An astronomy graduate student takes a long-exposure picture with a CCD camera but forgets to turn on sidereal tracking. What will the picture look like?
A) The picture will be blank.
B) The picture will be blurry.
C) The picture will have long, thin star trails.
D) The picture will have many false colours.

Question

Quizplus · Accepted Answer

Without sidereal tracking, the Earth's rotation causes stars to appear to move across the sky. This movement, over a long exposure, results in long, thin trails of light from each star rather than distinct points.

An Astronomy Graduate Student Takes a Long-Exposure Picture with a CCD