The observations were made with Hubble's infrared NICMOS camera. The infrared light from the presumed planets is not reflected light from the host stars but instead represents heat emitted by the giant worlds.

The subtle detections involved using a trick developed by other researchers. After taking the first image of a white dwarf and its surroundings, Hubble was rolled slightly in space and a second image was made. By comparing the two images, scattered light created by instrument imperfections can be removed, Debes explained. That way the star is reduced more closely to a point-like source. Remaining nearby points of light then emerge as either dim orbiting companions or background objects.