The sky at night

Gemini, the Twins, belongs to the magnificent assemblage of brilliant constellations that spangle our winter sky. It lies just to the north- east of Orion and can easily be located by following the Hunter's raised arm. Its two principal stars, Castor and Pollux, are both first magnitude. Pollux, marginally the brighter, is an orange giant, contrasting with the bluish white appearance of Pollux. Scientific scrutiny of Pollux reveals that it is in reality a system of six stars. Small telescopes can distinguish three, all of which turn out to be close doubles. Where Orion's uplifted arm almost touches the more northerly twin's foot lies a glorious star cluster. At fifth magnitude, it is in principle visible to the naked eye, though a very dark sky would be necessary. This is an object best viewed with binoculars. Surprisingly, it has acquired no name, either classical or fancifully descriptive. It is simply M35.

Jacqueline Mitton