He did research at the University Observatory Munich's Southern Station on Mount Stromlo in Australia.
Peter van de Kamp invited him to the Sproul Observatory to be a visiting professor in 1969.
[3] Peter van de Kamp, Wulff's predecessor at Swarthmore, made claims since the 1960s of a planetary system around Barnard's Star.
After van de Kamp's retirement in 1972, the photographic plates made using the Sproul refractor telescope were shown to be flawed, affecting Van de Kamp's Barnard's Star claim as well as claims of planetary systems around other near-by stars made at the same time by staff astronomer Sarah Lippincott.
[4] Heintz retired from active teaching in 1998 but remained a frequent and popular guest at the college.