Lupitus of Barcelona, identified with a Christian archdeacon called Sunifred, was an astronomer in late 10th century Barcelona, then part of the Marca Hispanica between Islamic Al-Andalus and Christian France (in 985 changing from Christian back into Muslim hands by the conquest of Al-Mansur).
Lupitus was instrumental in the transfer of Arabic mathematics, including the astrolabe and the Hindu-Arabic numeral system to Christian Europe. Gerbert of Aurillac in a letter of 984 asks Lupitus for a translation of an Arabic astronomical treatise, the Sententiae astrolabii.
References
Lupitus of Barcelona Wikipedia(Text) CC BY-SA