weak CN star analysis

In high school, I worked on a research project with my mentor Professor Puragra GuhaThakurta at the UCSC Astrophysics department. Our research project was primarily focused in the Andromeda Galaxy on a rare population of massive stars, which we named ‘weak CN stars’ because of the visible yet less magnified presence of cyanogen (CN) detected in these stars. Based on analysis of their stellar spectra, we determined that these 'weak CN stars' contain both molecules of carbon and oxygen in their atmospheres, which challenged a basic theory of stellar composition because typically evolved stars do not contain both. As part of my internship, I conducted analysis of stellar spectra and photometric data to learn more about these relatively unknown population of stars.

Our stellar data was collected by the Hubble Space Telescope, Keck telescope, and DEIMOS spectrograph. We examined stellar spectra to learn about the presence of carbon or oxygen based molecules within each star, and Color Magnitude Diagrams, which plotted stars' colors and luminosities.  The results of our research lead us to conclude that weak CN stars are part of a population of young massive stars called red core Helium burning stars (RCHeBs). Because RCHeBs are a relatively unknown population of stars, our research contributed to current understanding of the stellar compositions of massive stars like RCheBs.

After the internship, our team wrote about our findings in a paper that was selected a Semifinalist in the Siemens competition in 2016. We also submitted an abstract to the American Astronomical Society and presented a poster there in January 2017, which is shown below.