Flat-spectrum Radio Continuum Emission Associated with ɛ Eridani

We present Very Large Array observations at 33.0 GHz that detect emission coincident with ɛ Eridani to within 0.″07 (0.2 au at the distance of this star), with a positional accuracy of 0.″05. This result strongly supports the suggestion of previous authors that the quiescent centimeter emission comes from the star and not from a proposed giant exoplanet with a semimajor axis of ∼1.″0 (3.4 au). The centimeter emission is remarkably flat and is consistent with optically thin free-free emission. In particular, it can be modeled as a stellar wind with a mass-loss rate of the order of 6.6 × 10^-11 {M}_⊙ yr^-1, which is 3300 times the solar value, exceeding other estimates of this star’s wind. However, interpretation of the emission in terms of other thermal mechanisms like coronal free-free and gyroresonance emission cannot be discarded.