1. NJIT Physics 320: Astronomy and Astrophysics – Lecture X Carsten Denker Physics Department Center for Solar–Terrestrial Research

2. November 5th, 2003NJIT Center for Solar-Terrestrial Research Problem 9.9

3. November 5th, 2003NJIT Center for Solar-Terrestrial Research Problem 9.12 At wavelength where the opacity is greatest, the value of s is smallest. If the temperature of the star’s atmosphere increases outward, than a smaller value of s corresponds to looking at a higher temperature and a brighter gas. At wavelength where the opacity is greatest, you would therefore emission lines.

4. November 5th, 2003NJIT Center for Solar-Terrestrial Research Problem 9.13 A large hollow spherical shell of hot gas will look like a ring if you can see straight through the middle of the shell. That is, the shell must be optically thin, and an optically thin hot gas produces emission lines. Near the edges of the shell, where your line of sight passes through more gas, the shell appears brighter and you see in a ring. In 1992 a tremendous explosion occurred in the constellation of Cygnus. Dubbed Nova Cygni 1992. Astronomers hypothesize that this system's white dwarf had so much gas dumped onto it's surface that conditions became ripe for nuclear fusion. The resulting thermonuclear detonation blasted much of the surrounding gas into an expanding shell.

5. November 5th, 2003NJIT Center for Solar-Terrestrial Research Exhibition Title Contest  Ian  Journey to the Center of our/your Universe  Voyage to the Center of our Solar System  The Sun: More than a Reason to Skip Class  Our Sun: What can it do for you?  Brick City Sun  The Key to Live on Earth: The Sun  Our Sun: The Orb of Life  The Giant Nuclear Reactor: The Sun  John  The Sun: Our Closest Star  The Sun: A Look inside our Closest Star  Gerardo, Matthew, & Mike  Sunbelievable Solar Sciene

6. November 5th, 2003NJIT Center for Solar-Terrestrial Research The Sun  The Solar Interior  Mass  Luminosity  Radius  Effective Temperature  Surface Composition  The Solar Atmosphere  The Solar Cycle

7. November 5th, 2003NJIT Center for Solar-Terrestrial Research Sun – Overview Mass (kg)1.989e+30 Mass (Earth = 1)332,830 Equatorial radius (km)695,000 Equatorial radius (Earth = 1)108.97 Mean density (gm/cm 3 )1.410 Rotational period (days)25-36 Escape velocity (km/sec)618.02 Luminosity (ergs/sec)3.827e33 Magnitude (Vo)-26.8 Mean surface temperature6,000°C Age (billion years)4.5 Principal chemistry Hydrogen Helium Oxygen Carbon Nitrogen Neon Iron Silicon Magnesium All others 92.1% 7.8% 0.061% 0.030% 0.0084% 0.0076% 0.0037% 0.0031% 0.0024% 0.0030%

8. November 5th, 2003NJIT Center for Solar-Terrestrial Research Evolution of the Sun and its Interior Standard Solar Model: X: 0.71  0.34 Y: 0.27  0.64 Sun–Earth Connection?

9. November 5th, 2003NJIT Center for Solar-Terrestrial Research pp–Chain Solar Neutrino Problem!

10. November 5th, 2003NJIT Center for Solar-Terrestrial Research Interior Structure

11. November 5th, 2003NJIT Center for Solar-Terrestrial Research Convection Condition The Sun is purely radiative below r/R  = 0.71 and becomes convective above that point. Physically this occurs because the opacity in the outer layers of the Sun becomes large enough to inhibit the transport of energy.

12. November 5th, 2003NJIT Center for Solar-Terrestrial Research Differential Rotation and Magnetic Fields

13. November 5th, 2003NJIT Center for Solar-Terrestrial Research Helioseismology

14. November 5th, 2003NJIT Center for Solar-Terrestrial Research Photosphere

15. November 5th, 2003NJIT Center for Solar-Terrestrial Research Sunspots – Umbra and Penumbra

16. November 5th, 2003NJIT Center for Solar-Terrestrial Research Active Regions Active region 9169 was the host of the largest sunspot group observed so far during the current solar cycle. On 20 September 2000, the sunspot area within the group spanned 2,140 millionths of the visible solar surface, an area a dozen times larger than the entire surface of the Earth!

17. November 5th, 2003NJIT Center for Solar-Terrestrial Research Spectrum of Granulation “Wiggly” spectral lines in the solar photosphere inside and outside a region of activity, reflecting rising and sinking motions in granulation. Over the central one third of the spectrogram height, the slit crossed a magnetically active region. Here, the velocity amplitudes are much reduced, demonstrating how convection is disturbed in magnetic areas.

