Wednesday, July 29, 2009

The Dog Days of Summer Are Upon Us

by Milky Way Maid

What are the 'dog days' of summer? We use the phrase so often and most of us have no idea where it comes from. Many of us think they got that name because dogs get so hot in the heat of summer and just lie around panting.

The name comes from Sirius, the dog star, which in Roman times was conjunct the Sun from about July 3 to August 11 (dates per Old Farmers' Almanac). They believed that the heat of the bright star Sirius was added to that of the Sun, leading to the extreme temperatures. They dubbed those days “caniculares dies” or “days of the dog star”. Dog star in Latin is caniculares.

Dogs also figure in the lore of 'dog days' because the Romans often sacrificed a brown dog at the beginning of the phase to appease Sirius. (I think you can stop worrying that your beloved Fido will be snatched by errant Romans, but you can keep your dog indoors just to play it safe. Also, I am pretty sure you can substitute hot dogs on the grill instead, and Sirius will be just as happy.) BTW August 16 is the feast day of St. Roch, who is the patron saint of dogs.

Nowadays, due to precession, Sirius does not even conjoin the sun on the Roman dog days. Now the conjunction is generally from August 4 till Sept. 12, a period of 40 days. This varies with the latitude and the climate, of course. If you need to know more specifics, then consult either an ephemeris or dig up an ancient Egyptian astrologer.

One poem that has survived the ages, which claims to foretell the future from the weather during 'dog days' goes like this:
“Dog days bright and clear, indicate a happy year. But when accompanied by rain, for better times our hopes are vain.” I have no idea if this is an economic forecast or a farming forecast, so don't play the stock market based on fair or wet weather during dog days.

And lastly, the heliacal rising of Sirius at the beginning of ancient dog days was the signal to the Egyptians that the annual flooding of the Nile River was about to begin. A whole civilization was built on the fertile soil brought by this phenomenon. That's pretty amazing.

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