22nd Annual Student Research Conference
Phase Dependent Spectroscopic Monitoring of Cepheid Variable Stars
Bandon B. Decker
Dr. Matthew M. Beaky, Faculty Mentor
Cepheid variables are pulsating yellow giant stars, with a temperature slightly greater than that of the sun. There is very little data on how the spectra of Cepheid variables change over time. Especially interesting is the O I triplet at 7774 Angstroms, since how it changes over one pulsation cycle is related to the motion of un-ionized oxygen in the atmosphere of the star as it pulsates. Three classical Cepheid variables, FF Aquilae, T Vulpeculae and SU Cygni were observed spectroscopically at the Truman Observatory. For all three, it was possible to determine the change in surface temperature as a function of phase. Analysis of the strength of the O I triplet is ongoing, but there is clear variation over a single pulsation cycle. We expect to detail the changes in the equivalent width of the triplet as a function of phase for all three stars.
Keywords: Cepheid, Spectroscopy, Physics, Astronomy, Stars
Topic(s):Physics
Presentation Type: Oral Paper
Session: 38-4
Location: VH 1412
Time: 2:00