Exercise: Hydrogen Emission Lines

  1. Open up the Spectra Suite software and observe the emission lines for Hydrogen in the sample from the carousel. 
     
  2. Fill in the table with the peak wavelenght of all observed hydrogen lines in the spectral tube.
     
  3. Examine the spectrum of your star.  How many emission lines do you observe?  How many absorption lines?
     
  4. Can you identify any of the spectral lines in your star as hydrogen using the spectra observed in Part 1?

Note: when you use this table and plot for Part 3, it is important to realize that the ordering of the lines does not change. This section of the lab will allow you to see a relationship between wavelength and colors of visible light, and will help you become familiar with the Ocean Optics Spectrometer.

Hints

  • You can freeze the spectrum graph in SpectraSuite in order to take detailed readings by clicking on the spectrum chart and pressing the pause button.

Background

As you learned in the Introduction to Spectroscopy lab, different elements absorb different wavelengths of light. One of the most commonly used spectral features in astronomy are the spectral lines of Hydrogen, called the Balmer lines. 

The lines are named, from longest to shortest wavelength: The Hydrogen Alpha, Beta, Gamma, Delta, and Epsilon lines (or in simplified notation – Hα, Hβ, Hγ, Hδ, Hε).  Your group will identify these spectral lines in a stellar spectrum.