Optical microlensing surveys are restricted from detecting events near the Galactic plane and center , where the event rate is thought to be the highest , due to the high optical extinction of these fields .
In the near-infrared ( NIR ) , however , the lower extinction leads to a corresponding increase in event detections and is a primary driver for the wavelength coverage of the WFIRST microlensing survey .
During the 2015 and 2016 bulge observing seasons we conducted NIR microlensing surveys with UKIRT in conjunction with and in support of the Spitzer and Kepler microlensing campaigns .
Here we report on five highly extinguished ( A _ { H } = 0.81 - 1.97 ) , low-Galactic latitude ( -0.98 \leq b \leq - 0.36 ) microlensing events discovered from our 2016 survey .
Four of them were monitored with an hourly cadence by optical surveys but were not reported as discoveries , likely due to the high extinction .
Our UKIRT surveys and suggested future NIR surveys enable the first measurement of the microlensing event rate in the NIR .
This wavelength regime overlaps with the bandpass of the filter in which the WFIRST microlensing survey will conduct its highest-cadence observations , making this event rate derivation critically important for optimizing its yield .