Quantifying the Accretion Rate of V1500 Cygni

V1500 Cyg is an old classical nova that harbors a highly magnetic white dwarfprimary. V1500 Cyg erupted in 1975, but recent infrared observations reveal asource with large amplitude variations that had been ascribed to irradiation ofthe secondary star by the hot primary. We find, however, that a substantialfraction of the orbitally modulated light is due to cyclotron emission,suggesting magnetic accretion is the dominant irradiation source. Thus, V1500Cyg has an accretion rate that is much higher than found in other old novae.Such anomalously high accretion rates could allow the mass of the white dwarfsin such systems to grow to the Chandrasekhar limit, and thus highly magnetic oldnovae are excellent candidates for producing Type Ia SNe. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]