NOAO >   Observing Info >   Approved Programs >   2011A-0096

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Proposal Information for 2011A-0096


PI: Bradley E. Schaefer, Louisiana State University, schaefer@lsu.edu
Address: Physics Department, 243 Nicholson, Baton Rouge, Louisiana 70803, US

Title: Orbital Period Changes Across the Recent Eruptions of Two Recurrent Novae, the Dynamical Measure of the Ejected Mass, and Whether These Will Become Type Ia Supernovae

Abstract: U Scorpii is the archetypal recurrent nova (RN) and is one of the best candidates for being a progenitor of Type Ia supernovae, but only if the nova eruption ejects less mass than is accreted during the previous cycle. The mass accreted can be measured to within roughly a factor of two, but the usual method for *measuring* (and modeling) the ejected mass has 3 orders-of-magnitude uncertainty. The only solution is to measure the orbital period change across the eruption, and for this I have eclipse times to produce accurate pre-eruption orbital periods for U Sco (across both its 1999 and 2010 eruptions) and CI Aql (2000 eruption). This two-decade program with big implications is nearing completion, but a final year or two is needed to pull out the mass ejected and to answer the question (``Are RNe the progenitors of Ia supernovae?"). Also, the most critical U Sco eclipse times for the 2010 eruption are those just after the eruption, so the proposed 2011 eclipse times are required to get a mass ejected for the 2010 eruption.


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NOAO >   Observing Info >   Approved Programs >   2011A-0096

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