Eclipsing Binaries in Globular Clusters

My dissertation research with Prof. Mario Mateo involves a monitoring survey of 10 Galactic globular star clusters with the aim of finding eclipsing binary stars around the main-sequence turnoff. The simultaneous photometric and spectroscopic analysis of these systems can be used to to directly determine the distances to these systems and to calculate turnoff masses for cluster stars, thus providing a fundamental check of stellar models at low metallicity.

An interesting side project in the search for binary stars has been the creation of differential extinction maps for the target globular clusters. That is, we determined how much extinction light from different parts of the cluster suffers due to dust along the line of sight to the respective cluster.

You may see the following:

• a copy of my dissertation ("A Search for Eclipsing Binaries in Galactic Globular Clusters", 140 pages): postscript (92 MB, color) or pdf (25 MB, b/w).
• any of the related publications below:
  • A Search for Eclipsing Binaries in Galactic Globular Clusters -- von Braun, K. 2003, PASP, 115, 272 [pdf version]
  • Photometry Results for the Globular Clusters M10 and M12: Extinction Maps, Color-Magnitude Diagrams, and Variable Star Candidates - von Braun, K., Mateo, M., Chiboucas, K., Athey, A., and Hurley-Keller, D. 2002, AJ, 124, 2067 [pdf version]
  • Variable Stars in the Fields of the Globular Clusters M10 and M12 - von Braun, K., Mateo, M., Chiboucas, K., Athey, A., and Hurley-Keller, D. 2002, BAAS, 199, 56.14 (click here for poster - 4.5MB pdf)
  • Variable Stars in the Field of the Globular Cluster NGC 3201 - von Braun, K., & Mateo, M. 2002, AJ, 123, 279 [pdf version] [online data]
  • An Extinction Map and Color-Magnitude Diagram for the Globular Cluster NGC 3201 - von Braun, K., & Mateo, M. 2001, AJ, 121, 1522 [pdf version] [online data]
  • NGC 3201 Photometry Results: Differential Extinction Map, Color-Magnitude Diagram, and Variable Star Candidates – von Braun, K., & Mateo, M. 2001, BAAS, 198, 42.07 (click here for poster - 13MB pdf)
  • Eclipsing Binary Stars in Globular Clusters; von Braun K. , Mateo M., & Yan, L. 1996, BAAS 189, 71.12 (click here to view the poster presented at the American Astronomical Society at their January 1997 meeting). This presentation includes our preliminary photometry results on NGC 6752, M15, and the radial velocity curves for the binaries in M71 discovered by Yan & Mateo (1994, AJ, 108, 1810).

 

Complete List of Publications

Click to see a color image of the globular clusters M10, M12, M92, NGC 5053, or NGC 3201. All are color composite images taken with either the MDM 1.3m telescope or the Las Campanas 1m telescope.