  We investigate a charge asymmetry in $t \bar t \gamma$ production at the LHC
that provides complementary information to the measured asymmetries in $t \bar
t$ production. We estimate the experimental uncertainty in its measurement at
the LHC with 8 and 14 TeV. For new physics models that simultaneously reproduce
the asymmetry excess in $t \bar t$ at the Tevatron and the SM-like asymmetry at
the LHC, the measurement in $t \bar t \gamma$ at the LHC could exhibit
significant deviations with respect to the SM prediction.
