What property of a reflecting telescope determines its light-gathering (or light-collecting) power? O primary mirror radius of curvature diameter of mirror longitude of telescope type of telescope dome The Hobby-Eberly Telescope has a diameter of 9.2 m. The WIYN Observatory Telescope has a 3.5 m diameter. How many times larger is the light-gathering power (LGP) of the Hobby-Eberly Telescope compared to the WIYN Observatory Telescope? KAREN Hobby-Eberly Telescope The Hobby-Eberly Telescope is a 9.2 m telescope at McDonald Observatory. of 24 > ARATAI The Hobby-Eberly Telescope is a 9.2 m telescope at McDonald Observatory. LGP of Hobby-Eberly Telescope: Hobby-Eberly Telescope Image credits: Marty Harris/McDonald Observatory/UT Austin x LGP of WIYN Observatory Telescope