During the 1860s,a hypothetical planet named Vulcan,in a solar orbit closer to the Sun than Mercury,was proposed as the cause of abnormalities in Mercury's orbit.Much of the 1860s and 1870s was spent studying the solar disk waiting for Vulcan to cross.Vulcan never appeared (but we learned a great deal about sunspots!).This technique is like which exoplanet-discovery technique?
A) distorted protoplanetary disks
B) the transit method
C) the radial-velocity method
D) the astrometric method

Question

Quizplus · Accepted Answer

The technique described involves observing the solar disk for a planet crossing in front of the Sun, similar to the transit method used in exoplanet discovery, where a planet passes in front of its star, causing a temporary dimming of the star's light.

During the 1860s,a Hypothetical Planet Named Vulcan,in a Solar Orbit