Many Light Years Away

In the article “Potentially Habitable Exoplanet Found Close Enough for Us to Study Its Atmosphere Soon” It talks about how a Super-Earth known as LHS 1140b lies 39 light years from the solar system.  This means that it is close enough for telescopes to detect something.  The planet was discovered by the M Earth South Survey in Chile, which is a range of small telescopes that looks for the dips in starlight when planets pass in front of nearby stars.  However, there another way to detect exoplanets.  This is done by using the Doppler Effect.  Which describes the changes in frequency of any kind of sound or light wave produced by a moving source.  When the star moves away from us its light is red shifted and when the star moves towards us the light is blue shifted.  When this happens repeatedly you can calculate a planets mass.  Ironically in class we learned about the Doppler effect as well.  On page 75 in the lecture tutorial book we did an exercise about the Doppler shift where four observers were pictured along with four different wave lengths.

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As a class we determined that observer C will receive light that is blue shifted as the star is moving toward them because the light was giving off shorter wavelengths and observer B will receive light that is red shifted as the star is moving away from them because the light was giving off longer wavelengths.

In conclusion to get information about objects in space far away from Earth, astronomers need something from those objects that carries information to Earth.  That something happens to be light.  Light carries a ton of information.  It tells us how various objects exist, how bright they are, their composition, how hot they are, how dense they are,  and how they are moving.  Light are waves that travel through space.  The light that your eyes can see is known as visible light.  Different wavelengths of visible light are seen as different colors by your eyes.

After reading this article and learning more about this conceptual objective, I have a better understanding about the significance of light.  Before reading the article I did not know how much information light alone tells astronomers. The more I learn about the universe the more intrigued I become, because there is so much information I would have never known before this class.

 

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