San Saba News & Star
Weather Partly Cloudy 76.0°F (70%)
Stargazer
The Great Winter Arc
Thursday, January 13, 2011 • Posted January 13, 2011

It’s the time of year when the Great Winter Arc region is prominent in the evening sky. One of my favorite regions, it is especially dazzling because it contains the greatest concentration of bright stars found anywhere in the night sky.

Of the 21 brightest stars in all the night sky, called 1st magnitude stars, seven are in the Great Winter Arc region.

The region contains six constellations — Orion, Taurus, Canis Major, Canis Minor, Gemini, and Auriga — and is home to the night sky’s brightest star and most famous star cluster.

Other than the Big Dipper, Orion the Hunter is probably the most recognizable constellation thanks in part to its three equally-bright and equally-spaced belt stars which are hard to miss.

Sitting in the middle of the Great Winter Arc region, it contains reddish Betelgeuse and white Rigel, two of the seven 1st magnitude stars. Three hours after sunset, look for Orion well up in the southeast.

While Orion is within the arc, it is not part of it. The arc starts with the night sky’s brightest star, Sirius, in Canis Major the Big Dog. Look for Sirius blazing below Orion.

The next star in the arc is Procyon two and a half fist-widths (held at arm’s length) to Sirius’ left. It is the only bright star in Canis Minor the Small Dog.

Two fist-widths to Procyon's upper left are reddish Pollux and white Castor, the heads of the Gemini twins with the rest of the constellation to the right toward Orion. (Castor barely misses being 1st magnitude.)

The arc ends at creamy-colored Capella, the brightest star in Auriga the Charioteer, the rest of which stretches downward toward Orion. Capella is three fist-widths above Castor.

The region’s final constellation is Taurus the Bull with the red star Aldebaran, the angry bull’s fiery eye. Aldebaran is two fist-widths above Betelgeuse.

And the Great Winter Arc region’s final treat is the lovely and famous Pleiades star cluster (also called the Seven Sisters) located just over a fist-width above Aldebaran.

* Sky Calendar.

* Jan. 9 Sun. & 10 Mon. evenings: The Moon is within a fist-width of Jupiter.

* Jan. 11-22 mornings: Venus passes within a fist-width to the left of Scorpius’ bright reddish star Antares.

* Jan. 12 Wed. evening: The Moon is at 1st quarter.

* Jan. 19 Wed.: The Full Moon is called Old Moon and Moon After Yule.

* Jan. 25 Tue. morning: The Moon, Saturn, and Spica form a triangle in the south, Spica being nearest the Moon.

* Jan. 26 Wed.: The Moon is at 3rd quarter.

* Naked-eye Planets. (The Sun, Moon, and planets rise in the east and set in the west due to Earth’s west-to-east rotation on its axis.) Evening: Brilliant Jupiter is low in the west and down by 11 p.m. Morning: "Morning star" Venus dominates the southeast with Saturn higher above. Mercury is visible as dawn breaks near the southeastern horizon much of the month.

Stargazer appears every other week. Paul Derrick is an amateur astronomer who lives in Waco. Contact him at 918 N. 30th, Waco, 76707, (254) 753-6920 or paulderrickwaco@aol.com. See the Stargazer Web site at stargazerpaul.com.

This article has been read 79 times.
Comments
Readers are solely responsible for the content of the comments they post here. Comments do not necessarily reflect the opinion or approval of San Saba News & Star. Comments are moderated and will not appear immediately.
Comments powered by Disqus