1. Studying the sun
Chapter 24.1
SC912N11, SC912E58
SC.912.P.10.16/18,

2. Objectives
Describe the waves that compose the electromagnetic spectrum
Describe what the different types of spectra reveal about stars
Explain how the Doppler effect is applies to the motion of stars in relation to Earth.

3. Essential Questions
What types of radiation make up the electromagnetic spectrum?
How do scientist determine the elements in a star?

4. Vocabulary Words Electromagnetic spectrum Photon Spectroscopy
Continuous spectrum
Absorption spectrum
Emission spectrum
Doppler Effect

5. Electromagnetic Radiation
Electromagnetic radiation includes gamma rays, X-rays, ultraviolet light, visible light, infrared light, microwaves, and radio waves.
The arrangement of these waves according to their wavelengths and frequencies is called the electromagnetic spectrum.
All energy, travels through the vacuum of space at the speed of light, or 300,000 kilometers per second.
Over a 24 hour day, this equals 26 billion kilometers.
Stars and other bodies in space emit light that can be used to study them.
Light is only a small part of the different types of energy known as electromagnetic radiation.
Nothing is faster than the speed of light in the vacuum.

6. Waves Measured from crest to crest
Vary in size from kilometers to less than a billionth of a centimeter

7. Colors and Wavelengths

8. Photons A stream of particles Resemble bullets fired from machine gun.
Push on matter.
Shorter wavelengths have more energetic photons.
Blue light has more than red light.

9. Spectroscopy
Developed by Sir Isaac Newton when he divided light into components.

10. Spectroscopy
Spectroscopy is the study of the properties of light that depend on wavelength.
Newton produced a rainbow of colors which included all wavelengths of visible light.

11. Spectroscopy Continuous Spectrum Absorption Spectrum
Produced by an incandescent solid, liquid, or gas under high pressure.
Incandescent means to emit light when hot.
Spectrum consists of an uninterrupted band of color.
Visible light from light bulb is a result
Produced when visible light is passed through a relatively cool gas under low pressure.
Appears continuous, but has a series of dark lines running through it.
The radiation most stars produce.

12. Spectroscopy

13. Emission Spectrum Produced by a hot gas under low pressure.
A series of bright lines of particular wavelengths (depending on gas)
When the spectrum of a star is studied, the spectral lines act as “fingerprints.” These lines identify the elements present and thus the star’s chemical composition.
The spectra of most stars are of the dark-line, or absorption type.
The importance of these spectra is that each element or compound in its gaseous form produces a unique set of lines.
The spectrum of the sun contains thousands of dark lines.
More than 60 elements have been identified by matching these lines with those of known elements on Earth.

14. What is spectroscopy?
Who introduced the field of spectroscopy?

15. Doppler Effect
Refers to the perceived change in wave length of a wave that is emitted from a source that is moving away or toward an object.
Tells astronomers whether a star is moving towards or away from Earth.

16. Essential Questions
What types of radiation make up the electromagnetic spectrum?
How do scientist determine the elements in a star?

17. Savage Sun Movie Part 1 (25 min)
Cooler, darker spots on sun are called___________
Squeezing together of H atoms to create He is ____________
H atoms ripped apart, create electrically charged particles called ______________
How is the sun similar to a bar magnet on Earth?

19. Tools for studying space
Ch.24.2
SC.912.N.1.1,
SC.912.E.5.7, SC.912.E.5.8

20. Objectives
Explain how refracting, reflecting, and radio telescopes work.
Explain the advantages that space telescopes have over Earth-based telescopes.

21. Vocabulary Refracting telescope Chromatic aberration
Reflecting telescope
Radio telescope
Interferometer
Resolving Power

23. Essential Questions How does a refracting telescope produce an image?
What advantage does the space telescopes have over the Earth-based telescopes?

24. Refracting Telescopes
Galileo considered first person to use a telescope for astronomical observations.
Uses a lens to bend or refract light
Most important lens in a refracting telescope, the objective lens, produces an image by bending light from a distant object so that the light converges at an area called the focus
Focus = central point

25. Refracting Telescopes
How it works is that light from an object enters the telescope and passes through the objective lens, which bends the light rays so that they converge at the focus. The rays then travel to the eyepiece, which magnifies the image for the observer.

26. Chromatic Aberration
Chromatic (chroma = color) aberration (aberrare = to go astray)
Optical defect, short wavelengths bend more so than long wavelengths of refracting telescopes
When a refracting telescope is in focus for red light, blue and violet light are out of focus.
Problem for astronomers because it weakens the image and produces a halo of color around it.

27. Reflecting Telescope
Use a concave mirror that focuses light in front of a mirror, rather than behind it, like the lens.

