ECLIPSE MAPPING OF XY UMA

Observations in the temporal domain open up new windows on astrophysics thatsnapshot observations simply cannot address. We propose an eclipse timing androtational modulation observation of the RS CVn system XY UMa to further ourinvestigations of the morphologies of active stellar atmospheres. Earliereclipse mapping observations have given contradictory results: sometimes thecoronae appear compact (solarlike), at other times they appear extended.Uninterrupted observations longer than the stellar rotation period are needed toensure a view of the quiescent corona amidst the frequent flaring. Observationsspanning 3 stellar orbits will reveal the coronal scale heights, latitudes, andspatial scales down to 100,000 km, or about 5% of the stellar radius. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]