Skip to main content

About this free course

Download this course

Share this free course

In the night sky: Orion
In the night sky: Orion

Start this free course now. Just create an account and sign in. Enrol and complete the course for a free statement of participation or digital badge if available.

1.3 Mapping the stars

A photograph of the night sky, showing Orion.
Figure 19 The constellation of Orion

Looking again at the constellation Orion, you can see that there are many stars in the constellation that are not labelled.

All the main stars in the constellation of Orion have names. They have ‘scientific’ names and ‘historical’ names. Here are two pictures of Orion; in one, the stars are labelled with their scientific name and in the other, they are labelled with their historical name.

An image of the night sky showing the different stars making up Orion.
Figure 20 The scientific names of the stars that make up the Orion constellation
An image of the night sky showing the different stars making up Orion.
Figure 21 The historical names of the stars that make up the Orion constellation

Usually, the brightest star is given the designation ‘Alpha’. So the brightest star in the Orion constellation is known as ‘Alpha Orionis’ or ‘Alpha Ori’ for short. It is also called ‘Betelgeuse’.

An image of the night sky.
Figure 22

How many stars are there? We don’t know! We can’t see them all. When we look at the night sky, all the stars we can see with the naked eye are in our own Galaxy, the Milky Way.

In the next section you’ll find out about the European Space Agency mission to study the stars.