North is to the
NGC 6946 is located
just 10 million light-years away, in the constellation of Cepheus.
During the 20th century, at least six supernovae, the death
explosions of massive stars, were discovered in NGC 6946. The most
recent nova was 2004et.
This high frequency of supernovae is the reason for the Fireworks
NGC 6939 is at a
distance of about 4000 light years in the Orion Arm of the galaxy.
This is a region of very rich molecular clouds.
Because NGC 6946 and
NGC 6939 are at a low galactic latitude, we view them through dust
and various nebulae. This causes the light to become reddish, just
as the Sun is red at sunset. This effect is called Galactic