Astronomers can determine the maximum size of a distant, luminous object by
A) directly resolving it in a telescope only.
B) using trigonometric parallax.
C) timing the fluctuations in its luminosity.
D) looking for the amplitude of an oscillating Doppler shift.
E) using the phenomenon of radio wave diffraction.

Question

Quizplus · Accepted Answer

Astronomers can determine the maximum size of a distant, luminous object by timing the fluctuations in its luminosity, as the time it takes for light to vary can provide an upper limit on the size of the object.

Astronomers Can Determine the Maximum Size of a Distant, Luminous