Finding Variability in Proto-Planetary Nebulae
Bruce J Hrivnak
Arts and Sciences
Department of Physics and Astronomy
We are observing 44 evolved stars that are in the phase between red giants and white dwarfs. This stage is called proto-planetary nebulae (PPNe). We have observed these objects on 21 clear nights so far this summer. Nearby comparison stars are also observed along with the PPNe each night. We then reduce these images to get quantitative measurements of the brightness. The measurements are then plotted as light curves to show the variation of brightness over time. This variation in light is due to pulsation of the PPNe. For our project this summer we are combining our data with observations made since 2008. We are analyzing the variation of light in a subset of 12 PPNe. We are finding periods of variation that range from 40 to 160 days.
Jackson, Avery M.; Bremer, Matthew T.; and Vogl, David M., "Finding Variability in Proto-Planetary Nebulae" (2017). Summer Interdisciplinary Research Symposium. 4.