OGLE-2018-BLG-1428Lb: a Jupiter-mass planet beyond the snow line of a
  dwarf star
  We present the analysis of the microlensing event OGLE-2018-BLG-1428, which
has a short-duration ($\sim 1$ day) caustic-crossing anomaly. The event was
caused by a planetary lens system with planet/host mass ratio
$q=1.7\times10^{-3}$. Thanks to the detection of the caustic-crossing anomaly,
the finite source effect was well measured, but the microlens parallax was not
constrained due to the relatively short timescale ($t_{\rm E}=24$ days). From a
Bayesian analysis, we find that the host star is a dwarf star $M_{\rm
host}=0.43^{+0.33}_{-0.22} \ M_{\odot}$ at a distance $D_{\rm
L}=6.22^{+1.03}_{-1.51}\ {\rm kpc}$ and the planet is a Jovian-mass planet
$M_{\rm p}=0.77^{+0.77}_{-0.53} \ M_{\rm J}$ with a projected separation
$a_{\perp}=3.30^{+0.59}_{-0.83}\ {\rm au}$. The planet orbits beyond the snow
line of the host star. Considering the relative lens-source proper motion of
$\mu_{\rm rel} = 5.58 \pm 0.38\ \rm mas\ yr^{-1}$, the lens can be resolved by
adaptive optics with a 30m telescope in the future.
