  We carried out I, R, V and B photometric observations of the neutron star
X-ray binary RXTE J2123-058 shortly after the end of the X-ray outburst in
mid-1998. We adopt the low mass binary model to interpret our observations.
After folding our data on the 0.24821-d orbital period, and correcting for the
steady brightness decline following the outburst, we observe sinusoidal
oscillations with hints of ellipsoidal modulations which became progressively
more evident. Our data also show that the decline in brightness was faster in
the V band than in the R and I bands. This suggests both the cooling of an
irradiation-heated secondary star and the fading of an accretion disc over the
nights of our observations.
