Orion is one of the most striking constellations in the night sky, and in the northern hemisphere is clearly seen in winter from November to February. Fortunately, it is also one of the easiest ones to spot and by using Orion as a reference point we are able to locate some of its surrounding constellations fairly quickly.
Orion represents a legendary hunter from Greek mythology, with the constellation’s second and third brightest stars, Betelgeuse (red supergiant) and Bellatrix, forming the giant’s huge shoulders. Orion’s belt lies on the celestial equator and so Orion is equally visible from both hemispheres. The imaginary sword hanging from his belt contains the Orion Nebula (M42) while further below, the blue super giant stars Rigel and Salph form the giant’s legs
Taurus: A line through Orion’s belt leads up to the constellation of Taurus, where a distinctive triangular shape of 6 stars (the Hyades) form the bull’s head, with the large red star called Alderbaran depicting the bull’s fiery red eye. Following the same line a little further, you will come to the Pleiades, also known as the seven sisters. This open star cluster is dominated by hundreds of hot blue stars, only a handful of which can be seen with the naked eye.
Canis Major lies south east of Orion and represents the giant”s chief hunting dog. In Latin Canis Major means ‘big dog’ and included in this constellation is Sirius, meaning ‘dog star’, which is the brightest star in the night sky. Any object brighter than the -1.46 magnitude Sirius is likely to be a planet and not a star.
Canis Minor (“the lesser dog”) consists mostly of a single white star called Procyon, the 8th brightest star in the night sky, and a faint blue star called Gomeisa . Procyon is Greek for ‘before the dog’ and is seen rising in the sky roughly an hour before the dog star Sirius. However, Procyon is actually a binary system containing one of Earth’s nearest neighbouring stars at just 10 light years distant.
Auriga: A line from Orion’s first leg and the first star in his belt leads onto the distinctive pentagon shaped constellation called Auriga (“the charioteer”). It contains an impressive bright, yellow star called Capella, which is the sixth brightest star in the night sky.
Gemini is a zodiac constellation found by imagining a line running through Rigel and Betelgeuse onto the stars of Pollox and Castor, legendary twins from Greek mythology who went on many great adventures together. The two bright stars you see depict the twin’s heads side by side, while the fainter stars outline their two bodies.
Leo is a zodiac constellation laying a little further on from Gemini and forming a distinct sickle shape of stars starting with the brightest called Regulus. The three zodiacal constellations already mentioned lie on an eliptic line 18 degrees wide known as the Zodiac and following this line will lead you onto the other zodiac constellations.