Gemini
The twin stars of winter
Best on December–February evenings · northern sky.
Gemini is one of the winter sky's most satisfying constellations — two bright stars side by side mark the heads of the twins, with neat parallel chains of stars trailing down to form their bodies. It sits comfortably north of the celestial equator and is a showpiece for northern hemisphere observers on winter evenings.
How to find it
On winter evenings, look northeast of Orion's Belt and Betelgeuse — scan up and left from Betelgeuse and you'll run straight into two closely matched bright stars sitting side by side. Those are Pollux and Castor, the heads of the twins. From there, two gentle strings of stars stretch downward in parallel, outlining the twins' bodies all the way to their feet near the Milky Way.
Brightest stars
Pollux leads the constellation at magnitude 1.14, shining with a warm yellowish glow. Castor, just a couple of degrees away, follows close behind at magnitude 1.98, with bright white Alhena (magnitude 1.93) marking one twin's foot.
Worth seeing
The pairing of Pollux and Castor is the real reward — two bright stars close enough to compare side by side, a rare chance to notice color difference between stars with the naked eye.
Frequently asked
When is Gemini visible?
Winter evenings, roughly December through February, when the twins climb high in the northern sky for northern hemisphere observers. It's well placed from southern latitudes too, though it sits lower on the horizon there.
What are the brightest stars in Gemini?
Pollux is the brightest at magnitude 1.14, followed by Alhena at 1.93 and Castor at 1.98. The two heads of the twins — Pollux and Castor — are the most famous pair, sitting just a few degrees apart in the sky.
Which hemisphere is Gemini best seen from?
Gemini is best seen from the northern hemisphere, where it climbs high on winter evenings. It's still visible from the southern hemisphere but stays lower in the sky.
Nearby constellations
Cancer · Auriga · Orion · Taurus · Canis Major · Leo · Ursa Major · Perseus