Date of Award

Spring 2022

Document Type


Terms of Use

© 2022 Jiaming Wang. All rights reserved. This work is freely available courtesy of the author. It may only be used for non-commercial, educational, and research purposes. For all other uses, including reproduction and distribution, please contact the copyright holder.

Degree Name

Bachelor of Arts


Physics & Astronomy Department

First Advisor

David H. Cohen


We apply two mass-loss rate diagnostics described in the thesis on Chandra and XMM-Newton X-ray spectroscopic measurements of ζ Pup, one of the most luminous stars in the Milky Way and one of the closest O stars to Earth. Emission line profile analysis from new long Chandra grating observations taken during 2018 and 2019 indicates a significant 40% increase in ζ Pup’s wind mass-loss rate as compared to data taken in Chandra’s first observation cycle in 2000. Broadband spectral modeling of 20 years of XMM observations also reveal non-periodic wind mass-loss rate variation at a 40% level on timescales of months to years. These results are surprising as the mass-loss rates of massive stars are predicted to be constant.