Stellar spectra

Definition

Stellar spectra are the range of electromagnetic radiation emitted by stars, analyzed to determine various properties such as temperature, composition, and velocity. They appear as lines or bands of color when light from a star is dispersed through a prism or diffraction grating.

5 Must Know Facts For Your Next Test

1. Stellar spectra are classified into different types based on their spectral lines, including O, B, A, F, G, K, and M types.
2. The absorption lines in stellar spectra correspond to specific elements present in the star's atmosphere.
3. The Doppler effect can cause shifts in the spectral lines, indicating whether a star is moving towards or away from us.
4. By analyzing the width of spectral lines, astronomers can infer information about a star's rotation speed.
5. Temperature differences among stars result in variations in their spectra; hotter stars emit more blue light while cooler stars emit more red light.

Review Questions

• What information can be determined by analyzing a star's spectrum?
• How do spectral lines help identify the elements present in a star?
• What does a redshift or blueshift in stellar spectra indicate about the movement of a star?

Related terms

Spectral Classification: A system used to categorize stars based on their spectral characteristics.

Absorption Lines: Dark lines in a spectrum caused by absorption of specific wavelengths by elements in a star's atmosphere.

Doppler Effect: A change in frequency or wavelength of light from an object moving relative to the observer.