Crowded Field Photometry of star clusters

AIM AND OBJECTIVE

The aim of this experiment is to obtain your own observations of two star clusters with our 50cm telescope, to reduce the collected data and then interpret the obtained information. Besides the distance we will also derive physical parameters such as age and metallicity using different methods.

OBSERVATIONS AND METHODS

For this experiment you will observe 2 different clusters in 3 different photometric bands (BVR – blue, green and red). To allow later analysis of the obtained data we will also obtain photometry of several calibration stars. With this data we can use the DAOPHOT package to extract magnitudes and colors for all stars in the field and plot them as a color-magnitude diagram (see above). By overplotting and matching a range of theoretical isochrones that describe the shape and position of the diagram as function of time and metallicity we can derive the distance to the cluster, the foreground reddening, as well as its age and metallicity.

INSTRUCTIONS AND MATERIALS

  • Project instructions: German – English (Google translated)
  • How-to Guide to controling the telescope and CCD camera: German – English (Google translated)
  • Short reference manual for the Mr. Miller data reduction pipeline: German – English (Google translated)
  • Data Reduction with Mr. Miller – Step by Step: German – English (Google translated)
  • Stellar photometry using DAOPHOT: German – English (Google translated)