Solar Spectra: A look into temperatures and elements present on the sun

by: Vera Pape

Grade levels: 6th - 12th

Time Requirements: Approximately 2 to 4 hours preparation time and 5 to 10 class periods (50 minutes each)

Student prerequisites: Students should have learned about the periodic table of elements and element symbols, the four states of matter and composition of matter, the parts of an atom, chemical and physical properties and changes, convection currents, the electromagnetic spectrum, our solar system, light, vision and color. Students should also possess skills in graphing as well as reading and interpreting various graphs. Students should understand the English and Metric measuring systems and their conversions.

Topics covered by this lesson:

1. Our sun - its parts, composition and activity - includes sunspots, CME's etc.

2. How temperature affects the color of a star - as it appears to us in visible light

3. Types and classes of stars

4. Energy produced by electron loss and ionization

5. Solar spectrum and element absorption/emission lines

6. Solar and space weather and its effects on Earth

Optional ~ higher grade levels

1. Radiation, blackbody radiation

2. Wien's Law calculations

3. Hydrostatic equilibrium

4. Sunspots and the Zeeman effect

5. Doppler effect and stellar motions

Brief Overview: Students will look at various graphs and data from solar observatories and distinguish what elements are being releasted (emitted) and which elements are being absorbed in the sun's photosphere.

Unit Features:

Video - www.nso.edu

http://www.trincoll.edu/~bwalden/ast103/sun2.html

Images - www.nso.edu

http://cse.ssl.berkeley.edu

Simulations - www.nso.edu

Interactive Features - http://teachspacescience.stsci.edu/cgi-bin/ssrtop.plex

Electronic Bulletin Board – , www.hao.ucar.edu

Other Interesting Features –

Materials Required for this Lesson:

1. Background information for the teacher - available in this packet

2. Images - some available in this packet (others available online, see links in 'Lesson Plan References' and 'Related Lesson Plans')

3. Wireless network in classroom - for teacher demonstrations and simulations

4. Computer lab or computer carosel in classroom - for student groups or partners research on various websites provided

5. LCD projector and white screen to show DVD/CD Rom videos, power point presentation, and pictures to class

6. Student worksheets/labsheets and handouts - available on this site

7. Stop watches for lab activity

8. Sun Print Paper – if necessary – see DAY 1 activities

9. Blank transparency paper, wet erase markers, and overhead projector

10. STUDENTS: Will need a notebook and pencil

Teacher's Component - Solar Spectra Lesson

*Background Information,Explanations and Ideas (available in Power point)

*Web links to Images, Simulations,Tools,and Data used in Lesson

*Worksheets

*Handouts

*Vocabulary

*Homework Assignments

Student Activities - Solar Spectra Lesson

*Lecture Notes, Power point Presentation of Background Information

*Simulations,Images,Tools,Data that will be used by the student

*Explanations, Questions,and Activities

*Worksheets

*Handouts

*Vocabulary

*Homework Assignments

LESSON PLAN CONTENT: Solar Spectra

by: Vera C. Pape©

TABLE OF CONTENTS: *NOTE: Please read entire lesson before starting in classroom.

A. Purpose

B. Objective

C. Simulations, Tools, Data, Illustrations, and Images

D. Procedure (breakdown of lesson with day-by-day procedures)

E. Assessment

F. Extensions, Related Resources and Homework Assignments (Vocabulary List)

G. National Science Standards

H. References

I. Related Lessons

J. Handouts, worksheets, and graphs

A. Purpose:

The purpose of this lesson is to familiarize students with solar astronomy and with the processse of scientific research carried out by professional astronomers using up-to-date data resources. Students will be able to participate in an astrophysics lab accessing data from the National Solar Observatory. They should come away from this lab with an understanding of some of the processess astronomers, physists and solar physists go through while doing their research.

