Light Variation and Period Studies of Southern Proto-Planetary Nebulae

Faculty Sponsor

Bruce Hrivnak and Wenxian Lu


Arts and Sciences


Department of Physics and Astronomy

Presentation Type

Poster Presentation

Symposium Date

Summer 2014


Stars go through many stages in their evolution. Proto-Planetary nebulae (PPN) are the recently discovered phase between the Red Giant and Planetary Nebula stages. PPN have been known to change in brightness and size. Brightness measurements were made on 25 PPN at the Valparaiso University (VU) Observatory this summer. Our observations will be combined with previous observations to search for periodicity. Knowing the periods of pulsation will be useful in determining the internal structure of PPN. Several of the observed PPN have shown to fluctuate with a cyclical period. In addition to continuing observations for this long-term project at the VU Observatory, we have observations from the SARA-South telescope in Chile for 9 new proto-planetary nebula candidates. These objects have only been observed for 1 to 4 years each and the data sets are small. They were searched for periodicity and preliminary values were found. Three of the 9 objects appear to have periods that will be investigated with further observations. This research is supported by the National Science Foundation (NSF) MSEED grant No. 1068346 to VU and by an NSF grant (AST 1009974) to Prof. Bruce Hrivnak.

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