It’s an expression that I’ve always associated with the hot, sultry final days of summer.
You know – the kind of steamy, humid weather that could make a dog either lazy or likely to go mad.
The private high school that I attended sixty years ago thought it important to expose its students, for a full five years, to a classical education – in other words, a little bit of everything.
We studied Latin and French, English grammar and English literature, physics history, geography and chemistry, algebra, geometry and trigonometry.
But not astronomy.
The little that I knew about astronomy came from my time in the Royal Canadian Sea Cadets. They taught me that Sirius is the brightest star in our planet’s night sky. The name Sirius in Greek, fittingly enough, means “glowing.”
Sirius is also known as the “Dog Star.” It gets this nickname because it forms part of the constellation Canis Major, which my five years of Latin tells me translates as the “greater dog.”
A little basic astronomy in high school might have provided some clarity about the origin of the expression, “the dog days of summer.”
The expression was known to the scholars who studied the skies as far back as Greek and Roman times. They knew that, from July 3 through August 11, Sirius rose and set in the same part of the sky as the sun.
Most particularly, on July 23, Sirius rose in conjunction with the sun. The star was so bright that the Romans believed that it was emitting heat – adding to the hot and sultry weather. The Romans called this time “canis caniculares” – the dog days.
The expression came to refer to the twenty days both before and after the July 23 date on which Sirius and the sun shared the same location in the heavens – in other words, the period between July 3 and August 11.
For Polynesians in the southern hemisphere, Sirius played an important role in celestial navigation.
If you know as little about astronomy as I do, but want to see Sirius for yourself, here’s how. (Warning: it means getting up before dawn)
First, you have to locate Orion’s Belt. Look south to southeast. You’ll find this short, straight row of three medium-bright stars. Just draw a line through Orion’s Belt and extend that line toward the horizon.
You should quickly spot Sirius, the sky’s brightest star.
The dog days of summer may be over for another year but, as Paul Harvey used to say on his old radio show, “and now you know the rest of the story.”