Midsommar Most Heat Moon
The dog days. Maybe not yet as hot as this mosaic portrays, certainly not here on Shadow Mountain, though Tucson and Phoenix… Friend Tom Crane sent me a link to this Updraft post about the dog days. I miss having an erudite blog like Updraft keeping me alert about weather. Weather5280 is the closest I’ve found. It’s good on weather, but it doesn’t go off into sidebars like explaining the days after the heliacal rising of Sirius. Heliacal? What’s that you might ask? Turns out heliacal is the first appearance of a star after a long absence. The dog days begin with the return of the brightest star in the night sky, Sirius. Or, at least they used to.
The Romans believed that the dog days were so hot that they made dog’s rabid. Sirius is the major star in the constellation, Canis Major, the Great Dog, but the Romans didn’t originate linking the rising of Sirius with heat. That belongs to the Greeks. They named the star “Seirios, Greek for “sparking” (referring to its near-constant twinkling), “fiery,” or “scorching,”” According to this page on Sky and Telescope, the Greeks believed its -1.46 magnitude intensified the already hot days of a Mediterranean summer.
Neither the Greeks nor the Romans, however, were the first ancient civilization to highlight the dog star. The Egyptians began the New Year when Sirius returned to the night sky because it corresponded with the flooding of the Nile, a seasonal nourishing of the fields that made Egyptian civilization flourish. Their calendar though, because it lacked the leap year, gradually moved the month of the new year further and further from Sirius’s heliacal rise.
This lead to a discovery of the Sothic year, 1461 years of ancient Egypt’s 365 day year or 1460 of the Julian sidereal year which adds leap years. A Sothic year follows the gradual movement of the New Year until it once again occurs when the Nile floods, synching up with Sirius’s heliacal moment.
In spite of my long established affection for Orion, or perhaps because of it, I’ve never focused on Sirius. That’s a bit surprising since Canis Major is Orion’s hunting dog and Sirius is the brightest star in the night sky. I’ll be looking for it as rises this year here on Shadow Mountain, probably August 10th.
When I see it, I’ll think of this from the Sky and Telescope article because it reflects my own wistfulness for a reenchanted world:
“While the first sighting of Sirius may not signify anything as momentous as the annual flooding of the Nile, seeing it tenderly twinkling at dawn can take us back in time to when it was commonplace for people to use stars to mark important events in their lives. How far we’ve strayed.”