Sky at night

It's winter now and the famous constellations of the winter sky are coming out in full glory. The picture above shows the outline of the constellation of Orion, my favourite in the night sky. As you may be aware, many of the constellations are related to Greek mythology, and Orion is no exception. There are various legends and myths around this figure, this link gives but one of them. Basically, you see Orion the Hunter, with a sword (containing the famous Orion nebula, M42 (Messier object 42)), a club raised above his head and a shield raised to his right. If you extend Orion's belt down to the left, you'll come across the Dog Star, Sirius, the brightest fixed star in the sky. Its magnitude is -1.4. Magnitude is an inverse logarithmic scale, i.e. the brighter the star, the lower the value. The planet Venus, currently visible in the early evening sky, has a magnitude of -4, the full moon is -14 and the sun is -28. The weakest stars visible to the naked eye have magnitude +5; the planet Pluto is +14 and can only be seen with a strong telescope.

Extending up to the left from Sirius you come across Procyon, the Little Dog Star and Castor and Pollux, the Gemini or Twin Stars.

To the right of Orion rears Taurus, the Bull, with Aldebaran as its bloodshot eye. This image is currently augmented by the presence of another bright red object, the planet Mars. A fuzzy cluster of stars between Orion and Taurus resolves with a pair of binoculars into a group of 7, which is known as the Pleiades.

The legend around Orion dictates that he will never be in the sky at the same time as his slayer, Scorpio. When he rises, Scorpio sets; and vice-versa.

Take a coat, but above all: enjoy.

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