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   72012
   We propose coordinated X-ray/UV/radio observations of the short-period
   RS CVn binary ER Vul using ASCA, HST/STIS, and ground-based radio
   telescopes. ER Vul contains two rapidly-rotating G dwarfs that allow
   study of coronal and chromospheric activity on solar-like stars at
   their highest activity levels. Our ASCA observations would cover three
   orbits (period =0.69d) of this partially-eclipsing binary, allowing
   study of coronal variability due to flaring and a search for phase-
   dependent orbital variability. The coronal X-rays and radio
   observations will be sensitive to flaring on few minute timescales,
   while the UV medium-resolution echelle spectra will probe the spatial
   structuring of cooler plasma through plage orbital modulation, eclipse
   obscuration, and Doppler location of flares.
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