1998A&A...331..596B

The binary system UV Cet A and B has been observed with the VLBA/VLA at 3.6cm wavelength. Both dMe stars have been detected. The stronger, steady radio emitter of the two, UV Cet B, is resolved into at least two spatial components. Their relative intensities change during the 6.3 hours of observing time. One of the components is more stable and resolved, the other is possibly unresolved. The resolved component has a half-power diameter of 2.4x10¹⁰cm, exceeding the size of the stellar photosphere. The separation of the two components of UV Cet B is 4.4(±0.4)x10¹⁰cm or 4-5 stellar radii. The alignment of the two components is along the axis of the binary orbit and thus parallel and very likely close to the stellar rotation axis. The apparent trapping of the gyrosynchrotron emitting energetic electrons requires large coronal loops extending to several stellar radii. At the more variable source a magnetic field between 15 and 130 G is derived.