Infrared Astronomy and Activities Dan Burns Los Gatos High School Lawrence Livermore National Lab

1. Invisible Waves Infrared Astronomy and Activities Dan Burns Los Gatos High School Lawrence Livermore National Lab dburns@lgsuhsd.org

2. http://education.llnl.gov/academies/?page=home

3. Overview • What is Infrared Radiation (IR)? • Discovery of IR • IR Astronomy • IR Observatories • Classroom Activities NASA/JPL-Caltech

4. IR Characteristics • IR is bounded by Visible Light and Microwave Radiation • Wavelengths from about 0.7 to 350 microns • Primary Source is Thermal Radiation • Humans can sense it with nerves in skin • Snakes can “see” IR with Pits (Pit Vipers) NASA/JPL-Caltech

5. Thermal Radiation • Emitted by materials with relatively strong molecular or atomic bonds (ie solids and liquids) • Every object with a T > 0 K emits thermal radiation • Produced by random motions of charged particles • Radiation peak, usually in IR, can be used to determine temperature NASA/JPL-Caltech NASA/JPL-Caltech NASA/JPL-Caltech

6. William Herschel • German Immigrant to England • Discovered Uranus in 1781 • Catalogued Night Sky with Sister Caroline • Discovered IR in 1800 NASA/JPL-Caltech

7. Herschel’s IR Experiment • Investigated heat of colors in spectrum • Temperature increased from violet to red • Placed a thermometer beyond red, this measured greatest temperature increase http://www.sciencemuseum.org.uk/on-line/treasure/objects/1876-565.asp

8. Student Herschel Experiment • Materials: Copy Paper Box, Smaller Box, White Paper, Tape, Equilateral Glass Prism, Black Paint, Timer, 3 Thermometers, Sunlight! • Time Required: ~ 30 minutes NASA/JPL-Caltech

9. Equipment Setup NASA/JPL-Caltech NASA/JPL-Caltech • Paint Thermometer Bulbs Black • Trim and Tape Thermometers Close Together • Cut Opening for Prism and Mount it • Tape White Sheet of Paper to Bottom of box

10. Procedure Outline NASA/JPL-Caltech NASA/JPL-Caltech NASA/JPL-Caltech • Position Box and Prism so Spectrum Shows • Record Shade Temperature • Place Thermometers, 1 each in Blue, Yellow, and IR • Record Temperatures at 1 minute intervals for 5 minutes

11. Typical Results NASA/JPL-Caltech

12. Why Infrared Astronomy? • Almost Everything Emits IR • IR Passes Through Dust • Exoplanets Easier to Detect in IR • Distant Object’s Visible Light Redshifted • Important Molecular Spectra in IR Credit: ESA/ISO, SWS, A.F.M. Moorwood

13. IR Reveals the Invisible NASA/JPL-Caltech Interstellar Dust Emits IR

14. Spitzer Shows a Warped Sombrero Galaxy http://www.spitzer.caltech.edu/Media/mediaimages/index.shtml

15. Spitzer Reveals Stars and the Galloping Ghoul http://www.spitzer.caltech.edu/Media/mediaimages/index.shtml

16. IR Uncovers What is Hidden Visible Spitzer Space Telescope Reveals Star Formation in DR21 IR NASA/JPL-Caltech

17. Spitzer Zooms into the Triffid Nebula http://www.spitzer.caltech.edu/Media/mediaimages/index.shtml

18. IR Discovers Dim Objects UK IR Telescope Discovers Brown Dwarfs and Potential Free-Floating Planets in Orion Image courtesy of the U.K. Infrared Telescope, Mauna Kea Observatory, Hawaii

19. IR Detects Distant Objects Visible Light from Very Distant Galaxies is Redshifted to IR

20. Important Molecular Spectral Lines are in IR IR Space Observatory Reveals Water Molecules being Produced in Orion Nebula

21. Spitzer Detects Structures in Polycyclic Aromatic Hydrocarbon Dust http://www.spitzer.caltech.edu/Media/mediaimages/index.shtml

