November Skies 2010

With the arrival of November there’s no denying the coming of winter. Chilly temperatures and brisk winds define the major weather changes along with the one hour time shift that now comes a week later than in previous years. While sunrise seems ‘better timed’ early in the month, it’s the very early sunsets that catch our attention.  The time change provides an advantage for skygazers – we can start earlier.  So what’s to be seen?

By 10 p.m. the big three constellation of the summer, Lyra, Cygnus, and Aquila, with their bright stars Vega, Deneb, and Altair (respectively) are now just above the western horizon and will soon retire until next summer. Of note is the Swan of Cygnus. With its new nose-down orientation, it’s much easier to see the bright stars as a cross standing upright on the horizon. Deneb becomes the top, the bird’s wings are the crossbar and the bill of the swan is the foot of the cross.

Taking center-stage this season is the mythical winged horse Pegasus, who was ridden by the mythical Greek hero Perseus.  Pegasus looks like a big square in the sky marked by four reasonably bright stars, one at each corner of the box. In the myths, Perseus rides Pegasus as he defeats the gorgon Medusa and rescues Andromeda, daughter of the Ethiopean queen Cassiopeia and King Cepheus. Each of the characters mentioned here, except Medusa and Zeus, are constellations prominently placed near Pegasus. Zeus has no representation in the sky while Medusa is represented by the variable star Algol in Perseus.

Also running across the sky, just below Pegasus, is the Zodiac band of constellations. From west to east they are Capricornus, Aquarius, Pisces, Aries, Taurus, and Gemini. Their singular astronomical significance, as a group, is that the sky paths of the sun, moon and planets flow through the constellations of the zodiac.

Around in the north, the big bear of the sky Ursa Major is now ‘nose up’ on the horizon. Its most famous sub-group of stars, the Big Dipper, stands on its last handle star, Alkaid.  To the east, the Winter Circle of Orion, Taurus, Auriga, Gemini and Canis Major fill the east after midnight.

Our largest planet, Jupiter, is bright and easy to spot in the south as the sky darkens. Just to the east of Jupiter Uranus sits quietly, difficult to see without a telescope. Thirty degrees to the west is our most distant planet, Neptune. Even a small telescope under dark, clear skies will reveal their dim disks. Very low in the west both Mercury and Mars fight to be seen above the deepening sunset glow. In the pre-dawn sky over in the east, Saturn is well up an hour before sunrise. The brightest planet of our skies, Venus, is also visible, following not far behind Saturn.