Of the first exoplanets found,most were detected by:
A) noting the drop in the star's light as the planet transits its disk.
B) imaging them with the HST in the infrared, where they are easier to stop.
C) noting the Doppler shifts of the star as the planet orbits it from side to side.
D) receiving radio transmissions from them, much like Jupiter emits.
E) detecting the oxygen in their atmospheres spectroscopically.

Question

Quizplus · Accepted Answer

The first exoplanets were mainly detected by observing the Doppler shifts of the star as the planet orbits it from side to side. This method is known as the radial velocity or Doppler spectroscopy method. As a planet orbits a star, it exerts a gravitational force on it, causing the star to wobble slightly. This wobble produces a Doppler shift in the star's light, which can be detected by analyzing its spectrum. By measuring this Doppler shift, astronomers can infer the planet's mass, orbital period, and distance from the star.

Of the First Exoplanets Found,most Were Detected By