Science Lab-What are stars made of?

Lab Report for Lab #5: What Are Stars Made Of?

Questions:

1. Download and save or print out comparison spectra. The Astrophysics Data System (ADS) is a resource that houses electronically scanned refereed publications in astronomy. Find the article written by Jacoby, Hunter and Christian in 1984, published in the Astrophysical Journal Supplement (ApJS). The article is titled “A Library of Stellar Spectra.” The spectra that you are interested in begin on page 259 of this article. The ADS is found at http://adswww.harvard.edu/

2. Describe the differences of the main spectral types. Considering only the letters that denote the spectral class (O, B, A, F, G, K, M), determine the characteristics that separate one class from another based upon their spectra. Be sure to notice both peak wavelength and absorption lines.

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3. Go to the ELODIE website to view stellar spectra. ( http://atlas.obs-hp.fr/elodie/ ) Look up and view the spectra of the stars from the list below. Identify the spectral type of each star by comparing the spectrum on ELODIE with the library from the article found in step 1. Be sure to note both the peak wavelength of the curve and any absorption lines you notice.

HD 191984

HD 194244

HD 206778

HD 209747

HD 210418

HD 211976

HD 212754

HD 212943

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4. Use the WWT to find each star whose spectrum you identified. Use the research button to find out the correct spectral type for the star by checking the spectral type on SIMBAD.

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OPTIONAL Step 5. Write a paper about the determination of spectral classes of stars. Write about what you have learned about the spectra of stars and how the spectra are related to the chemical composition of stars. Include anything you learn about the history of stellar spectral classification.