Learning More About Stars

When you think about stars and how they form, can you answer the following questions (you may like to look at the images in Figure 1 below to help):

  • do stars tend to 'group' together?
  • are all the stars in a group similar in appearance?
  • are all these groups the same physical size?
  • do all the groups have a similar number of stars?
  • are all these groups equally dense/sparse?

Figure 1: A globular (left) and open (right) cluster.


One particular type of grouping of stars (such as that on the left in Figure 1) is a globular clusterAnother one you may be familiar with is an open cluster (above right). Astronomers are keen to classify stars by their appearance and often do this by means of a colour magnitude diagram (or CMD).

Scientists break these colour images down into those of individual parts of the optical spectrum, typically blue, green and red (although astronomers confusing abbreviate these to B, V and R; where V stands for visual). The data that we get from telescopes come in a format known as FITS files. This stands for Flexible Image Transport System. Typically, colour images will require 3 FITS files. Many of these images come from the Liverpool Telescope (LT) or the Faulkes Telescopes (FTs). You can find out more about how telescopes work. CCDs (Charged-Couple Devices) are the detectors used in the cameras on telescopes to allow us to produce such detailed images.

Find out more about open clusters.

Find out more about globular clusters.

Read more about the most common type of stars.

See an example of a colour magnitude diagram.