Question

A typical stellar spectrum (a plot of intensity versus wavelength) includes a number of deep indentations in which the intensity abruptly falls and then rises. These deep indentations are called ____ lines.

Answer 1

Answer:

They are called absorption lines

Explanation:

Absorption lines are defined as dark lines or lines having reduced intensity, on an ongoing spectrum. A typical example is noticed in the spectra of stars, where gas existing in the outer layers of the star absorbs some of the light from the underlying thermal blackbody spectrum.