By now everyone is well aware that summer is here, with the onset of really hot temperatures. Some people love it, some people hate it. But it’s a fact of life here where we live.
You’ve probably often heard the term “Dog Days of Summer” used at this time of year. But do you know what that means, and where it came from? If not, you’re in luck, because we’re going to talk about these hot summer days.
The term “Dog Days” has been credited to the ancient Romans, who coined the term caniculares dies (days of the dogs) for the constellation Canis Major, of which the star Sirius resides. Sirius is commonly referred to as “The Dog Star” and is the brightest star in the night sky. The Romans believed that since Sirius rose & set at the same time as the sun, the added heat from the star caused the sweltering temperatures on Earth.
Likewise, the ancient Egyptians noticed that when Sirius rose just before the sun, the Nile river flooded. The Egyptians are the ones who actually nicknamed Sirius the “Dog Star” after their god Osirus (whose head was pictured as a dog).
In recent times, people thought that the apparent laziness of dogs during the hottest days, as they laid around and periods of inactivity were the source of the “dog days” term.
Typically the Dog Days last from July 3rd until August 11th, the hottest times of the summer in the northern hemisphere. We now know that it is not the “added heat” from the star Sirius, but from the tilt of the Earth’s axis. And what’s more, we know something else the ancients didn’t know – Sirius has a companion. Sirius B is a white dwarf star, not visible without telescopic aide.
But who knows? If the ancient Romans and Egyptians knew that, it might have given more credence to their explanation of the “Dog Days” of summer.