in which we monitor a sample of radio stars detected in circular polarisation searches of the multi-epoch ASKAP Variables and Slow Transients survey. Based on this work we anticipate detecting several hundred new radio stars for each year of our ASKAP survey, and tens of thousands in next generation all-sky surveys with the Square Kilometre Array. I will also discuss the prospects for current and future radio stars studies with ASKAP and the SKA, and potential for multi-wavelength collaborations.