M38 is the third of the three Auriga
clusters. It is about 4,200 light-years away and has a linear
diameter of around 21 light-years. The cluster has a total
visual magnitude of 6.4 and contains more than 100 stars. The
brightest stars of the cluster have been said to form a Greek
letter Pi, or according to some, an oblique cross. M38 is of
intermediate age at about 220 million years. It is a large
cluster and is easily viewed with binoculars. In telescopes, it
is best viewed at low power.
