RESEARCH INTERESTS
Multiperiodic Pulsating Stars
I am working on pulsating variable stars known as RR Lyrae stars along with collaborator Dr. Edward Schmidt of UNL.
These are low-mass older stars whose brightness varies over time because they are actually pulsating. Most
of these stars pulsate with only one period on the order of 0.3 to 0.8 days. These stars repeat their light curves
with remarkable regularity (BK AND, for example). However, some RR Lyraes show a much
longer secondary periodicty. These are known as Blazhko Effect stars and they have considerable scatter to their
light curves (FM PER, for example). The cause of the Blazhko Effect is still unknown. We are
working on developing a database of the characteristics of Blazhko Effect stars and regular monoperiodic RR Lyrae stars.
It is hoped that a correlation between the presence of the Blazhko Effect and another parameter can be found that might
shed light on its cause.
Eclipsing Binary Stars
These stars come in pairs and they vary in brightness because one star actually eclipses (cuts in front of ) the
other star. The major focus of this work so far by myself and collaborator Dr. Kam-Ching Leung of UNL has been the star KV GEM.
This star was originally classified in the General Catalogue of Variable Stars as an RR Lyrae (RRc) star. However, our V
and R photometric data clearly show KV GEM to be an eclipsing binary. The Delta V light curve of
KV GEM is displayed here along with the V-R color data. The very low correlation coefficient (0.41)
between V and V-R is indicative of an eclipsing binary. One would expect a much stronger correlation for an RRc star.
Skeletonization of Large Protein Molecules
This project is under the leadership of Dr. Prabir Bhattacharya of UNL's Computer Science Department. We are
applying image processing techniques to electron density maps taken by X-Ray Diffraction Crystallography.
We hope to develop a 3-D greyscale skeletonization
algorithm useful for finding the skeletal structure of large protein molecules.
