the two telescopes, ogle and spitzer, discovered the planet through gravitational microlensing. this is done by observing when the star passes between earth and another star. the distance at which the star is seen allows us to observe gravity bending the light and the change of brightness shows the existence of the star. if there is a planet orbiting the star, then the astronomer will also see the same thing twice, which helped astronomers discover ogle-2014-blg-0124lb.