The phrase the “dog days of summer” is usually heard a lot this time of year, but have you ever thought about where it comes from?

It’s not named for our furry four-legged friends who tend to lay around in the heat, but it has its origins in the stars.

It’s all about the dog star in fact.

The ancient Greeks, Romans - and even Egyptians - all believed that when Sirius, the brightest star in the night sky was visible during the daytime, it was responsible for additional heat. When the sun and Sirius were out together, it made these summer days feel even hotter.

Sirius is in the constellation Canis Major and right about now, you can’t see it because it sits just below the constellation Orion and rises with the sun.

According to Greek mythology, Sirius was one of Orion’s hunting dogs. The ancient Greeks and Romans referred to this time of year as “dies caniculares” or days of the dog star.

The ancient Egyptians 5,000 years ago noticed that when Sirius started rising just before the sun again, it was when the annual flooding of the Nile would occur. By the 1500s, the English world used to call these same hot weeks “dog days.”

Currently, we refer to the dog days as the weeks between July 3- Aug. 11. The dates of the dog days have changed over the millennia, they are now several weeks later than they were during ancient times. Future generations thousands of years from now, will see the dog days even later in the year.