Searching for Periodicity in Protoplanetary Nebula
Arts and Sciences
Physics and Astronomy
Protoplanetary Nebula (PPNe) are a stage of stellar evolution that falls between the Asymptotic Giant Branch Stars and Planetary Nebula (PNe) stages. Many PPNe tend to display a cyclical variation in their brightness. In a 2010 paper by Dr. Bruce Hrivnak, he reported initial periods of twelve PPNe. My goal for the summer is to confirm or refine the periods for six of those PPNe, along with finding possibly new secondary periods within the light variation of these six PPNe. These objects have been reanalyzed due to the availability of new, publicly available All-Sky Automated Survey for Supernova (ASAS-SN) data and new data from the Valparaiso University Observatory. In order to go about this analysis, I have begun with photometric data gathered from the ASAS-SN online database. This data is reduced, then analyzed through a period search program known as Period04. Period04 fits a Fourier Series to the data, allowing us to find the most likely frequency of variation, and thus the period at which the PPNe is varying at. This will then be followed by a similar analysis of the new VUO data. In this poster, I will be presenting the periods and amplitudes found by this study, and comparing them to the previously found results. Periods of ~81 days were found in two of the stars, with another found for a third star, with a period between 220-290 days.
This research is supported by a REU grant from the National Science Foundation.
Bakke, William, "Searching for Periodicity in Protoplanetary Nebula" (2021). Summer Interdisciplinary Research Symposium. 107.