Italian astronomer of the fifteenth and sixteenth centuries. In 1490-2 he was in Lucca where he wrote an elegy on the death of Jehiel of Pisa. In 1492 Chalfan was in Naples, where he studied astronomy. Chalfan was the author (in 1494) of “?a’ame Mi?wot,” containing explanatory notes on the Alfonsine Tables, still extant in manuscripts in Naples and Parma. These notes by Chalfan were translated by historian David Gans when he visited and participated in the astronomical research conducted by Tycho Brahe and his assistant Johannes Kepler at the imperial observatory in the Benátky summer palace of Rudolf II in 1600. Gans named one of his sons Abba Mari, making it very likely that Gans was married to a descendant of Chalfan.
https://www.geni.com/people/Rabbi-Abba-Chalfan-the-astronomer/6000000000348850434
