GEMINI

The Gemini constellation above the eastern horizon
The Gemini constellation above the eastern horizon.
Till Credner - Own work, AlltheSky.com
CC BY-SA 3.0, wikimedia
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Map of the Gemini constellation.
CC BY-SA 3.0, wikimedia

Gemini is one of the easiest constellations to see in winter, even in cities with light pollution, thanks to its brightly shining stars Castor and Pollux. The constellation is known for containing an important meteor shower called the Geminids, a rich shower of fireballs that peaks in mid December.

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Castor and Pollux as portrayed by Johannes Hevelius.
Johannes Hevelius (28 January 1611 – 28 January 1687)Scanned by Bronger - Atlas Coelestis.
Johannes Hevelius drew the constellation in Uranographia, his celestial catalogue in 1690.
CC BY-SA 3.0, wikimedia

In Greek mythology the Dioscuri (Gemini), the twins Castor and Pollux, were the children of Leda from Sparta who was impregnated by both her husband Tyndareus and by Zeus. She gave birth to four children, two immortals (Pollux and Helen) and two mortals (Castor and Clytemnestra). At the death of his brother Castor, Pollux asked Zeus to give him his brother’s immortality, which he did, and the brothers were placed near to one another in the skies.

Athough Pollux is the Beta star, it is the brightest. It is 34 light-years from us and is an orange giant star. It is the closest giant star to the Solar System. It has an extrasolar planet made up of gas called Thestias.

In addition to being the second brightest star in the constellation, Castor is also one of the most beautiful multiple stars in the sky. Although it looks like a triple star, each component is in fact double and so the system is made up of 6 stars. It is slightly less than 51 light-years from us.
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M35
Oliver Stein - web site of Oliver Stein,
CC BY-SA 3.0, wikimedia

The open cluster M35 is in theory visible to the naked eye as a nebula but with a pair of binoculars, stars can be made out. It is 2,800 light-years from the Earth and its mass is equal to about 3,000 solar masses.

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Eskimo Nebula NGC 2392.
NASA, ESA, Andrew Fruchter (STScI), and the ERO team (STScI + ST-ECF)
spacetelescope.com,
Public domain,wikimedia

Another interesting object is the NGC 2392, the Eskimo nebula also referred to as the Clown nebula. The name Eskimo comes from a circular crown of gas that when photographed looks like the hood of a parka worn by the Inuits of Greenland.

Northern Hemisphere: Gemini can be seen in the early evening from December to May. The best time to see the stars is right after sunset in February when the constellation is high on the southern horizon.

Southern Hemisphere: the constellation can be seen at the same time of the year as in the northern hemisphere. At the southern middle latitudes, around February right after sunset, we can find it just above the northern horizon.