What is "albubather"

Abu Bakr al-Hassan ibn al-Khasib, also al-Khaseb, Albubather in Latin, was a Persian physician and astrologer of the 9th century.

He wrote in Persian and Arabic and is best known by his work De nativitatibus which was translated into Latin by Canonicus Salio in Padua 1218, and was also translated into Hebrew.