Tim Lawlor, James MacDonald, Department of Physics and Astronomy,
University of Delaware, Newark, DE 19711, USA
We have created a grid of evolutionary models which include models that exhibit born-again behavior, that is a very late helium pulse. Our models include a range of metallicities between Z = 0.001 and Z = 0.020. Mass loss was varied beginning at the peak of the last thermal pulse on the AGB. By doing this, we determined the range of helium mass at AGB departure that later produces a very late helium flash. We present here a direct comparison between our models and Sakurai's Object, as well as a comparison between Sakurai's Object and FG Sge, another object known to be undergoing a very late helium flash. By including this second object in our comparison, we find an important and significant distinction between the two objects. Given this new evidence, we make a prediction for Sakurai's Object: We expect it to increase in temperature and decrease slightly in luminosity within the next 20 to 70 years, and then to cool and brighten a second time with a longer time-scale of roughly 200 to 500 years. It will become as FG Sge is now.
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