SBO project

Measuring & interpreting the solar center to limb variation at different wavelengths

Note that this page carries a revision number (see the bottom of the page). Given that this project will evolve as we obtain more experience and insights, this page will be updated. Therefore, when referring to this page, always write down the revision number.

Todo list for the observations

  • Keep a log of your measurements. You will need this to write a meaningful account of our measurements. Record the date & time of day, the weather conditions in meaningful intervals, and any issues with the apparatus and the telescope, etc.
  • Take pictures and describe the apparatus briefly. Again this will be part of your project report.
  • Determine Iλ(μ) by scanning with the spectro-photometer across the solar disk. Make sure you cover reasonably well both limbs. Check this before taking data for `production runs'. Record spectra in fine enough intervals (either 13 or 26 points corresponding to 10 or 5 revolutions on this little `crank'. Make sure yoou can translate the revolutions into μ and estimate an error for this procedure.
  • Repeat measurements at least 3 to 5 times. Double-check that the weather is ok all the time. If small clouds appear, make a clear note of this. Such data are in principle useless, but maybe you can learn something from them anyway. Write down any irregularities in the measurements. This might help in tracing the course of systematic changes that might occur over the 1.5 months period that measurements are taken.
  • If there is time, perform additional experiments that you can think of. This will give you extra points and the five best innovative ideas will be rewarded at the end.
  • Determine the solar spectrum in integral light without telescope by going outside with the with the detector and computer.
  • Determine the angular characteristics (angular dependence) of the detector. Try to fit this dependence locally around the maximum to a cosnθ dependence, where θ is the angle from the normal.

    Regarding the theoretical interpretation

    For the case of a gray atmosphere (no λ dependence), see Homework key 2.

  • Back to main course page
  • notes on the analysis
  • See Lecture 37 for further details
  • Paper: PierceSlaughter77.pdf
  • Link to Axel's idl directory
  • Link to sample tex directory
  • Student scripts

  • Schedule


    Axel Brandenburg
    $Date: 2016/04/29 16:50:11 $, $Author: brandenb $, $Revision: 1.12 $