Muḥammad ibn ÿAbd AllÃÂh Nasá¹Âà «lus (; known as Nasá¹Âà «lus, but also referred to as Basá¹Âà «lus) was a 10th-century astronomer. He is known for making one of the oldest surviving astrolabes, dated 927/928, as well as of another partially preserved astrolabe that bears his signature, "Made by Nasá¹Âà «lus in the year 315" of hijra (925).
Very little is known about Nasá¹Âà «lus. His full name, based on a testimony given by a contemporary astronomer, Abu Sa'id al-Sijzi, indicates that he was a Muslim, but some modern historians have suggested that his foreign last name may indicate that he was Greek or Nestorian.