The "Demon Star", which flickers and dims in the vast universe on a regular schedule as it is eclipsed by another star, may have been recorded by ancient Egyptians. Scientists are studying calendars kept by the superstitious civilization and are trying to determine for certain that the demon star is what they're looking at. If it is, it will be the earliest known record of such a star--more than 3,000 years earlier than previously thought.
The main purpose for the calendars, we believe, was to keep track of unlucky and fortuitous days, as well as to mark mythological events. As far as researchers can glean, the full moon was considered extremely good luck; the new moon, bad. Now, evidence suggests the Egyptians may have been tracking the demon star, which is eclipsed about every 3 days by a larger star within the Perseus constellation. The demon star goes by another name--Algol--and is one of the "eyes" in Medusa's constellation-formed head.
This is where Batman comes in; Algol is derived from the Arabic phrase ra's al-ghul, or "the demon's head". And if you know your Batman history, Ra's Al Ghul is the name of one of the Dark Knight's mortal enemies, played by Ken Watanabe in "Batman Begins".
The star dims by about a factor of ten when it is eclipsed and is visible to the human eye. It is associated on the Egyptian calendar with good days because of its connection with the god Horus.
"The eclipse seems to be linked with the lucky days, because it represents the pacification of the Eye of Horus," Sebastian Porceddu, an astronomer and Egyptologist at the University of Helsinki, said. "A bright Eye of Horus meant it is raging and a threat to mankind."
Researchers have also found a slight discrepancy between the time Algol was being eclipsed in ancient days and in the present; apparently, matter has begun to shift from Algol to the bigger star, causing the eclipse to take longer. That hasn't been proven for sure as yet, but if it's true, the discovery could certainly change what we know about eclipsing binaries and their orbits.