B. Objective:

Using this lesson will help your students become familiar with various types of spectra, particularly spectra from our closest star, the sun. Students will become familiar with how astronomers and physists use spectroscopy to distinguish what elements are being absorbed and what elements are being emitted based on temperature. Once your students become familiar with all background information, your students will look at various wavelength and intensity graphs and determine what element(s) are being absorbed or emitted. Students will calculate the wavelength on the graphs in nanometers to Angstoms. Students will then match up the converted calculations to the list of elements in The Catalogue to determine which element(s) is represented on the graph. Students will also use two general graphs showing emission and absorption to determine if the element is being emitted or absorbed by the sun's atmosphere. Students will also learn the purpose and importance to this work and research as it is pertanent to life on Earth.

C. Simulations, Tools, Data, Illustration, and Images: One for each student unless otherwise noted -

- References for Day 1 and 2 - background information in power point

presentation

- Light and Spectrum Illustrations – “A Diagram showing Continuum, Emission, and Absorption” go to http://cse.ssl.berkeley.edu/lessons/indiv/timothyk/em_gas.html and http://cse.ssl.berkeley.edu/lessons/indiv/timothyk/light_spec.html part of Timothy Key’s lesson plan ‘Sky Map’ and ‘Guest Investigator Puzzle’ see - http://cse.ssl.berkeley.edu/lessons/indiv/timothyk/skymap.html

- Catalogue List of Element Wavelengths – handout – attached file (see section ‘J.’ of lesson plan)

- Copy of all element absorption/emission graphs – attached files (see section ‘J.’ of lesson plan) One set for each group of students. Each set can be different.

- Chart for student data – attached file (see section ‘J.’ of lesson plan)

- Worksheet for lab activity – attached file (see section ‘J.’ of lesson plan)

List of Illustrations and Images used in this lesson:

Background information illustrations and images – *Also see Power Point presentation Notes.

http://eo.nso.edu/tlrbse/sites.htm = links to images, movies, background information and lesson plans

1. Our sun - its parts, composition and activity = www.nso.edu , (also has movies of granulation), ,

- France observatory images

http://zebu.uoregon.edu/~imamura/122/feb14/feb14.html "The Quiet vs. Active Sun" -images, jpegs, animations of the sun, sunspots, granulation, CME's, prominences etc.

http://zebu.uoregon.edu/~imamura/122/lecture-1/sun.html

2. How temperature affects the color of a star = , http://zebu.uoregon.edu/~imamura/122/lecture-4/mk.html "Spectral Classification" Chart, also see some links below for number 3 Types and classes of stars

3. Types and classes of stars = (periodic table of the elements), , www.astro.washington.edu/labs/clearinghouse/labs/spectclass/spectralclassweb.htm l ,

(chart: classification of stars),

4. Energy produced by electron loss and ionization =

http://zebu.uoregon.edu/~imamura/122/lecture-4/atomic.html

- diagram of atom with explanation

5. Solar spectrum and element absorption/emission lines = http://jilawww.colorado.edu/~pja/stars02/ , www.astro.uiuc.edu/~kaler/sow/spectra.html , www.astro.washington.edu/labs/clearinghouse/labs/labs.html

, www.noao.edu/image_gallery/html/im0600.html , http://zebu.uoregon.edu/~imamura/122/lecture-4/Kirchhoff.html

6. Solar and space weather and its effects on Earth = www.nso.edu , , www.noaa.gov

Optional - additional lessons and/or higher grade level -

1. Radiation, blackbody radiation = http://hea-www.harvard.edu/~efortin/thesis/html/Black_body.shtml

2. Wien's Law = www.astro.umd.edu/education/astro/sprop/wien.html , - gives a diagram of Wien's Displacement Law, http://astrosun.tn.cornell.edu/academics/courses/astro201/wiens_law.htm

3. Hydrostatic equilibrium =

4. Zeeman effect (sunspots) = ,

http://230nsc1.phy-astr.gsu.edu/hbase/quantum/zeeman.html ,

,

5. Doppler effect and stellar motions = http://hea-www.harvard.edu/~efortin/thesis/html/Doppler.shtml

D. Procedure:

From this lesson your students should be able to interpret and apply data and information learned as a result from analyzing graphs taken from the sun's atmosphere. Analyzation includes; what elements are present in the sun's atmosphere and are the elements being absorbed or emitted. Further investigation can be taking from these graphs such as Wein's Law calculations and Hydrostatic equilibrium, an optional lesson for higher grade levels.

