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Project B: Stellar Properties

In this project you will analyze data to determine fundamental properties of stars as a professional astronomer would.  You will need to use your understanding of astronomical theory to extract as much information as possible from the data provided. You may consult your notes, use your textbooks, the internet, and work with a partner to analyze the data.

The Data

You will be analyzing actual spectra from main sequence stars taken from the Sloan Digital Sky Survey (SDSS). SDSS is a major galaxy hunting experiment using two telescopes to gather spectra from galaxies. It also gathers spectra from some stars, which is the data we will use.

Your team will analyze the following stars. 

  1. RA = 196.31, Dec = 3.039
  2. RA = 206.848, Dec =1.595
The teams should analyze Star #1 first. After that analysis is complete and correct, it should be a simple matter to analyze star #2 if time permits.

To download the spectra for these stars 

  1. go to the SDSS Quick Look page and 
  2. Click on "Search" in the navigation bar on the left.
  3. The top of the page should show the search controls. 
  4. Enter the RA and Dec values for your star on the second line of the search controls and press "GO". 
  5. Click on "Get Spectrum as CSV" underneath the image of your star's spectrum.
  6. Right-click on the downloaded file and select "Show in Folder"
  7. Rename you spectrum  to "StarData.csv" and move it to someplace safe.
  8. Double-click "StarData.csv". It should open in Excel.

The file contains data representing the spectrum of a star. The first line describes the data that is included in the file. The subsequent lines contain the file data. Each line contains four values, separated by commas. The values you want are "Wavelength" and "Best Fit". You may delete the other two columns ("flux" and "skyflux"). 

Pay special attention to the units. Wavelength is measured in Angstroms, and flux is measured in 1E-17 ergs/sec/cm^2/Angstrom . You must convert to MKS units before you do any detailed data analysis. In MKS, wavelength would be in meters, and flux would be W/m^2.

Analyze this data and tell me as much as you can about your star.

It’s highly recommended that you take detailed notes on your work, detailing the steps you performed on the data, and justifying it using the theory we’ve studied in class. You will need to detail your analysis in your paper, poster, and presentation. Your notes will be crucial to your success.

Nikhil Joshi,
Mar 20, 2017, 2:41 PM