Nabu-ri-man-nu (also spelled Nabu-rimanni; Greek sources called him Ναβουριανός, Nabourianos, Latin Naburianus) (fl. c. 6th – 3rd century BC) was a Chaldean astronomer and mathematician.
Classical and ancient cuneiform sources mention an astronomer with this name:
The following is an excerpt of a century of scholarship discussed in the sources referenced below.The meaning of tersitu is not known definitively. Already Franz Xaver Kugler proposed that tersitu can be interpreted as "table" here; in another context it seems to mean something like "tool", but in yet another the word refers to a blue enamel paste. P. Schnabel, in a series of papers (1923–1927), interpreted the phrase as an assignment of authorship. Based on this, he argued that Naburimannu developed the Babylonian System A of calculating Solar System ephemerides, and that Kidinnu later developed Babylonian System B. Otto E. Neugebauer has remained reserved to this conclusion and disputed Schnabel's further inferences about Naburimannu's life and work. The mathematician B.L. van der Waerden later (1963, 1968, 1974) concluded that System A was developed during the reign of Darius I (521–485 BC). System A, which uses step functions, appears to be somewhat more primitive than System B, which uses zigzag linear functions, although System A is more consistent than System B. While it thus appears that System A preceded System B, both systems remained in use at least until the 1st century BC.
The earliest preserved System A clay tablets (BM 36651, 36719, 37032, 37053) calculate an ephemeris for the planet Mercury from 424 to 401 BC. The oldest preserved lunar tablets date from 306 BC in the Hellenistic period. If Naburimannu was the originator of System A, then we can on that basis place him in Babylonia sometime between the Persian and Macedonian conquests.