  We report the discovery of the optical counterpart to GRB 980326. Its rapid
optical decay can be characterized by a power law with exponent -2.10 +/- 0.13
and a constant underlying source at R_c=25.5 +/- 0.5. Its optical colours 2.1
days after the burst imply a spectral slope of -0.66 +/- 0.70. The gamma-ray
spectrum as observed with BATSE shows that it is among the 4% softest bursts
ever recorded. We argue that the rapid optical decay may be a reason for the
non-detection of some low-energy afterglows of GRBs.

Astrophysics