Mean gas temperature profile of Betelgeuse’s extended atmosphere revealed by multi-wavelength spatially resolved VLA and VLA/PT observations spanning 1996−2004. The red filled circles are from the work of L+98 while the dotted line is the predicted gas temperature profile from the semi-empirical model of Harper et al. (2001). All other data points are from this work. The error bars represent the ±1σ_rms level, except the 0.7 cm error bars of L+98 which include a ±20% uncertainty in the absolute flux density. The vertical and horizontal dashed lines represent the photospheric radius of 21.24 mas and the photospheric effective temperature of 3690 K, respectively (Ohnaka et al. 2011).