  We report on radio timing and multiwavelength observations of the 4.66 ms
redback pulsar J1048+2339, which was discovered in an Arecibo search targeting
the Fermi-LAT source 3FGLJ1048.6+2338. Two years of timing allowed us to derive
precise astrometric and orbital parameters for the pulsar. PSR J1048+2339 is in
a 6-hour binary, and exhibits radio eclipses over half the orbital period and
rapid orbital period variations. The companion has a minimum mass of 0.3 solar
masses, and we have identified a $V \sim 20$ variable optical counterpart in
data from several surveys. The phasing of its $\sim 1$~mag modulation at the
orbital period suggests highly efficient and asymmetric heating by the pulsar
wind, which may be due to an intrabinary shock that is distorted near the
companion, or to the companion's magnetic field channeling the pulsar wind to
specific locations on its surface. We also present gamma-ray spectral analysis
of the source and preliminary results from searches for gamma-ray pulsations
using the radio ephemeris.
