Projects in Astronomical Techniques

A project in the astrophysics of stars course, where the goals were to first investigate the spectra of two main-sequence stars and to calculate the equivalent widths of the Hβ and Ca II K absorption lines. Then, calculate the fraction of neutral H atoms that are in the first excited state (for Balmer lines like Hβ) and the fraction of Ca II ions that are in its ground state (for the K line).

In our investigation, we wrote about the differences in ratios and wrote about how the equivalent widths alone do not necessarily tell us about the relative abundances of H and Ca. The equivalent widths are primarily sensitive to the varying rates of ionization and excitation in different stars, resulting from temperature differences. Therefore, equivalent widths for elements vary with the effective temperature of a star.

Professor: Dr. Sumangala Rao Sudhakar (Dr. Rao)