The first two to three days of this lesson are mainly to prepare the students for the last day or two of the lesson. These first few days can be taught with or without computers. I have only provided rough guidelines because you will probably have to adapt these days to your needs and the class's abilities. If you are going to use a class period or half a class period to let students research these topics on line or do some of the complementing lessons, you will need one computer for each group of four students. Following are the details for teaching each day's lesson:

DAY 1 AND 2:

On the first and second day you should introduce your students to the subject of astronomy (stars and our sun in particular) if they are not already familiar with the topic. The first day or two of the lesson structure has been left flexible so that you can adjust the material to your class's needs, with a different level of introduction depending upon the previous experience of your class. I encourage you to allow your students to browse the world wide web of the various links provided in this lesson. These links contain various background information, images and animations of the sun, stars, and solar and stellar spectra. "Images and animations are one of the best ways to catch the students attention in the context of astronomy." Timothy J. Keys and Isabel Hawkins – ‘The Great Investigator Puzzle Lesson’

Students should have an understanding of the sun, its layers, composition and activity. Students should know the color of our star, the sun, as well as what determines a star's color. Students should be familiar with the different classes of stars and star colors. Students should comprehend how the sun produces energy by electron loss and ionization. Students should review light and spectrum information, wavelengths, the more familiar optical region and its relation to the emission spectrum and absorption spectrum. Finally students should example why it is important to study the sun and its activies. This final portion can be done before and after the lesson. To show students what they know, what they want to know, and what they learned - see ‘KWL chart’ below for more details.

This can be accomplished a variety of ways; lecture notes, handouts and class discussion, and web browsing (either teacher based browsing with LCD projector and white screen - students follow along, or student partner or group browsing, depending on your sources and student needs.)

Materials:

- References for day 1 and 2 - background information - see Power point presentation or you may use your own materials for teaching students the background information.

Light and Spectrum Illustrations –

- “A Diagram showing Continuum, Emission and Absorption” http://cse.ssl.berkeley.edu/lessons/indiv/timothyk/light_spec.html

- Computer(s) to show power point presentation and/or have students research and browse the web.

Teachers - if you prefer to do an opening lesson activity before starting the lecture/powerpoint, here are two ideas:

(1) KWL CHART: K = What you know (about the sun), W = What you want to know (about the sun), and L = What you learned (about the sun). This activity can be done before the start of this mini-unit lesson (K and W) and at the end of the mini-unit lesson (L).

Usually I use a blank transparency sheet with wet erase markers on the overhead projector and white screen. Each heading (K), (W) and (L) each have their own column. Students also draw the chart into their notebooks. Students come up with what to put in the chart. You can either do this as an entire class - prompting students with clues, cues and questions. Or you can have students complete the task in small groups.

(2) Sun Print Paper activity: This activity involves art, nature, investigation, and experimentation as well as fun for students! Pick up a package of Solar Print Paper at your local science museum or learning tools shop or you can order it on the web at Read the package for directions and ideas. Then let the students be creative!

DAY 3:

On the third day you should continue to review and familiarize your students to the background information.

