List of questions for F30: CCD photometry in modern astronomy

Part I: Characterizing a CCD

• How does a CCD chip work in principle?
• What are the advantages of a CCD chip compared to the eye or a photographic plate?
• What is the dark current, how is it measured during the experiment and how can it be reduced?
• What relevance has the silicon bandgap in the experiment? How can it be determined?
• What are the meanings of the terms linearity, conversion factor and read-out noise for a CCD, and how to measure them?
• What are the data reduction steps necessary to get from raw images to the photometrical analysis?

Part II: Photometry of a star cluster

• What are star clusters, and where are they found?
• Hertzsprung-Russel diagram (HRD) and color-magnitude diagram (CMD):
  • What is a HRD?
  • What are the differences between a HRD and a CMD?
  • How many frames are needed to create a CMD?
  • How and why can the CMD be used to determine the age and the distance of a star cluster?
• How are instrumental, apparent and absolute magnitude defined?
• Photometry:
  • What is aperture photometry?
  • What is a point spread function (PSF) and what determines its shape?
  • How to determine the PSF in the experiment?
  • What are the differences between aperture and PSF photometry?
  • How are aperture and PSF photometry combined in the experiment and why?
• What is the photometric calibration and how is it performed?