Top: images of the Tycho SNR environment at the nine Planck frequencies (Table 1), increasing from 30 GHz at top left to 857 GHz at bottom right. Each image is 100′ on a side , with galactic coordinate orientation. Bottom: microwave SED of Tycho. Filled circles are Planck measurements from this paper, with 3σ error bars. The open symbol at 1 GHz is from the Green catalogue, and the dashed line emanating from it is a power law with spectral index from the Green catalogue. Open diamonds are a 10.7 GHz measurement from Klein et al. (1979) and Herschel flux density from Gomez et al. (2012). The dotted lines are a revised synchrotron power law with spectral index α = 0.6 at low frequency, based on the radio including 10.7 GHz and the Planck 30–143 GHz flux densities, and a modified blackbody with emissivity index β = 1 and temperature 21 K at high frequency, based on the Herschel data. Downward arrows are upper limits (99.5% confidence) to the flux density from high-frequency Planck data. The solid line is a combination of the synchrotron and dust models.