Booth Id:
PHYS039
Category:
Physics and Astronomy
Year:
2018
Finalist Names:
Clarke, Leonardo (School: Minnetonka High School)
Abstract:
Astronomers who measure light levels of stars have noticed that not all stars emit light at a
constant rate. By the 20th century, a star called “RR Lyrae” was discovered to be a variable star
whose light levels fluctuate. As a result, a group of variable stars was designated “RR Lyrae
variables” after the original star RR Lyrae. This study focused on RR Lyrae stars and a
phenomenon that is associated with them: The Blazhko effect. RR Lyrae variables have primary
pulsation periods which represent periods of short-term brightness fluctuation. The maximum
amplitudes of these fluctuations change over time in a (sometimes) periodic fashion known as
the Blazhko effect. The exact causes of the Blazhko effect are not completely understood. This
study sought to take a sample of RR Lyrae variable stars, plot their primary pulsation periods,
and see if they have a positive correlation with the amplitude or the period of the Blazhko effect.
RR Lyrae variables’ light levels are measured by astronomers to gauge distances to globular
clusters within and outside of the Milky Way galaxy. Pursuing studies into how these stars
behave will further astronomers’ understanding of these fundamental tools of measurement,
which could, in turn, contribute to advances in the study of the expansion of the universe as well
as large-scale stellar migration patterns.