Sohan Kshirsagar

Finding Blue Stragglers

Mentor: Charles Oravec, Physics Department

Major: Physics, Computer Science

Funding: Undergraduate Research Center Summer Research Fellowship


Using astronomical techniques, such as photometry and photo calibration, in conjunction with images taken from the Hubble Space Telescope archive of 4 renowned globular clusters, color-magnitude diagrams were generated in search of blue stragglers. The ages of the clusters were also discovered by fitting isochrones to the diagrams. 47 Tucanae, M3, M12, M14 were found to be 10.5, 11, 12.6, 13 billion years old, and contain 11, 11, 22, and 45 blue stragglers respectively. It was discovered that as the age of the globular clusters increased, there was also an increase in the number of blue stragglers as well as the number of bright blue stragglers. Furthermore, since there were a similar number of yellow stragglers as there were blue stragglers, new theories were proposed about the evolution of blue stragglers. The process of making color-magnitude diagrams was made modular during this research, making any future repetitions of this project seamless.


Watch my research presentation below.

Questions or comments? Contact me at: