They Might Be Giants/Ciardi and Howell

They Might Be Giants are using data from the Kepler mission to classify the brightness changes of giant stars in an effort to understand how the observed brightness variations of giant stars may relate to the different stages of giant star evolution.

We propose to perform a blind study of 200 giant stars identified as Red Giant Branch (RGB-hydrogen shell burning) or Red Clump (RC-helium core burning) from the asteroseismology study performed by Bedding et al. (2011). In order to complete a blind study, the students and teachers participating in the study will not know the classification of the stars until after the initial study and grouping has been performed We will use the NASA Exoplanet Archive to retrieve the Kepler data and perform period searches using the periodogram tool for each of the stars. As a prelude to ground-based studies, we plan to study patterns in the periodograms for the longer periods (> 10 days), rather than the shorter periods used by Bedding et al.. We will phase and phase-bin the strongest periods, examine their general shape and period distribution, and then perform a comparison of the top three periods by amplitude, phase, and power. In addition, we will build spectral energy distributions (SED) of each star to look for other characteristics that may help astronomers distinguish these two types of red giants. Characterizing giants using longer periods and SEDs will help astronomers identify them from ground-based observations. Our proposed study will help us characterize and classify the giants and then allow an “after-the-fact” comparison to the Bedding et al. results where >200 giants evolutionary state is known.