28. Resolving Power
Is a telescopes ability to produce sharper images and finer detail.

29. Properties of Optical telescopes
Both reflecting and refracting telescopes have 3 properties that aid astronomers:
Light-gathering power
Resolving power
Magnifying power

30. Radio Telescopes Are huge dishes used to gather and focus radio waves
A radio telescope focuses the incoming radio waves on an antenna, which absorbs and transmits these waves to an amplifier, just like a radio antenna.
Used to measure the galactic distribution of hydrogen
Radio telescopes have poor resolution, when grouped reduces problem.
Several radio telescopes wired together, is called an interferometer.
Measure the galaxy’s distribution of hydrogen from which stars are made from.

31. Advantage
Major advantage of space telescopes versus Earth-based telescopes is they do not have interference from the atmosphere.

32. Essential Questions How does a refracting telescope produce an image?
What advantage does the space telescopes have over the Earth-based telescopes?

33. BINGO GAME
Create a Bingo Board using the vocabulary words provided in the chapter.
4 x 4

34. Ch. 24.2 SC912N11, SC912N14, SC912N24, SC912N25, SC912N41 SC912E54
The Sun
Ch. 24.2
SC912N11, SC912N14, SC912N24, SC912N25, SC912N41
SC912E54

35. Objectives Explain the structure of the sun.
Explain how the sun produces energy.

36. Essential Questions What is the structure of the sun?
How does the sun produce energy?

37. Structure of the Sun We can divide the sun into four parts:
The solar interior
The visible surface or photosphere
2 atmospheric layers –chromosphere
corona

38. Photosphere Photo = light sphere = a ball
Radiates most of the sunlight we see and thought to be the “visible” surface
Grainy texture is the result
of numerous relatively small,
bright markings called
granules, which are
surrounded by narrow,
dark regions.

39. Photosphere/granules
Granules are normally the size of Texas
Owe brightness to hotter gases that are rising from below. As gas spreads, cooling causes it to darken and sink back into the interior.
Each one only survives for minutes
The combined motion of new granules replacing old ones gives the photosphere the appearance of boiling.

40. Photosphere/granules
The up and down movement is called convection.
Convection is responsible for the transfer of energy in the uppermost part of the sun’s interior.
Energy is transmitted inside the sun through the processes of radiation and convection.
The sun’s energy is created in and around the core.

41. Photosphere -revealed by dark lines of its absorption spectrum.
-90% of suns surface atoms are hydrogen, almost 10% helium

42. Chromosphere
Lies just above the photosphere
Relatively thin layer of hot gases a few thousand kilometers thick.
Only observed during solar eclipses or with special instruments

43. corona Corona = crown Outer most portion of the solar atmosphere
Only visible when the brilliant photosphere is covered.
Outer fringe, ionized gases have speeds great enough to escape the gravitational pull of the sun.
The streams of protons and electrons that flow from the corona constitute the solar wind.

44. Sun Spots Dark regions on the surface of the photosphere
An individual spot contains a black center rimmed by lighter region.
Sunspots appear dark because of their temperature, which is about 1500 K less than that of the surrounding solar surface. They are cooler than the rest of the surface.
Sunspots increase and decrease in a cycle of 11 years.

45. Sun Spots

46. Solar Flares Most explosive event associated with sunspots
Are brief outbursts that normally last about an hour and appear as a sudden brightening of the region above a sunspot cluster.
During their existence, solar flares release enormous amounts of energy, much of it in the form of ultraviolet, radio, and X-ray radiation.

47. Solar Flares
Most spectacular effects of solar flares on Earth, are the auroras, also called northern and southern lights.

49. Nuclear Fusion The process in which the sun produces energy.
The nuclear reaction converts four hydrogen nuclei into the nucleus of a helium atom.
During nuclear fusion, energy is released because some matter is actually converted to energy.

50. Nuclear Fusion
The sun consumes an estimated 600 million tons of hydrogen each second
About 400 million tons are converted to energy.
As hydrogen is consumed, the product of this reaction-helium-forms the solar core, which continually grows in size.
The sun’s energy is created in the area in and around its core.

51. The Sun
In the stable present stage the sun is expected to exist 10 billion years.
The sun is 4.5 billion years old.
“Middle-Aged”
It has 5.5 billion years left at present stage.

52. Essential Questions What is the structure of the sun?
How does the sun produce energy?

53. Chandra X-Ray Observatory
Studies black holes.

54. Savage Sun Part 2 Quiz
Streams of particles coming out of sun that disrupt communications on Earth are
What forms when electrons from the solar wind cascade down Earths magnetic field lines and interact with gases in Earth’s atmosphere?
What part of the sun can a person on Earth observe during a solar eclipse?
At the Solar Neutrino Observatory, what is used to capture neutrinos?

55. Savage Sun Movie
Part 2 (25 min)

57. Savage Sun Movie Quiz
You may use your notes from Part One and Part Two to complete the quiz. This is an individual assignment. No talking or sharing of answers. Anyone who talks will receive a 0% on the quiz.