Variability Studies in Proto-Planetary Nebula and Hypergiant Candidates
Dr. Bruce Hrivnak
Arts and Sciences
Physics & Astronomy
As stars age, they go through stages in their life cycles. After the red giant branch, medium mass stars enter the proto-planetary nebula stage on the way to becoming a planetary nebula before turning in to white dwarfs white dwarves, and high mass stars enter the hypergiant stage on the way to supernova. We observe about 25 of these stars on clear nights using the VU Observatory. We combine the nightly data for each star into light curves and analyze the curves for periods in brightness variation as well as other relations. These findings are useful for determining the physical properties of the stars as they evolve. My individual project involves studying 2 suspected hypergiants, IRAS 19114+0002, IRAS 19244+1115, and one proto-planetary nebula candidate IRAS 20004+2955. I will present the light curves of these three stars and describe the results of my period analysis of the data. I have found periods ranging from 100 to 300 days. My mentor for the project is Dr. Bruce Hrivnak and our funding comes from the National Science Foundation and the Indiana Space Grant Consortium.
Freund, Stephen, "Variability Studies in Proto-Planetary Nebula and Hypergiant Candidates" (2015). Symposium on Undergraduate Research and Creative Expression (SOURCE). 460.