Wednesday, August 10, 2011
The Dog Days of Summer
The Dog Days of Summer are the hottest, most sweltering days of the year. Depending on your location, they run for about a month between early July to the beginning of September in the northern hemisphere, and from January to March in the southern hemisphere.
The term "Dog Days" refers to the days when Sirius, the Dog Star, rises with the sun.
The ancient Egyptians associated Horus, the dog-headed god, with Sirius, the brightest star in the constellation Canis Major (The Greater Dog) and the brightest star in the night sky. During this time, Sirius rose at dawn during the most blistering part of summer. The Egyptians, Greeks and Romans believed the bright Sirius, so close to the sun, added its radiation to the sun's, increasing the season's already fierce heat.
To the ancients, these sultry days, when rainfall is at its lowest and temperature its highest, was an evil time, causing suffering and disease in man and beast. Food spoiled, dogs went mad and all creatures languished in the stifling atmosphere.
Due to the precession of the equinoxes (the change in the earth's orientation to the night sky as our globe revolves around the galactic center), Sirius no longer rises at daybreak on the same dates as it did for the ancient Mediterranean civilizations. In the Roman era, the Dog Days ran from July 24 through August 24. Today, the Dog Days run from July 3 to August 11, according to The Old Farmers' Almanac, although many European cultures adhere to the original dates.
So, if you're awake before dawn during the peak of summer, take a look at the eastern sky. That bright star near the horizon is Sirius, heralding the Dog Days of Summer.
Thank you all,
The picture, from Wikipedia, is of Canis Major. Sirius marks the dog's nose.