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We use the Very Large Array (VLA) in the A configuration with the Pie Town(PT) Very Long Baseline Array (VLBA) antenna to spatially resolve the extendedatmosphere of Betelgeuse over multiple epochs at 0.7, 1.3, 2.0, 3.5, and 6.1cm. The extended atmosphere deviates from circular symmetry at all wavelengthswhile at some epochs we find possible evidence for small pockets of gassignificantly cooler than the mean global temperature. We find no evidence forthe recently reported e-MERLIN radio hotspots in any of our multi-epoch VLA/PTdata, despite having sufficient spatial resolution and sensitivity at shortwavelengths, and conclude that these radio hotspots are most likelyinterferometric artefacts. The mean gas temperature of the extended atmospherehas a typical value of 3000 K at 2 $R_{\star}$ and decreases to 1800 K at 6$R_{\star}$, in broad agreement with the findings of the single epoch studyfrom Lim et al. (1998). The overall temperature profile of the extendedatmosphere between $2 R_{\star} \lesssim r \lesssim 6 R_{\star}$ can bedescribed by a power law of the form $T_{\mathrm{gas}}(r) \propto r^{-0.6}$,with temporal variability of a few 100 K evident at some epochs. Finally, wepresent over 12 years of V band photometry, part of which overlaps ourmulti-epoch radio data. We find a correlation between the fractional fluxdensity variability at V band with most radio wavelengths. This correlation islikely due to shock waves induced by stellar pulsations, which heat the inneratmosphere and ionize the more extended atmosphere through radiative means.Stellar pulsations may play an important role in exciting Betelgeuse's extendedatmosphere.

Temporal Evolution of the Size and Temperature of Betelgeuse's Extended Atmosphere