Let us take a more detailed look at the Andromeda galaxy. It is one of our
closest neighbours in the local group of galaxies and it is often called the
Milky Way's sister galaxy as it is very similar to our own Milky Way. Both
galaxies are spiral galaxies of a very similar age and size.
We are going to try and work out the number of stars found in Andromeda. Andromeda
is at a distance of around 2 million light years. It’s the furthest
object that can be seen with the naked eye. Andromeda is however so far away
that the light that we see today left Andromeda over 2 million years ago.
At these kinds of distances it is not possible to see individual stars –
only with special techniques and the largest telescopes is it possible to
make out a single star.
So how can we find the number of stars in Andromeda?