PI: Michel Hillen, K.U.Leuven, Michel.Hillen@ster.kuleuven.be
Address: Instituut voor Sterrenkunde, Celestijnenlaan 200, Heverlee 3001, Belgium
CoI: Joanna Mikolajewska, NCAC Warsaw
CoI: Alain Jorissen, Institut d'Astronomie et d'Astrophysique, ULB
CoI: Tyl Dermine, Institut d'Astronomie et d'Astrophysique, ULB
CoI: Tijl Verhoelst, Instituut voor sterrenkunde, K.U.Leuven
CoI: Pieter Degroote, Instituut voor sterrenkunde, K.U.Leuven
CoI: Steven Bloemen, Instituut voor sterrenkunde, K.U.Leuven
Title: Resolving the Roche lobe filling giant in the recurrent nova T CrB: a solution to the ``continually embarrassing problem'' of symbiotic binaries?
Abstract: Current understanding of S-type symbiotics faces an embarrassing problem: different indirect methods for measuring the radii of the giants in these interacting binary systems give inconsistent results. The ellipsoidal variations observed in light curves result in radii twice as large as those inferred from v_\mathrmrot\sin i measurements. This discrepancy is directly related to the mode of mass transfer in these highly interacting systems. We propose interferometric observations with CHARA/CLIMB, at the highest angular resolution available in the near-IR, of a well-chosen target to resolve this issue by discriminating between two proposed solutions to the problem at hand: a wrong assumption in the v_\mathrmrot \sin i method or an adaptation of the Roche potential by the inclusion of radiation effects. Spatially resolving the tidal distortion of the red giant in T CrB (one of the best candidates to become a supernova Ia in our galaxy), will provide the much needed quantitative constraints to rule out any of above hypotheses and shed light on the mode of mass transfer occurring in one of the most fascinating objects in the local universe.
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