STRONG RADIO FLARING PERIOD IN UX ARIETIS

In January 1993 we observed the RS CVn-type binary system UX Ari at 6 cm using the 32 m radiotelescope of Note, with a temporal coverage of about 12 hours per day. The source was found to be in a very active pe riod, with a continuous series of radio flares of flux densities up to 350 mJy. The analysis of the data shows that the radio emission consi sts of two different components: a continuous series of strong radio f lares and an orbital phase dependent component, with a minimum of emis sion around phase Phi = 0.5. The amplitude of the radio flares and the ir time of occurrence do not depend on the orbital phase, suggesting t hat the region where they originate is always visible from Earth. A br ight and stable active region, localized in the hemisphere of the K st ar not visible from the G star, seems to account for the orbital phase dependence of the radio emission.