Detection of microwave emission from both components of the red dwarf binary EQ Pegasi

Abstract

The detection at 4.9 GHz of the late main sequence binary EQ Pegasi (dM3.5e + dM4.5e) with the VLA is reported. Both components were detected, as flux levels of 0.69 mJy and 0.4 mJy, respectively. Thermal gyroresonance emission from the quiescent coronae of these stars appears to explain observations of the authors, as it does those of Gary and Linsky (1981) for chi Ori and UV Ceti, provided coronal magnetic fields in excess of 300 gauss exist over a region that has a length scale of at least twice the radii of these stars. Support for this model is provided by the unlikelihood of both stars flaring simultaneously, and by the fact that the emission was confined to each star within the observational uncertainty of a few AU.