As winter arrives, so will a variety of new constellations in the night sky visible from Los Altos.
According to Professor Geoff Mathews, who teaches astronomy at Foothill College in Los Altos Hills, the Earth’s rotation around the sun causes the night side of the Earth to face different parts of the galaxy, creating a "shifting cast of characters."
Within the 88 official constellations that appear during the winter, Mathews said only some are easily visible. Pegasus and its companion constellations, Perseus and Andromeda that trail it to the east, are visible by sunset, but Mathews advised that the best time to view them is 9 p.m., when they will be "high overhead, just southwest of the zenith." By December, they will disappear before the sun rises.
Currently, Orion, Taurus and Ursa Major become visible a few hours after sunset, with Orion’s dog Canis Major joining them at midnight, according to Mathews. He said Orion is easily identified by its belt, featuring several bright stars in a clear pattern that can be used as benchmark stars for locating other constellations.
Mid-December is the prime time to view Orion and the other constellations in the grouping, Mathews said. At that time, Orion will rise as the sun sets, and all of the constellations will be visible throughout the night.
For the best view, Mathews recommended driving up into the hills to avoid light pollution in the city. The first step in becoming an experienced stargazer, he said, is to familiarize oneself with the subject with sky maps. (A review of various star atlases is available at tinyurl.com/staratlas.) The next steps are to spend some time outdoors learning the constellations by eye and then to purchase a pair of binoculars.
Mathews also suggested joining a community of sky-gazers. The Peninsula Astronomical Society, for example, opens the Foothill College Observatory to the public 9-11 p.m. every Friday. The sessions feature talks from professional astronomers who regularly provide feedback on stargazing skills. The college is located at 12345 S. El Monte Road, Los Altos Hills.
While there are no constellation-centric events in the area, Mathews said presentations on general astronomical knowledge are abundant.
To view a video tour of the highlights of each month’s sky, visit the Hubble Telescope website at hubblesite.org/videos/tonights_sky.❄