The star Castor represents one of the twins of Gemini. Although we see it as a single point of light, Castor actually consists of three sets of stellar twins, for a total of six stars.
Unless otherwise specified, viewing times are local time regardless of time zone, and are good for the entire Lower 48 states (and, generally, for Alaska and Hawaii). Check out last week's tips if you missed a night.
Pollux, the brightest star of Gemini, is in the east at nightfall, below its slightly fainter “twin,” Castor. Pollux shines with a distinctly orange hue, indicating that its surface is relatively cool.
Epsilon Geminorum, one of the brighter stars of the constellation Gemini, is in the east in early evening. The star is about 150 times the Sun’s diameter, so it’s visible to the unaided eye even though it is about 900 light-years from Earth.
The star cluster M35 is in the east at nightfall, at the feet of Gemini. Although the cluster is more than 2,500 light-years away, under dark skies it’s visible to the unaided eye as a fuzzy blob of light. Binoculars enhance the view.
The Great Square of Pegasus stands high in the west at nightfall. The star Alpheratz stands at the highest point of the square, and it’s the brightest of the square’s four stars.
Sirius, the brightest star in the night sky, rotates across the south on winter evenings. It’s low in the southeast at nightfall, and it’s hard to miss. Not only is it especially bright, it’s also especially twinkly.
The Moon will swing quite close to Jupiter tonight. The planet looks like a brilliant cream-colored star, and stands just to the left of the Moon as night falls.