dipper@utastro.UUCP (Debbie Byrd) (08/15/85)
The star Sirius is now coming back to the sky before dawn. More on the return of the Dog Star -- after this. August 15: Return of the Dog Star Around this time every year, Sirius returns to the predawn sky. Sirius is the sky's brightest star. It's a white diamond of a star that glitters in the evening sky each winter. The star won't be visible in the evening sky for several more months. But, this month, you can see Sirius as comes back to the sky before dawn. Sirius is recognizable for being brighter than any other star -- though it may not look as bright when it's low in the sky as when it's higher up. Also, Sirius isn't as bright as the planet Venus -- now high in the east before dawn. Look for Sirius low in the east just before sunup. It'll be surprisingly bright for being so low in the sky -- piercing the haze on the horizon -- just south of where the sun will rise. Because you'll see it low in the sky, through great thicknesses of atmosphere, you might notice Sirius flashing different colors. Sirius was an important star to the early Egyptians, who called it "the Dog Star." Its annual reappearance in the east before the sun is known as its "heliacal rising." The heliacal rising of Sirius used to occur around the end of June -- about the same time that Egypt's Nile River staged is yearly flood. Thus, to the ancient Egyptians, the Dog Star's return appeared to bring the flood. The priests watched before dawn for the reappearance of the Dog Star each year -- and later founded their calendar on the momentous event. Script by Deborah Byrd. (c) Copyright 1984, 1985 McDonald Observatory, University of Texas at Austin
shanks@teneron.UUCP (Dave Shanks) (08/23/85)
In article <559@utastro.UUCP> dipper@utastro.UUCP (Debbie Byrd) writes: >Around this time every year, Sirius returns to the predawn sky. ... > The heliacal rising of Sirius used to occur >around the end of June -- about the same time that Egypt's Nile River >staged is yearly flood. Why has the heliacal rising of Sirius moved from early summer to its present date since the time of the Egyptians? Does it have something to do with the precession of Earth's axis? This is just idle curiosity. -- Dave Shanks ..!tektronix!reed!teneron!shanks Teneron Corp. 6700 SW 105th Suite 200 Beaverton, OR 97005 (503) 646-1599