Exploring the X-ray emission of G-type giants spun up by accretion

Fastrotation (v sin i of over 20 km/s) is rare among yellow (G2K1) giants,restricted to tidallysynchronized binary components and the handful of FK Comclass single stars. Such stars have Xray luminosities and plasma temperaturesamong the highest of known coronal sources. A number of yellow giants with v 100 km/s have been found as companions to hot subdwarfs. These stars have beenspun up by accretion of material from the companion during its AGB phase. Wefind the Xray emission of the opticallybrightest example to be an order ofmagnitude lower than that of FK Com stars. We propose to observe the only twobright comparable systems to discover whether such a surprisingly inefficientmagnetic dynamo is a general outcome of accretive spinup. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]