Andromeda is a constellation in the northern sky. It is named after Andromeda, the princess in the Greek legend of Perseus who was chained to a rock to be eaten by the sea monster Cetus. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and remains one of the 88 modern constellations.
The most famous deep sky object in Andromeda is the spiral galaxy Messier 31 or the Andromeda Galaxy, one of the most distant objects visible to the naked eye (Messier 33, the Triangulum Galaxy, is slightly farther). It is an enormous spiral galaxy much like the Milky Way. To find the galaxy, draw a line between ß and µ And, and extend the line approximately the same distance again from µ
Some examples are Messier 31 (spiral)