solar spectra power point lesson part 3 what is our sun made of[1] (1)

7/28/2019 Solar Spectra Power Point Lesson Part 3 WHAT is OUR SUN MADE of[1] (1)

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WHAT IS OUR SUN MADE

OF? 94 % Hydrogenthe most abundant gas in the

universe and 6 % Helium

All the other elements make up just 0.13% (withoxygen, carbon, and nitrogen the three mostabundant metals---they make up 0.11%). Inastronomy any atom heavier than Helium is calleda metal.

If you use the percentage by mass, you find thathydrogen makes up 78.5% of the Sun's mass,helium 19.7%, oxygen 0.86%, carbon 0.4%, iron0.14%, and the other elements are 0.54%.


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How do we know what our sun is made of?

SPECTROSCOPY:

Spectroscopy uses white lightand scatters it using a prismor diffraction grating. When

white light passes throughheated gases, as in the Sun,it is scattered at differentwavelengths. Atoms andmolecules can be identified

by their signaturewavelength numbers orcolor.


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History and study of

Spectroscopy"Spectroscopy is the science of using spectral lines

to figure out what something is made of. That is

how we know the composition of distant stars!"

In the 1660's Isaac Newton had shown that

sunlight can be separated into separate chromatic

(color) components via refraction through a glass

prism. (splitting apart white light)


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History and study of

Spectroscopy In 1817, Joseph von Fraunhofer, independently

rediscovered the 'dark lines' in the solar spectrum noticed15 years earlier by William Hyde Wollaston.

Fraunhofer pursued the matter mainly because he saw thepossibility of using the lines as wavelength standards to beused to determine the index of refraction of optical glasses.

Other physicists, however, were quick to realize that theFraunhofer lines could be used to infer properties of thesolar atmosphere, as similar lines were being observed inthe laboratory in the spectrum of white light passingthrough heated gases. This discovery is what later lead tosome of the more important advances in solar physics.


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How we use Spectroscopy today: Astronomers commonly refer to stars by their

spectral type or color determined bytemperature and chemical gas composition of thestar.

The OBAFGKM classification

O = 28,000K to 50,000KBlue stars - Hottest

B = 10,000K to 28,000K

A = 7,500K to 10,000K

F = 6,000K to 7,500KYellow stars

G = 5,000K to 6,000K (Our Sun)White star

K = 3,500K to 5,000K

M = 2,500K to 3,500KRed stars - Coolest


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Spectroscopy in Astronomy:

today, most

information

gathered on the

Sun and stars

is obtained

through

spectroscopicmeans.


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Layers of the Solar Atmosphere at different wavelengths:


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~The Lesson Activity:~Solar Spectra: A look into temperatures and

elements present on the Sun

Students will learn to interpret graphs showing

emission and absorption lines of atoms in the solaratmosphere.

***Teachers please see entire lesson for: student

prerequisites, opening activities, day by day tasks,

purpose, objective, assessment, vocabulary list, websitelinks and related lessons. As well as an explanation of

an emission and absorption graphs.


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Understanding the Graph:


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Lab Group Duties:

Work Together!

Choose one person to be

each of the following

(1) Leader

(2) Timekeeper

(3) Note taker

(4) Recorder-description of each in full lesson plan

under assessment.


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What is expected of you? 1. For you to work

together with your group. One person should NOT be

doing all the work!

2. To complete the labchartand worksheetEachgroup member must dotheir own! (Although only one lab chart

needs to be turned in foryour groups grade eachstudent must fill out thechart to keep in their notes!)

3. Ask questions if youneed help!

solar spectra power point lesson part 3 what is our sun made of[1] (1)

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