Flat Spectrum Radio Continuum Emission Associated with $epsilon$ Eridani


Abstract in English

We present Very Large Array observations at 33.0 GHz that detect emission coincident with $epsilon$ Eridani to within $0rlap.{}07$ (0.2 AU at the distance of this star), with a positional accuracy of $0rlap.{}05$. 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 semi-major axis of $sim1rlap.{}0$ (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 $6.6 times 10^{-11}~ M_odot ~yr^{-1}$, which is 3,300 times the solar value, exceeding other estimates of this stars wind. However, interpretation of the emission in terms of other thermal mechanisms like coronal free-free and gyroresonance emission cannot be discarded.

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