First Resolved Images of the Mira AB Symbiotic Binary at Centimeter Wavelengths

We report the first spatially resolved radio continuum measurements of the Mira AB symbiotic binary system, based on observations obtained with the Very Large Array (VLA). This is the first time that a symbiotic binary has been resolved unambiguously at centimeter wavelengths. We describe the results of VLA monitoring of both stars over a 10 month period, together with constraints on their individual spectral energy distributions, variability, and radio emission mechanisms. The emission from Mira A is consistent with originating from a radio photosphere, while the emission from Mira B appears best explained as free-free emission from an ionized circumstellar region ~(1-10)×10¹³ cm in radius.