22. Detecting IR • Near, Mid, and Far IR • Atmospheric Absorption • IR Observatories NASA/JPL-Caltech Image courtesy of the U.K. Infrared Telescope, Mauna Kea Observatory, Hawaii

23. Near, Mid, and Far IR Bands NASA/JPL-Caltech Visible Near Mid NASA/JPL-Caltech

24. Atmosphere Impedes IR Observation • Water Vapor Absorbs Some IR Wavelengths • Atmosphere Emits its own IR Radiation NASA/JPL-Caltech

25. Past, Present, and Future IR Observatories HST ESA Herschel NASA/STScI IRAS NASA/JPL-Caltech Infrared Processing and Analysis Center, Caltech/JPL. IPAC is NASA's Infrared Astrophysics Data Center SST UKIRT NASA/JWST Image courtesy of the U.K. Infrared Telescope, Mauna Kea Observatory, Hawaii SOFIA NASA/USRA

26. Student Activities • Herschel Experiment • IR Photo Album • Solar Cell IR Detector • Near IR Digital Camera • IR Detection Cards • Red Tide Spectrometer with LabQuest

27. IR Photo Album Resources http://spaceplace.jpl.nasa.gov/en/kids/sirtf1/sirtf_action.shtml for activity

28. Cool Cosmos Website http://coolcosmos.ipac.caltech.edu/videos/more_than_your/index.html

29. Herschel Experiment Resources • http://coolcosmos.ipac.caltech.edu/cosmic_classroom/classroom_activities/herschel_experiment.html for detailed activity • www.sciencekit.com for prism (catalog # WW65664M00 $8.95) and thermometers (catalog #6638910 $13.25 for 10-Pack)

30. Solar Cell IR Detector Resources • www.radioshack.com for Mini Audio Amplifier (Catalog # 2771008 $14.99), Solar Cell (Catalog # 277-1201 $13.99), • 6’ Cable (Catalog # 42-2420 $3.29) • http://www.sofia.usra.edu/Edu/materials/activeAstronomy/activeAstronomy.html for detailed activity information

31. Near IR Digital Camera • Webcams, Digital Cameras, or Camcorders • Remove IR Blocking Filter from CCD • Install IR only pass filter (Wratten 87c, exposed color negative, or floppy disk) • Reassemble and view the world in Near IR • Sony Nightshot Camcorder has switch to remove IR blocking filter

32. IR Filter Spectral Characteristics

33. IR Detection Cards • 2 Types of Materials can Produce Visible Light When Exposed to IR from a Remote Control • Anti-Stokes Material Absorbs 2 or More Photons for Every Visible Photon Emitted • Phosphorescent Material Must be Exposed to Visible Light First • See Activity from KSU Physics Education Group

34. Anti-Stokes Model Phosphorescent Model

35. Red Tide and SpectroVis Spectrometers • Red Tide and SpectroVis Spectrometers by Vernier • Automatically reads the wavelength calibration coefficients of the spectrometer and configures operating software • USB to PC or Mac interface; no external power requirements • The Red Tide starts at $1732, SpectroVis at $449 • Optical Fibers are extra

36. IR Emission from a Green Laser • Some Green Lasers allow IR at 802 nm and 1064 nm to leak out • If IR reflects off surfaces that pass green it can be dangerous • This IR can be measured with a simple experiment, see below for more info: http://www.nist.gov/customcf/get_pdf.cfm?pub_id=906138

37. California Science Standards • Earth Science 2d: Students know that stars differ in their life cycles and that visual, radio, and X-ray telescopes may be used to collect data that reveal those differences. • Physics 4e: Students know radio waves, light, and X-rays are different wavelength bands in the spectrum of electromagnetic waves. • Chemistry 1i, 1j Students know the experimental basis for the development of the quantum theory of atomic structure and the historical importance of the Bohr model of the atom. Students know that spectral lines are the result of transitions of electrons between energy levels and that these lines correspond to photons with a frequency related hv). to the energy spacing between levels by using Planck’s relationship