Ask A Scientist© Astronomy Archive

Question:  What is the distance from Earth of the stars that make up the Big
Dipper constellation?
Ssample

Answer:  This information comes from my World Almanac. The distance to the main
stars of the Big Dipper ranges from about 68 light-years (ly) to about 210
light-years, as shown here:


  210 ly --> *     * <-- 88 ly

                      * <-- 68 ly

                          *          * <-- 105 ly


                 90 ly --> *        * <-- 78 ly


Most of these stars do actually belong to a single open star cluster
(I don't think the 210 ly one belongs, though). The stars of a given
constellation need not have any physical relationship to each other.
They may be vast distances apart; we simply associate them because they happen
to be in the same general direction, from our viewpoint.
Rcwinther