1998A&A...330.1060T

In January 1993 we observed the RS CVn-type binary system UX Ari at 6cm using the 32m radiotelescope of Noto, with a temporal coverage of about 12 hours per day. The source was found to be in a very active period, with a continuous series of radio flares of flux densities up to 350mJy. The analysis of the data shows that the radio emission consists of two different components: a continuous series of strong radio flares and an orbital phase dependent component, with a minimum of emission around phase {PHI}=0.5. The amplitude of the radio flares and their time of occurrence do not depend on the orbital phase, suggesting that the region where they originate is always visible from Earth. A bright and stable active region, localized in the hemisphere of the K star not visible from the G star, seems to account for the orbital phase dependence of the radio emission.