  We present a search for continuous gravitational waves emitted by neutron
stars in binary systems conducted on data from the early third observing run of
the Advanced LIGO and Advanced Virgo detectors using the semicoherent,
GPU-accelerated, BinarySkyHough pipeline. The search analyzes the most
sensitive frequency band of the LIGO detectors, 50 - 300 Hz. Binary orbital
parameters are split into four regions, comprising orbital periods of 3 - 45
days and projected semimajor axes of 2 - 40 light-seconds. No detections are
reported. We estimate the sensitivity of the search using simulated continuous
wave signals, achieving the most sensitive results to date across the analyzed
parameter space.
