Different temperature indicators: T_eq, T_av and T_max of amorphous carbonaceous nano-grains (mostly aromatic), taken from the THEMIS grain model, versus distance from the star. Different grain sizes are considered: 0.4, 0.7, 1.5 and 10 nm. The temperature indicators correspond to the equilibrium temperature, average temperature and maximum temperature, respectively. The red dotted line corresponds to ‘model required’ temperature of 1700 K. No sublimation or grain destruction was considered here.