For higher grade levels the second day should be taken to review the processes that professional astronomers go through to be chosen as an observer or guest observer or "GO" (pronounced gee-ohh), and thus be able to have access to satellites, information, and telescope data at various observatories and satellite based ground sites all over the world. Go through the Guest Observer Handout (adapted from Timothy J. Keys and Isabel Hawkins The Guest Investigator (GI) Puzzle) with the class and discuss ways in which your students can present themselves as professional astronomers. "Every student can include their educational background and every student has used at least one piece of observational equipment: their eyes! Using the ['GO'] Proposal Template, your students can write a proposal to observe. . ." the Sun with the Dunn Solar telescope or the Hilltop telescope at the National Solar Observatory in Sunspot, New Mexico. "This exercise can be done individually or in groups." {You may also choose, for high grade levels, to have the students or groups present their proposal to the class. Students can peer evaluate each other's proposals as part of the assessment. *see DAY 4

Materials:

- GO Handout (adapted from Timothy J. Keys and Isabel Hawkins, The Guest

Investigator Puzzle) - ‘GI’ Guest Investigator handout (visit: http://cse.ssl.berkeley.edu/lessons/indiv/timothyk/details1.html)

- GO Proposal Template (adapted from Timothy J. Keys and Isabel Hawkins,

The Guest Investigator Puzzle) – ‘GI’ Guest Investigator Proposal Template

(visit: http://cse.ssl.berkeley.edu/lessons/indiv/timothyk/details1.html)

DAY 4:

On the fourth day, your students should either be starting the 'GO' Guest Observer (or ‘GI’ Guest Investigator) process or completing it (for higher grade levels) by presenting their proposals to the class. (NOTE: The 'GO' or ‘GI’ assignment can also be given as homework!)

DAY 5:

On the fifth day, your students should be ready to do the Solar Spectra Wavelength and Intensity Graph Lab. You, the teacher should familiarize yourself with the answer key and graphs at the end of this lesson.

***(NOTE: Teachers, make sure you specify to your students what is expected of them while doing the lab activity and their lab group duties!)

Materials: One per student, unless otherwise noted

- Wavelength and Intensity Graphs - one set per group

- Chart for recording lab data and worksheet

- Stop watches – for students to keep track of time left in class period, one per group

- Catalogue List of Element Wavelength handout

Understanding the graph:

The y-axis shows the Intensity. Where the intensity is the highest, more photons are escaping the solar atmosphere. The x-axis shows the Wavelength of the atom represented on this graph. In order to figure out what atom is being represented, students must match up the average wavelength in nanometer to the wavelength in Angstroms on the Catalogue List of Elements (provided in this lesson for handout). Students should use the black lines on each of the graphs provided to figure out highest intensity and lowest intensity. Students will fill in the lab chart appropriately (provided in this lesson for handout).

{Converting nanometers (nm) to Angstroms (A): Multiply nm wavelength by 10 to get from nm to A. Divide A wavelength by 10 to get from A to nm.}

Example: 121 x 10 = 1210 or 1210 ÷ 10 = 121

The wavelength for Hydrogen in Angstroms is 1210. This is a Hydrogen atom line graph. The intensity at which most photons are being emitted is approximately 1.05 x 10‾¹º. The intensity at which most photons are being absorbed is approximately 2.5 x 10‾¹¹. (Emission lines are peaks outward or higher. Absorption lines are peaks or dips lower/downward.)

DAY 6:

On the sixth day, your students should be finishing up the Solar Spectra Wavelength and Intensity Graph Lab. Provide ample opportunity for discussion within each student group and for a class debate after the students have completed the Lab.

DAY 7 AND 8:

These days can be used to finish up any remaining parts of the lesson plan that have not yet been covered. I have designed this lesson so that there can be a lot of flexibility. If you need more days to cover the background information or an extra day to allow students to present their ‘GO’ proposals or debate the type of elements present in the solar data, these two extra days were added for those specific needs.

DAY 9 AND 10:

Follow up lesson: "~Closing Lesson~" at the end of the power point presentation; 'Why is it important to study the Sun?' 'Effects of the Sun's activity on Earth.' 'And Why would we want to learn more about our Sun?' This portion of the lesson is designed for classroom discussion. Get the students involved, thinking and communitcating with one another.

Also, if you chose to do the KWL CHART lesson opener - listed below - part of your closing lesson can be filling in the 'L' portion of your chart. Helps students review what they have learned!