During the reign of Amenhotep I, the Egyptians recorded an astronomical event. This was the star Sothis appearing above the horizon at dawn. This is called a heliacal rising. Modern scientists believe that Sothis is the star that we call Sirius. If this observation was made at Thebes, it took place in 1517 BC. From this date, the date of Amenhotep's death, and Thutmose's coronation can be calculated to 1506 BC. But a few historians believe that the observations were made at either Heliopolis or Memphis. This would mean that Thutmose would have been crowned in 1526 BC.