When nearby stars are observed over a period of a year, their positions are seen to move in tiny ellipses relative to the background of more distant stars.
Explain why relative movement of these nearby stars is observed.
By means of a labelled diagram, outline the steps necessary for this effect to be used
to find the distance to nearby stars.
The effect is too small for the distances to more distant stars to be determined.
Outline a method which can be used for more distant stars.