Our Sun was the first star whose absorption spectrum was analyzed. In 1814, Bavarian physicist Joseph von Fraunhofer (1787-1826) recorded the strongest dark lines, now called Fraunhofer lines.
Sun's ¡absorption spectrum
Figure 3.7. Astronomers identify iron in the Sun by matching dark lines in the Sun's absorption spectrum to a reference iron emission spectrum.
Since then astronomers have catalogued thousands of dark lines in the Sun's spectrum. By comparing these lines with the spectral lines produced by different chemical elements on Earth, they have found over 70 different chemical elements in the Sun (Figure 3.7).
How can the chemical composition of stars be determined? Assume that stars and their atmospheres are made of the same ingredients._
Answer: By analyzing the dark lines in the star's spectrum and comparing them with those of each of the chemical elements on Earth.
Was this article helpful?