K2 Campaign 9 ( K2 C9 ) was the first space-based microlensing parallax survey capable of measuring microlensing parallaxes of free-floating planet candidate microlensing events .
Simultaneous to K2 C9 observations we conducted the K2 C9 Canada-France-Hawaii Telescope Multi-Color Microlensing Survey ( K2 C9-CFHT MCMS ) in order to measure the colors of microlensing source stars to improve the accuracy of K2 C9 ’ s parallax measurements .
We describe the difference imaging photometry analysis of the K2 C9-CFHT MCMS observations , and present the project ’ s first data release .
This includes instrumental difference flux lightcurves of { 217 } microlensing events identified by other microlensing surveys , reference image photometry calibrated to PanSTARRS data release 1 photometry , and tools to convert between instrumental and calibrated flux scales .
We derive accurate analytic transformations between the PanSTARRS bandpasses and the Kepler bandpass , as well as angular diameter-color relations in the PanSTARRS bandpasses .
To demonstrate the use of our data set , we analyze ground-based and K2 data of a short timescale microlensing event , OGLE-2016-BLG-0795 .
We find the event has a timescale t _ { E } = 4.5 \pm 0.1 days and microlens parallax \pi _ { E } = 0.12 \pm 0.03 or 0.97 \pm 0.04 , subject to the standard satellite parallax degeneracy .
We argue that the smaller value of the parallax is more likely , which implies that the lens is likely a stellar-mass object in the Galactic bulge as opposed to a super-Jupiter mass object in the Galactic disk .