  We report on the discovery of Swift J011511.0-725611, a rare Be X-ray binary
system (BeXRB) with a White Dwarf (WD) compact object, in the Small Magellanic
Cloud (SMC) by S-CUBED, a weekly X-ray/UV survey of the SMC by the Neil Gehrels
Swift Observatory. Observations show an approximately 3 month outburst from
Swift J011511.0-725611, the first detected by S-CUBED since it began in 2016
June. Swift J011511.0-725611 shows super-soft X-ray emission, indicative of a
White Dwarf compact object, which is further strengthened by the presence of an
0.871 keV edge, commonly attributed to O viii K-edge in the WD atmosphere.
Spectroscopy by SALT confirms the Be nature of the companion star, and long
term light-curve by OGLE finds both the signature of a circumstellar disk in
the system at outburst time, and the presence of a 17.4 day periodicity, likely
the orbital period of the system. Swift J011511.0-725611 is suggested to be
undergoing a Type-II outburst, similar to the previously reported SMC Be White
Dwarf binary (BeWD), Swift J004427.3-734801. It is likely that the rarity of
known BeWD is in part due to the difficulty in detecting such outbursts due to
both their rarity, and their relative faintness compared to outbursts in
Neutron Star BeXRBs.
