Panel (a) 5^∘ × 5^∘ IRIS 60 μm far-infrared image of the surroundings of T Pyxidis, with the nova’s location indicated with a white star. Panel (b) Same as panel (a) but with a boundary of the apparent cavity outlined with a dashed line for guidance. Panel (c) Arbitrary surface brightness radial profile of the surroundings of T Pyxidis from annular photometry (see text). The largest extent of the apparent cavity at 107 pc is indicated with the dashed line.