from teaching at Case Western in 1986. He became a Professor Emeritus, and in 1990 and 1991 continued to do research and remained active in the astronomy department. As a Professor Emeritus, Bidelman continued with the Henry Draper Reclassification project with Houk and the Michigan Spectral Survey and compiled identification of stars in the IRAS Low-Resolution Spectral Catalogue. Bidelman became interested in the Star of Bethlehem and argued it was involved planetary conjunctions. In 1991, Bidelman used astronomical tables by Bryant Tuckerman and Jean Meeus to investigate Roger Sinnott's suggestion that two close conjunctions of Venus and Jupiter on the morning of August 12, 3 BC, and the evening of June 17, 2 BC, could explain the Star of Bethlehem. He found that for these two planets, an easily observable morning conjunction is "invariably followed" by an evening conjunction approximately ten months later whenever the morning conjunction has an elongation of at least 19°. Bidelman found 28 such pairs of Venus-Jupiter conjunctions in the ~100 years before the birth of Christ, although the 3 and 2 BC conjunctions appeared closer together. Bidelman noted that John Mosley has shown the August 3 BC morning conjunction was ~4.3 arcminutes, and the June 2 BC evening conjunction was an "extremely close" 0.5 arcminutes, and Bidelman considered some historical events to determine the date of Christ's birth, and noted these conjunctions took place in Leo, a constellation associated with Judaism and the Tribe of Judah. Bidelman suggested the conjunctions in 3 and 2 BC are a plausible explanation for the Star of Bethlehem. In a brief 1991 Newsweek on Air interview about the Star of Bethlehem, when asked when and why he became interested in the topic, Bidelman said he had always been an astronomer, and it is of astronomical interest. When asked whether he thought his theory demystified Christmas, Bidelman replied: In 1992, almost 50 years after his thesis paper, Bidelman stated On revient toujours à ses premières amours ("One always returns to his first loves") when he returned to the topic of his dissertation in 1992 and he considered it "perhaps worth mentioning" that two stars seen then had completely changed their spectral appearance. In 1993, Bidelman provided data on 177 known and possible asymptotic giant branch stars, saying he was confident many would "prove to be interesting and important. Unfortunately, I don't know which ones!" Bidelman's list of high Strömgren c1