How do you astronomers use spectra to determine the composition of a star?

Answer 1

They pass the light from a star into a diffraction grating, I believe, to give a widely spread out spectrum of the star's light. The elements and compounds present will of course emit (or absorb, I don't remember) light at specific wavelengths, thus identifying the elements present.

Answer 2

Scientists apply the emission spectra to investigate the chemical composition by using a prism to split the star's light and observe wavelengths that show higher intensity than others. These wavelengths are compared to the emission spectra of known gases to determine the chemical composition of stars.

Answer 3

The answer is long and complicated, and it is too long to place here.

You need to read an entire encyclopedia articles on spectroscopy and the chemical composition of intersteller objects.

D.A.W.

Answer 4

Got this from wikipedia;

Newton used a prism to split white light into a spectrum of colour, and Fraunhofer's high-quality prisms allowed scientists to see dark lines of an unknown origin. It was not until the 1850s that Gustav Kirchoff and Robert Bunsen would describe the phenomena behind these dark lines; hot solid objects produce light with a continuous spectrum, hot gasses emit light at specific wavelengths, and hot solid objects surrounded by cooler gasses will show a near-continuous spectrum with dark lines corresponding to the emission lines of the gasses.[5]:42-44[10]By comparing the absorption lines of the sun with emission spectra of known gasses, the chemical composition of stars can be determined.

Answer 5

The emission spectrum tells us how hot the star is.

Answer 6

They study patterns in light bands that are separated from starlight by the spectroscope

Answer 7

The composition is determined by spectral analysis.