The Sun and Stellar Structure 7/9/09. Astronomy 101

Transcription

1 The Sun and Stellar Structure 7/9/09 Astronomy 101

2 Astronomy Picture of the Day Astronomy 101

3 Something Cool: The Northern (and Southern) Lights Astronomy 101

4 Outline for Today Astronomy Picture of the Day Something Cool Business Return Lab 4 Q&A session Review of Light and Spectra The Sun More on Spectra? Minute Writing Break Lab 6 Astronomy 101

5 Some questions What is the difference between 'blackbody' and 'thermal' spectra? If we were to 'ship' out dangerous waste to the Sun would there be any negative impacts or would it burn away unnoticed? Why does plasma defice so many things? Like the result of fully ionizing a solid,s or the liquid part of blood, or scifi lasers? Astronomy 101

6 Blue Red The hotter star is the one on the A) right B) left Astronomy 101

7 Blue Red The hotter star is the one on the A) right B) left Astronomy 101

8 Blue Red The redder star is the one on the A) top B) middle C) bottom Astronomy 101

9 Blue Red The redder star is the one on the A) top B) middle C) bottom Astronomy 101

10 Appearent Brightnesses & Luminosities Star A is 8 times more luminous than star B. Star B is 3 times closer than star A. Which appears brighter? λ A) Star A λ B) Star B Astronomy 101

11 Appearent Brightnesses & Luminosities Star A is 8 times more luminous than star B. Star B is 3 times closer than star A. Which appears brighter? λ A) Star A λ B) Star B Astronomy 101

12 Which Will Result in an Emmission Spectrum? B C A D Astronomy 101

13 Which Will Result in an Emmission Spectrum? B C A D Astronomy 101

14 Questions for Today What is the Sun made of? How does the Sun support itself? Why does the Sun shine? What are the different layers of the Sun? What are Sun Spots? How are stellar spectra produced and what do they mean? Astronomy 101

15 What Is The Sun Made Of? Hydrogen, Helium, everything else Everything is (neutral or ionized) gas Astronomy 101

16 Temperature, Density, and Pressure Lower Temperature Higher Temperature Astronomy 101

17 Temperature, Density, and Pressure Mass density: Mass per volume (g/cm3) Number density: Atoms per volume (1/cm3) Low number density High number density Astronomy 101

18 Temperature, Density, and Pressure Force (per area) from atoms bouncing into each other and off the walls Astronomy 101

19 Temperature, Density, and Pressure How can we increase the pressure? λ Increase the temperature λ Increase the density λ Decrease the temperature λ Decrease the density Astronomy 101

20 Temperature, Density, and Pressure How can we increase the pressure? λ Increase the temperature λ Increase the density λ Decrease the temperature λ Decrease the density (P T) Astronomy 101

21 Density is Also Related to Temperature If you squeeze something, you are pushing the particles within it, which speeds them up

22 Gas Pressure keeps the Sun from collapsing Gravitational Equilibrium Pressure Gravity pulls mass inward Gravity Gas pressure pushes it out

23 Star A is twice as big as star B and twice as massive. Which will have a stronger gravitational force on their surface? A) Star A B) Star B

24 Star A is twice as big as star B and twice as massive. Which will have a stronger gravitational force on their surface? A) Star A B) Star B

25 Density, Pressure, and Temperature Increase Toward the Center Add graph

26 What Happens If the Some of the Energy Leaks Out? Hot gas Cool gas Temp of hot gas goes up B)Temp of hot gas goes down C)Nothing. A)

27 What Happens If the Some of the Energy Leaks Out? Hot gas Cool gas Temp of hot gas goes up B)Temp of hot gas goes down C)Nothing. A)

28 What Happens If the Hot Gas Cools Down? Hot gas Cool gas The Pressure: A)Goes Up B)Goes Down C)Shrinks The Star: D)Expands

29 What Happens If the Hot Gas Cools Down? Hot gas Cool gas The Pressure: A)Goes Up B)Goes Down C)Shrinks The Star: D)Expands

30 Energy Does Leak Out of the Sun (sunshine) Why Isn't the Sun Shrinking? Hot gas Cool gas There must be an energy source

31

32

33

34

35

36

37

38 Why is there no fusion in planets?

39 Oh the Sun is a Mass...

40

41

42

43

44

45

46

47

48

49

50 How can surface we of see below the the Sun?

51

52

53

54 Movie

55

56

57

58

59 HOT The spectral sequence in order COOL

60

61

62

63 Minute Writing List two questions you have on either the Sun or stellar structure. Astronomy 101

64 Assignments Read Chapters 15.2, 15.3, 17; Send Jeff and me two questions by Tuesday Read Lab 7; Send Jeff and me one question by Tuesday Lab 6 due Tuesday News article due on Tuesday Astronomy 101