  We report on SALT low resolution optical spectroscopy and optical/IR
photometry undertaken with other SAAO telescopes (MASTER-SAAO and IRSF) of the
kilonova AT 2017gfo (aka SSS17a) in the galaxy NGC4993 during the first 10 days
of discovery. This event has been identified as the first ever electromagnetic
counterpart of a gravitational wave event, namely GW170817, which was detected
by the LIGO and Virgo gravitational wave observatories. The event is likely due
to a merger of two neutron stars, resulting in a kilonova explosion. SALT was
the third telescope to obtain spectroscopy of AT 2017gfo and the first
spectrum, 1.2 d after the merger, is quite blue and shows some broad features,
but no identifiable spectral lines and becomes redder over time. We compare the
spectral and photometric evolution with recent kilonova simulations and
conclude that they are in qualitative agreement for post-merger wind models
with proton: nucleon ratios of $Y_e$ = 0.25$-$0.30. The blue colour of the
first spectrum is consistent with the lower opacity of the Lathanide-free
r-process elements in the ejecta. Differences between the models and
observations are likely due to the choice of system parameters combined with
the absence of atomic data for more elements in the ejecta models.
