Primary Submission Contact

Matthew Bremer

Faculty Sponsor

Bruce J. Hrivnak

Faculty Sponsor Email Address


Arts and Sciences


Physics and Astronomy

Document Type

Poster Presentation


Fall 10-26-2018


We are carrying out research to determine the pulsation period of a specific stage in evolved, low-mass stars’ life cycles called Proto-Planetary Nebulae. Our datasets come from The Valparaiso University Observatory (VUO), as well as The All Sky Automated Survey – All Sky Catalogue (ASAS-ASC), and The All Sky Automated Survey for Supernova (ASAS-SN). These datasets complement each other to ensure that we get high-quality data for our very faint objects over long intervals of time in both hemispheres. The VUO has been observing on this project for over 20 years. The ASAS-ASC and ASAS-SN data recently became open to the public and we are using them in our analysis. We are using these three datasets to search for periodic photometric variability in 48 evolved stars. We do this by using a sophisticated period search program called Period04. Our research has found 18 objects that have one or more significant periods ranging from 37 to 208 days.

Biographical Information about Author(s)

Matthew Bremer is a Junior Astronomy and Secondary Education Major, completing his second consecutive year working on this project. In previous summers, Matthew has been a part of the observing crew for this project and is now on the data analysis side. He is excited to apply the real-life skills he learned during the research process to his vocation as a teacher.