Category

Photometry

Differential Photometry

Differential Photometry is comparing the difference between a target star and a comparison star. This is most usefulin Time Series observations.

The direct comparison of a target and comparison star in the same field of view eliminates all other observationalvariables leaving a direct, differential comparison. Example: light pollution.

IMPORTANT: This process does NOT derive an absolute magnitude measure, but instead provides differential/relativemagnitude changes.

To accomplish this, we use Aperture Photometry.

NOTE: If you have not viewed this lesson, pause and review itbefore proceeding here.

Key Elements:

  • Understanding Aperture Photometry
  • Understanding what a Comparison Star is
  • Stellar Magnitudes
  • Image Calibration
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