The correspondence, manuscripts, notes, speeches, documents, and related printed materials of Hellman, reflecting her specialty as an historian of 16th and 17th century astronomers and astronomy as well as ancient, medieval, and Renaissance science. Included in her professional correspondence are numerous letters from George Sarton and Lynn Thorndike. College records, class materials and class notes document the development of her academic career beginning with her undergraduate career at Vassar. Numerous lecture notes, class notes and working papers reflect her teaching, research and lectures at New York University, Cornell, the Columbia University Renaissance Seminar, and her active participation in professional organizations such as the History of Science Society. Of particular interest are eight boxes of notes and related printed materials concerning astronomy, astronomers, and the history of science.