The Assyrian eclipse, also known as Bur-Sagale (Bur-Saggile, Pur-Sagale or Par-Sagale) eclipse, was a solar eclipse that occurred on 15 June 763 BC (proleptic Julian calendar). It was recorded in Assyrian eponym lists, most likely in the ninth year of the reign of king Ashur-dan III. The entry is short and reads:
- Bur-Sagale of Guzana, revolt in the city of Assur. In the month Simanu an eclipse of the sun took place.
The phrase used — shamash ("the sun") akallu ("bent", "twisted", "crooked", "distorted", "obscured") — has been interpreted since the mid-nineteenth century as a reference to a solar eclipse. In 1867, Henry Rawlinson decided that the most likely match was the nearly total eclipse of 15 June 763 BC, and this date has been widely accepted ever since.
Historians consider this record a crucial point of reference for providing exact dates of Assyrian chronology before the seventh century BC. However, the original record is lacking details of the observation. It may have been observed anywhere in Assyria, not necessarily in Assur or Nineveh.
Apparently there has been some controversy on whether the eclipse of 24 June 791 BC is not a better candidate than 15 June 763 BC for the possible eclipse mentioned in the record (see graph). This depends on when the Assyrians started their luni-solar year.
The mainstream view is that the beginning of the Babylonian year was not determined by observing the equinox, but by observing the appearance of certain constellations.
A detailed examination of 101 New Year dates between 748 and 539 BC shows that the dates of the New Year shifted. In the eighth century it often began before the vernal equinox. The commonly-held belief is that "the aimed-for beginning of the Babylonian year in the eighth century fell about two weeks before the equinox." During the reign of Nabopolassar (625-605 BC) there was a shift to about ten days after the equinox, although there still were years when the New Year began before the equinox.
In summary, the situation in Babylonia before the last third of the eighth century seems to agree with the statement in MUL.APIN (Hunger and Pingree 1989) that the vernal equinox fell on Nisan 15. Probably around 730 the aimed-for beginning of the Babylonian year was shifted some two weeks upwards in relation to the solar year, so the average New Year's Day fell shortly before the vernal equinox. This holds true for the entire seventh century. Only around 600 did a second shift occur, which pushed the average beginning of the year to about two weeks after the vernal equinox (figure 4B).
That the Eponym Canon solar eclipse is identified correctly with the total solar eclipse that occurred in 763 BC, is confirmed by other astronomical observations from the same period.
- Rawlinson, Henry Creswicke, "The Assyrian Canon Verified by the Record of a Solar Eclipse, B.C. 763", The Athenaeum: Journal of Literature, Science and the Fine Arts, nr. 2064, 660-661 [18 May 1867].
- Schaumberger, Johann 3. Ergänzungsheft zum Ersten und Zweiten Buch von Franz Xaver Kugler, Sterndienst and Sternkunde in Babel, Münster in Westfalen, Verlag der Aschendorffschen Verlagsbuchhandlung, 1935, pp. 340-344 ; Hermann Hunger, "A Scheme for Intercalary Months from Babylonia," in Wiener Zeitschrift für die Kunde des Morgenlandes,67. Band, Wien 1975, pp. 21-28. Cf. also Hermann Hunger's article in Reallexikon der Assyriologie, Band 10, Walter de Gruyter, Berlin, New York, 2005, p. 592.
- Gerber, Manuel "A Common Source for the Late Babylonian Chronicles Dealing with the Eighth and Seventh Centuries," Journal of the American Oriental Society, Vol. 120:4, October–December 2000, p. 559
- Hermann Hunger, "Zur Datierung der neuassyrischen Eponymenliste," Altorientalische Forschungen, Vol. 35:2, 2008, pp. 323-325. An English translation is available on the web: 
- Path map of eclipses 780 BCE - 761 BCE (NASA) - Includes total eclipse of June 15, 763 BC (labeled -0762 June 15)
- Path map of eclipses 800 BCE - 781 BCE (NASA) - Includes annular eclipse of June 24, 791 BC (labeled -0790 June 24)
- Five Millennium (-1999 to +3000) Canon of Solar Eclipses Database – maps the visibility of the total solar eclipse of June 15, 763 BC.
- Five Millennium (-1999 to +3000) Canon of Solar Eclipses Database – maps the visibility of the annular solar eclipse of June 24, 791 BC.