I never associated the "dog days of summer" with astronomy....
I merely thought the dog days were towards the end of the summer when it was exceedingly hot and dry day in and day out....ready for fall to arrive...
I never associated the “dog days of summer” with astronomy...
The ancients thought that Sirius being the brightest star (except of course the sun) added its heat to the sun during the summer when it’s on the same side of the sky as the sun. That is, you see it in winter when it’s on the opposite side of the sky as the sun.