Lab 5:Spectroscopy

Objectives:Use spectrum emission lines to characterize the light observed coming from a distant star.Background:Spectroscopy is a powerful tool used in a multitude of disciplines. As light is emitted or absorbed by an object, the light coming in will changes in specific ways specific to the material. Each element and compound has specific and discrete wavelengths of lights that can be absorbed or emitted. When the light comes out of an object like the sun it may appear that the light is homogenous to some degree if not slightly yellow/orange. We know from Snell’s Law n1sin(ϴ1)=n2sin(ϴ2) Eq(1).that light passing from one substance to another turns depending on the index of refraction. This is called refraction, but it isn’t the complete story. Dispersion is the name given to the phenomenon of the refractive index not being a constant, but rather n(λ) depends upon the wavelength, λ. This means light of different wavelengths (colors) will be diffracted through different angles. Now with this we can observe that when the light from the sun passes through a prism it doesn’t just bend. The light splits up and becomes a rainbow as the different colors that made it up split apart. If we combine this with the fact that different elements only emit specific wavelengths of light, we can take incoming “white” light and split it into the wavelengths that make it up and determine what elements made the light.

Introduction:

Analysis:Part 1:You are observing the sun and have a spare prism laying around. This is a good time to confirm some information about the sun. As the light passes through your prism the light splits into its component wavelengths as seen bellow.

Now that the light has been separated you can see clear dispersion lines.

1.) From these emission lines, what is the sun made of?

2.) Suppose instead the above spectra contained the two elements carbon and oxygen. What can you say about the existence of C, O, CO, or CO2 in the system? Explain.

Part 2:Now intrigued by being able to see what the sun is made of you turn your sights to a distant star.While observing this star the incoming light dims slightly making you believe an object has transited the sun. When this happens the object absorbs some of the light from the star and reemits it giving you a new emission spectra. You get new emission lines:

How many elements are in this transiting object? What are they?

What is the object?

Is there any significance to the object observed with this spectra? Why?

Conclusions:Brief summary of the procedure and analysis:

If doing this in real life what types of things would you need to take into consideration as possible sources off error. (Not measurement or human error)

Hydrogen:

Helium:

Lithium:

Beryllium:

Boron:

Carbon:

Nitrogen:

Oxygen:

Fluorine:

Neon: