Cygnus (the Swan)
Constellation Patterns
The stars of a constellation are often far
apart from one another, but they appear
grouped together when viewed from Earth.
Albireo
Gienah
Cygni
Deneb
Sadr
1500 light-years
Delta
Cygni
1000 light-years
500 light-years
1 light-year = 9.5 trillion kilometers
Which two stars in Cygnus are farthest apart from each other
in space?
Constellations
If you want to find a particular place in the United States, it helps to
know the name of the state it is in. Astronomers use a similar system
to describe the locations of objects in the sky. They have divided the
sky into 88 areas named for the constellations.
VISUALIZATION
CLASSZONE.COM
View images of the
night sky taken
throughout the year.
A constellation is a group of stars that form a pattern in the sky.
In the constellation Cygnus, for example, a group of bright stars form
the shape of a flying swan. Any other objects in that area of the sky,
such as galaxies, are said to be located in Cygnus, even if they are not
parts of the swan pattern. The ancient Greeks named many of the
constellations for animals and imaginary beings.
Unlike the planets in the solar system, the stars in a constellation
are usually not really close to each other. They seem to be grouped
together when viewed from Earth. But as the illustration above shows,
you would not see the same pattern in the stars if you viewed them
from another angle.
What relationship exists among the stars in a constellation?
588 Unit 5: Space Science