Periodic Light Variability in Proto-Planetary Nebulae

Faculty Sponsor

Bruce Hrivnak


Arts and Sciences


Physics and Astronomy

Document Type

Poster Presentation

Symposium Date

Summer 7-29-2019


We are studying pulsational variability in proto-planetary nebulae (PPNe), an evolutionary stage of stars between the red giant and planetary nebula stages. Photometric observations of PPNe have been carried out over 10 years (2008-2018), primarily at the Valparaiso University Observatory, and supplemented by observations from the SARA consortium telescopes. Additionally, we have acquired data from the All-Sky Automated Survey (ASAS-SN), which has observations going back 4 years (2015-2018). This second dataset has lower precision, so those with the largest uncertainties have been removed. We are studying a sample of 18 stars. Using a Fourier analysis package called Period04, dominant periods have been searched for in both the VUO dataset and the ASAS-SN dataset. These periods will be compared with one another and ultimately for those with dominant periods with the general trends and ranges characteristic to these objects as seen in the literature.

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