PI: Richard R. Joyce, NOAO, email@example.com
Address: P.O. Box 26732, Tucson, AZ 85718-6732, USA
CoI: Kenneth Hinkle, NOAO
Title: Narrowband IR Imaging of Final Flash Stars
Abstract: Post-AGB stars can undergo a final episode of helium shell burning after the star has ejected a planetary nebula and has started on the white dwarf track. This ``final flash'' episode is very short lived and, although common, rarely observed. In 1996, V4334 Sgr (Sakurai's Object) was the first star to be followed with modern instrumentation during its final flash stage. Since then, this object has undergone dramatic changes in elemental abundances, effective photospheric temperature, and brightness in both the visible and near-infrared. Ejection of a dust shell in 1998 resulted in the star becoming optically invisible by 2000 and possibly currently undetectable in the K band. V605 Aql underwent nearly identical behavior beginning in 1919 and is now generally accepted to be a final flash object. CK Vul, originally observed in 1670 and thought to be a slow nova, has also now been shown to possess many characteristics of a final flash object, including a compact radio source and strong HeI emission at 1.083 (mu)m. This line, which implies the existence of a hot wind, may serve as a tracer of the expanding shell from the central star. We propose high spatial resolution imaging in the HeI emission line of these objects, which span over 300 years in final flash evolution.
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