Correlations Between the Radio Emission and Starspot Distribution of UX Arietis

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Session 85 -- Interacting Binaries: ``Normal'' Stars
Display presentation, Friday, January 14, 9:30-6:45, Salons I/II Room (Crystal Gateway)

[85.05] Correlations Between the Radio Emission and Starspot Distribution of UX Arietis

A. Quirrenbach (MPIfEP), N.M. Elias II (USNO), A. Witzel, C. Naundorf, R. Wegner (MPIfR), E.F. Guinan, G.P. McCook (Villanova U.)

We have obtained three weeks of UX Arietis C-band observations with a VLA subarray. The temporal coverage during the program was moderately dense, about 3 scans day$^{-1}$. We also have UX Ari visible-band light curves obtained immediately after the radio observations. A few days after the beginning of the cm program, UX Ari began a period of strong radio flaring which lasted for at least two weeks. All the radio fluxes were statistically significant during this episode, but the largest values occurred close to 0.0 phase (the cool, spotted star between the observer and the hot star). These results are confirmed by later observations from another group. The visible-band light curves of UX Ari also indicated that the maximum starspot visibility occured near 0.0 phase. The best model for the radio emission is a relatively long period of flare activity (arising from or related to the starspots) modulated by stellar eclipses. Also, all the observations interpreted together strongly suggest that the flaring cm emission of UX Ari is intimately related to the distribution of photospheric starspot groups.

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