Muḥammad ibn ʿAbd Allāh Nasṭūlus (Arabic: محمد بن عبد الله نسطولس; known as Nasṭūlus, but also referred to as Basṭūlus) 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 Nasṭūlus in the year 315" of hijra (925).Very little is known about Nasṭūlus. 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. Source: Wikipedia (en)