  We present the results of photometric observations of active asteroid (6478)
Gault performed at heliocentric distances from 2.46 to 2.30 au and geocentric
distances from 1.79 to 1.42 au between January 15 and March 28, 2019.
Observations were carried out at the 2.5-m telescope of SAI MSU (CMO) on
January 15, 2019 and at the 1.3-m and 0.61-m telescopes (SPb) on February 6 and
March 28, 2019, respectively. The direct images of the asteroid were obtained
with the broad-band B, V and R filters. Comet-like structures were detected at
all observation dates. Colour maps were built and colour variations along the
tail for the observation made on January 15, 2019 were analyzed. The $Af\rho$
was calculated for the R filter, The evaluated value varies from 47 to 32 cm
for the period from January to the end of March, 2019. The rotational period of
the body is estimated from the light curve by different methods and is about
1.79 hr. Possible mechanisms of triggering Gault's activity are discussed.
