barospection

Mystery Star Video Script

  1. Goal is to learn about the process of determining a Star Type (Color, Temperature, Luminosity) etc. and to get input data to construct a Hertzsprung Russell diagram (HRD).
  2. In this assignment you will be using the Google HRD Sheet for input/output throughout. So, access it and have it open in a browser at the ready.
  3. Each student will calibrate a single Aalibration A-star assigned to them using a 2-point calibration on RSpec.
  4. Each student will analyze and determine star type for 5 Mystery stars assigned to them. Most of the details will be in the video. Rough steps are:
    1. From Mystery Star assignment in website, Download the Instrument Response file. Put into a specific folder on your Windows desktop. You will need this later.
    2. From the Mystery Star assignment in website access the Google HRD Sheet. Open in a separate tab on browser and have it ready. You will need this.
    3. Access dropbox on browser in a separate tab, go to Images folder, & click search
    4. From google sheet copy-paste Calibration star BID into dropbox search
    5. Download the FITS file (not folder) matching this description. Put into a specific folder on your Windows desktop. You will need this later.
    6. Repeat above step for each of the FIVE of your assigned stars and download FITS file for them all (total of SIX stars)
    7. Open a clean RSpec from start
    8. Set the 2-digit precision
    9. Drag and drop the previously downloaded calibration star FITS file into RSpec
    10. Rotate horizontal if needed
    11. Move boxing lines to the top and bottom of star. Cinch it close without interfering with the star or spectrum
    12. Subtract the background.
    13. Click on Calibrate. Select 2-point Calibration
    14. Identify the zero-order by a click on the peak or donut hole with your mouse if star is defocused
    15. Then identify and click on the Hydrogen-Beta feature
    16. Then Apply. Note the 2-digit precision of the Pixel Resolution.
    17. Take a Screen Shot with visible file names of your profile curves to post in Slack and the Jupyter Notebook for later.
    18. Enter the Pixel Resolution in the Google HRD Sheet. Also fill out the Distance and Magnitude of the Star from the BID name into the Google HRD sheet.
    19. Validate The type of your 1st mystery star doing the following steps.
      1. Close all RSpec windows except main to start clean.
      2. Drag and drop the previously downloaded one of 5 mystery star FITS file into RSpec
      3. Rotate horizontal if needed
      4. Move boxing lines to the top and bottom of star. Cinch it close without interfering with the star or spectrum
      5. Subtract the background.
      6. Click Calibrate. Select 1-point Calibration.
      7. Put cursor on field marke “pixel #1”
      8. Enter the dispersion (Pixel Resolution) you previiosly noted if necessary in the dispersion field
      9. Identify the zero-order by a click on the peak or donut hole with your mouse if star is defocused Then Apply the calibration and close button on the calibration window
      10. Click on Color Wheel
      11. Click the 3dots (ellipsis) button to navigate to the instrument response file you downloaded previously and click on it and click Open button
      12. Click Apply to apply your instrument response.
      13. Click the synthesise button for color in bottom bar.
      14. Click Reference button and select the Reference Library.
      15. Click selection in Reference Library window to restrict only to visible wavelengths
      16. Start at the beginning (o5) reference by continuously clicking down or up arrow keys on the keyboard and see the magic of visual comparison between your corrected mystery star profile and standard reference profile!
      17. You will see the standard reference peak travel from the invisible ultraviolet wavelengths into the visible region and far infra-red regions as you click the mouse.
      18. Somewhere during your clicking the 2 curves will look very similar between the vertical Red lines bounding the visible region. Note the Star Type with best match (say a5v) going from hot O-types to cool M-types.
      19. “Best Match” means no crossovers and “being parallel”. You should also be looking at features matching.
      20. Now repeat the process again going backward from cool M-types to hot O-types. Again note the Star Type with best match (say g2iii).
      21. The correct answer is most probably between a5v and g2iii.
      22. Take a Screen Shot of your final star type determination with visible file names of your profile curves to post in Slack and the Jupyter Notebook for later.
      23. Do the process again by looking at the feature matches.
      24. There is so much to learn here during this process. Be observant all around!
      25. Note your final determination of star type into the Google HRD sheet. Also fill out the Distance and Magnitude of the Star from the BID name into the Google HRD sheet.
    20. REPEAT this last major step with all 25 or so sub-tasks for each of your 5 stars!
    21. YOU ARE DONE. CONGRATULATIONS!! YOU ARE AN AMATEUR SPECTROSCOPIST!!!