18. November 5th, 2003NJIT Center for Solar-Terrestrial Research Model of Convection 3D animation of convection. The animation shows temperature fluctuations in a layer of unstable, turbulent gas. (Courtesy of Andrea Malagoli, University of Chicago)

19. November 5th, 2003NJIT Center for Solar-Terrestrial Research Supergranulation

20. November 5th, 2003NJIT Center for Solar-Terrestrial Research Photospheric Magnetic Fields

21. November 5th, 2003NJIT Center for Solar-Terrestrial Research Sunspots – Pores & Filigree

22. November 5th, 2003NJIT Center for Solar-Terrestrial Research Thin Flux Tube Model

23. November 5th, 2003NJIT Center for Solar-Terrestrial Research Magnetic Carpet

24. November 5th, 2003NJIT Center for Solar-Terrestrial Research Chromosphere

25. November 5th, 2003NJIT Center for Solar-Terrestrial Research Mercury Transit November 15th, 1999 The images were taken 20 seconds apart from 21:11 (first contact) to 22:10 UT (last contact). The image were captured with a Kodak MegaPlus 4.2 CCD camera. The spatial resolution is about 1  per pixel. Here, we show only a small portion of the full disk images near the solar north pole. The field of view is approximately 470   170  or 340,000 km  125,000 km on the Sun.

26. November 5th, 2003NJIT Center for Solar-Terrestrial Research Prominences The SoHO EIT full sun image, taken on 14 September 1999 in the He II line at 304 Å shows the upper chromosphere/lower transition region at a temperature of about 60,000 K. The bright features are called active regions. A huge erupting prominence escaping the Sun can be seen in the upper right part of the image. Prominences are “cool” 60,000 K plasma embedded in the much hotter surrounding corona, which is typically at temperatures above 1 million K.

27. November 5th, 2003NJIT Center for Solar-Terrestrial Research Filament Evolution Temporal evolution in H  center line of a sigmoidal filament in active region NOAA 8668 during August 2000. (a) Videomagnetogram, (b) CaI line wing filtergram, (c) Ha – 0.6 Å filtergram, and (d) Ha center line filtergram.

28. November 5th, 2003NJIT Center for Solar-Terrestrial Research Filament Eruption

29. November 5th, 2003NJIT Center for Solar-Terrestrial Research Sympathetic Flare

30. November 5th, 2003NJIT Center for Solar-Terrestrial Research Transition Region & Corona

31. November 5th, 2003NJIT Center for Solar-Terrestrial Research Corona – EIT 304 Å

32. November 5th, 2003NJIT Center for Solar-Terrestrial Research Corona – EIT 171 Å

33. November 5th, 2003NJIT Center for Solar-Terrestrial Research Corona – LASCO C2

34. November 5th, 2003NJIT Center for Solar-Terrestrial Research Corona – LASCO C3

35. November 5th, 2003NJIT Center for Solar-Terrestrial Research Corona and Planets

36. November 5th, 2003NJIT Center for Solar-Terrestrial Research Coronal Mass Ejection – LASCO

37. November 5th, 2003NJIT Center for Solar-Terrestrial Research Coronal Mass Ejection & Comet

38. November 5th, 2003NJIT Center for Solar-Terrestrial Research Coronal Mass Ejection – TRACE

39. November 5th, 2003NJIT Center for Solar-Terrestrial Research Space Weather

40. November 5th, 2003NJIT Center for Solar-Terrestrial Research Space Weather – Sun Earth Connection

41. November 5th, 2003NJIT Center for Solar-Terrestrial Research Space Weather – Bow Shock

42. November 5th, 2003NJIT Center for Solar-Terrestrial Research Space Weather Effects on Earth

43. November 5th, 2003NJIT Center for Solar-Terrestrial Research Solar Cycle – Butterfly Diagram

44. November 5th, 2003NJIT Center for Solar-Terrestrial Research Solar Cycle

45. November 5th, 2003NJIT Center for Solar-Terrestrial Research Solar Cycle – Synoptic Map

46. November 5th, 2003NJIT Center for Solar-Terrestrial Research Big Bear Solar Observatory

47. November 5th, 2003NJIT Center for Solar-Terrestrial Research Telescopes and Control Room

48. November 5th, 2003NJIT Center for Solar-Terrestrial Research BBSO – Instruments

49. November 5th, 2003NJIT Center for Solar-Terrestrial Research Optical Lab and Parallel Computer

50. November 5th, 2003NJIT Center for Solar-Terrestrial Research Homework Class Project  Continue improving the PPT presentation.  Use the abstract from the previous assignment as a starting point for a PowerPoint presentation.  The PPT presentation should have between 5 and 10 slides.  Bring a print-out of the draft version to the next class as a discussion template for group work  Homework is due Wednesday November 12 th, 2003 at the beginning of the lecture!  Exhibition name competition!

51. November 5th, 2003NJIT Center for Solar-Terrestrial Research Homework  Homework is due Wednesday November 12 th, 2003 at the beginning of the lecture!  Homework assignment: Problems 11.1, 11.2, and 11.8!  Late homework receives only half the credit!  The homework is group homework!  Homework should be handed in as a text document!