VU Physics and Astronomy Colloquium

Friday, January 16, at 3:20 PM in NSC 224. Join us for refreshments in NSC 231 at 3:05 PM.

"Summer Undergraduate Research"

Chris Wagner, Ryan McGuire, and Sam Schaub, Dept. of Physics & Astronomy, Valparaiso University 

"A Search for Light Variability in Proto-Planetary Nebulae"
Chris Wagner
This project deals with some stars that produce planetary nebulae.  We know
that these planetary nebulae have central stars.  To figure this out, we
are looking at the central stars of these nebulae, but not during this
phase.  We are looking at the stage right before planetary nebulae, known
as proto-planetary nebulae.  We are specifically looking to see if these
central stars are actually binary systems.  To do this, we are looking for
variability in the central star.

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"Light Variability in Seven Bright Proto-Planetary Nebulae"
Ryan McGuire

We are presenting new data of seven bright proto-planetary nebulae, which
were observed over the summer of 2008. Proto-planetary nebulae are objects
evolving between the Asymptotic Giant Branch and planetary nebula phases.
We know from previous monitoring that the brightness of the proto-planetary
nebulae varies over time. Over the course of this past summer, we have been
trying to find the main causes for the brightness fluctuations.

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"A Photometric Survey to Search for Close Binary Stars in Planetary Nebulae: First Results"
Sam Schaub
I present the first stage of results for an ongoing photometric
survey of the central stars of planetary nebulae. The survey is designed
to search for photometric variability associated with close binary
companions to the central star. Such variability may be observed via
eclipses, irradiation of the inner hemisphere of a cool companion, or
gravitational distortions of one or both stars. Results of the completed
survey will help us better understand the binary fraction of planetary
nebula central stars, which in turn will help us understand if binary
interactions are the major mechanism producing the variety of morphologies
observed in these nebulae