M31

The Andromeda Galaxy is one of the most magnificent objects in the night sky and undoubtedly the most famous galaxy outside our own Milky Way. Easily visible as a hazy patch to the naked eye, the galaxy covers as much of the sky as 5 full moons put together. Binoculars will show Andromeda in its entirety with a clear brightening towards the centre. Binoculars will also show two of Andromeda's companion galaxies, M32 and M110. Careful observation of the nuclear region with a telescope will reveal faint dust lanes and other structures. The Hubble Space Telescope has shown that the Andromeda Galaxy has a double nucleus, indicating that it may have cannibalized another galaxy. M31 was once thought to be a nebula inside our galaxy, but in 1923, astronomer Edwin Hubble showed that it lies outside the Milky Way. M31 is now thought to be about 2.9 million light years away. It is over 150 000 light years across, and has a mass 1.2 trillion times that of our sun.