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Somewhat erratic comma unpredictable long-term starspot cycles of late-type stars are relevant for understanding the Sun.s analogous high-energy modulations comma in turn crucial to Earth-impacting d_commaSpace Weatherd_comma (SW). Similarly comma stellar SW counterparts can have equivalent comma or more severe comma adverse effects on their exoplanets. The solar decadal oscillations are symptomatic of a deep-seated magnetic pump -- the Dynamo -- whose internal workings remain elusive. Key questiondoublePoint is Sun.s 11-year cycle normal comma or instead a transition statequestionMark A 3-year addition to earlier long-term joint Chandra-HST programs (previously involving Alpha Cen CORCHETE_OPENG2V+K1VCORCHETE_CLOSE and Procyon CORCHETE_OPENF5IVCORCHETE_CLOSE) comma will be carried out for two new targets comma the nearby binaries Xi Bootis (G8V+K4) and 70 Ophiuchi (K0V+K5V). The HST part of the program will measure FUV subcoronal (Tvirgul100 comma 000 K) emission lines comma like Si IV 140 nm comma C IV 155 nm comma and density-sensitive O IV 140 nm comma as well as important chromospheric (Tvirgul10 comma 000 K) features comma like O I 130 nm comma C II 133 nm comma and C I 165 nm comma in both pairs of stars comma with one COS visit per system each year. Analyses of these emissions comma including dynamical information encoded in Doppler shifts and distortions of the line shapes comma can provide insight concerning the thermal-pressure structure of the anomalously hot outer layers of these stars and how these structural properties change with the ebb and flow of a magnetic activity cycle.