Transcript Astronomy Day 2006: A short presentation on eclipsing binary stars

Astronomy Day 2006
A short presentation on eclipsing
binary stars presented by the
Dark Ridge Observatory
Thomas C. Smith, Director
http://www.darkridgeobservatory.org
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Dark Ridge Observatory (DRO) - West
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Stars
Just what are they? Why do we care?
 It is recognized as fact by astronomers
that well over half of the stars in the
universe belong to multiple systems.
 You might think of our Sun as being an
exceptional system that involves only one
star and you would be right.

ESA/NASA’s SOHO Images
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Multiple Star Systems

Just what makes a multiple system of
stars?
M-73
Credit to SEDS
A multiple star system is any star
system in which more than one
star is engaged in stable
gravitational interaction. Typical
multiple systems are binary stars,
two stars orbiting each other;
binaries can be orbited by a third
star, forming a ternary or triple
star, and there are more complex
cases like binaries orbiting other
binaries or ternaries, etc. Some
multiple star systems contain as
many as eight stars.
(source Answer.com)
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Binary Stars
Orbits for binary star systems
The Castor binary system
Sirius and Companion
Excerpts from the University of Tennessee
Astronomy 162 course
http://csep10.phys.utk.edu/astr162/lect/index.html
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Eclipsing Binary Stars
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Observing Eclipses
This is the way we view eclipses using a process called photometry
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Why Are They Studied?
The type of eclipsing binary stars that I am
studying are called contact or over-contact
binaries and these are in the last
evolutionary stage of this two-star system.
 From these stars we can learn about the
dynamic properties that exists in stars like
the mass transfer process and star spot
characteristics.

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What Might We Find?


Another reason that I am interested in these star
systems is the potential for the discovery of
extra-solar planets that theoretically can exist in
stable orbit around the binary star pair.
These might be seen through transit
observations of very high inclination angle binary
stars. After all, they are in near-perfect
configuration to observe a planet passing.
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Questions
?
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Thank You
And good evening!