The spectrum of an ordinary main-sequence star is a
A) continuum of colors, crossed by brighter lines caused by emission from the hot atoms and molecules on the star's surface.
B) smooth continuum of color, peaking at a specific wavelength whose position depends on the star's surface temperature.
C) series of emission lines, mostly from hydrogen, the major constituent of stellar surfaces, that occasionally overlap to produce sections of continuous color.
D) continuum of colors crossed by dark absorption lines caused by absorption by cooler atoms and molecules at the star's surface.

Question

Quizplus · Accepted Answer

The spectrum of an ordinary main-sequence star is characterized by a continuum of colors crossed by dark absorption lines. These absorption lines are created when light from the hotter, denser interior of the star passes through the cooler outer layers. Atoms and molecules in these cooler layers absorb specific wavelengths of light, leading to the appearance of dark lines in the spectrum. This phenomenon is known as absorption spectroscopy and is a key tool in astrophysics for determining the composition, temperature, density, and velocity of stars.

The Spectrum of an Ordinary Main-Sequence Star Is a