  We report photometric observations in Johnson UBV bands of the short term
variability of Mira. The amplitude detected is 0.16 mag in B band. Adopting
interstellar extinction E(B-V)=0, we find for the flickering source colour
B-V=1.3, temperature T=3700 K, and radius R=0.77 Rsun. The colour of the
flickering source is considerably redder than the average B-V colour of the
cataclysmic variables.
