The first technique that allowed astronomers to find exoplanets involved:
A) photographing the planets using infrared waves
B) looking for the decrease of light from the star during a transit of the planet across its disk
C) sending a very small spacecraft to the exoplanet to take close-up images
D) measuring changes in the radial velocity (Doppler shift) of the star caused by the pull of orbiting planets
E) simply taking a visible light photo of the planet around the nearest star; it wasn't that hard

Question

Quizplus · Accepted Answer

The first technique that allowed astronomers to find exoplanets was measuring changes in the radial velocity (Doppler shift) of the star caused by the pull of orbiting planets. This technique became known as the radial velocity method or the Doppler method. By observing how the spectrum of a star changes over time, researchers can detect the wobble of a star caused by the gravitational pull of an exoplanet.

The First Technique That Allowed Astronomers to Find Exoplanets Involved