Signs in the sky, some of them spooky

Wednesday, October 28, 2015

My original plan was to discuss the celestial ocean this week with all the "aquatic" constellations now floating in the southern sky after sunset, but I am going to put that on the back burner for a week since we are now close to Halloween.

Halloween has always had an astronomical connection and not all of them are necessarily "spooky."

First, let's look at the day itself. The date, October 31, is very near what is called a "cross-quarter" day, or a day that is halfway between an equinox and a solstice, in this case the autumnal equinox--the start of autumn -- and the winter solstice -- the beginning of winter.

Nothing particularly spooky about that, however, Oct. 31, is the day before Nov. 1, which was observed in many cultures as the "Day of the Dead" when all kinds of spooky things were supposed to happen.

In the old Celtic calendar it is called "Samhain" which in the Celtic dialect is pronounced "Sowin." Don't ask me, I am not an old Celt.

Along that line, there are some monsters and other "spooky" things located among the stars. First there is Draco, the Dragon, located between the Big and Little Dippers in the northern sky. The beast's tail is between the dippers with the writhing, twisting body winding up and to the left.

The critter's head is a triangle of stars located just below the outstretched wings of Cygnus, the Swan.

Another monster is the head of Medusa being held by Perseus, the hero of the Andromeda story. Look for a group of stars shaped like the capital letter "A" just above the northeastern horizon. Medusa's head is represented by the star Algol (also called The Demon's Eye) about about where the line crosses the middle of the "A" shape.

Algol is an eclipsing binary star that changes brightness every 2.8 days and has been likened to the blinking eye of the beast. Ancient mythology said that one glimpse of the snaky-haired head would turn anyone who saw it to stone.

Another of the starry beasts is Cetus, the Sea Monster, also associated with the Perseus/Andromeda/Cassiopeia/Pegasus story only it is located clear across the sky above the southern horizon. It is also part of the celestial ocean group, so I am going to save it until later.

Now, for the really spooky beastie of many ancient Halloween legends -- the tiny star cluster of the Pleiades. What!?! Tiny, harmless, little Pleiades? Yep, they are closely associated with the Day of the Dead.

In the ancient Aztec, Inca, Maya, Olmec, and Toltec empires in Central America and Mexico, Nov. 1, was celebrated as the Day of the Dead when the souls of those who had died came back.

It was also observed that at midnight on that date the Pleiades stood directly overhead at midnight.

Now, since these cultures knew nothing of the Greek and Roman mythologies, they had their own which put the seven stars in that group up to a sinister purpose.

Today the Pleiades are no longer directly overhead at midnight. Precession -- the wobble of Earth's axis -- has moved that event one full month later to Dec. 1. We won't need to worry about Daylight Saving Time, because that ends on Nov. 1.

SKY WATCH: Third-quarter moon, Nov. 3. Daylight Saving Time ends at 0200 hours on Sunday, Nov. 1.

Turn your clocks back one hour. In our early morning planet dance, Mars and Venus have their close meeting before dawn on Monday, Nov. 2. They will be about a half-degree apart.

That is about the width of the full moon.

NEXT WEEK: The Celestial Ocean, and more astronomical blathering.

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