Physics 202: Introduction to Astronomy – Lecture 13

1. Physics 202: Introduction to Astronomy – Lecture 13 Carsten Denker Physics Department Center for Solar–Terrestrial Research

2. The Sun • The Solar Interior • Mass • Luminosity • Radius • Effective Temperature • Surface Composition • The Solar Atmosphere • The Solar Cycle Center for Solar-Terrestrial Research

3. Mass (kg) 1.989e+30 Mass (Earth = 1) 332,830 Equatorial radius (km) 695,000 Equatorial radius (Earth = 1) 108.97 Mean density (gm/cm3) 1.410 Rotational period (days) 25-36 Escape velocity (km/sec) 618.02 Luminosity (ergs/sec) 3.827e33 Magnitude (Vo) -26.8 Mean surface temperature 6,000°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% Sun – Overview Center for Solar-Terrestrial Research

4. Evolution of the Sun and its Interior Standard Solar Model: X: 0.71  0.34 Y: 0.27  0.64 Center for Solar-Terrestrial Research

5. pp–Chain Solar Neutrino Problem! Center for Solar-Terrestrial Research

6. Interior Structure Center for Solar-Terrestrial Research

7. 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. Center for Solar-Terrestrial Research

8. Differential Rotation and Magnetic Fields Center for Solar-Terrestrial Research

9. Helioseismology Center for Solar-Terrestrial Research

10. Photosphere Center for Solar-Terrestrial Research

11. Sunspots – Umbra and Penumbra Center for Solar-Terrestrial Research

12. 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! Center for Solar-Terrestrial Research

13. 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. Center for Solar-Terrestrial Research

14. Supergranulation Center for Solar-Terrestrial Research

15. Photospheric Magnetic Fields Center for Solar-Terrestrial Research

16. Sunspots – Pores & Filigree Center for Solar-Terrestrial Research

17. Thin Flux Tube Model Center for Solar-Terrestrial Research

18. Magnetic Carpet Center for Solar-Terrestrial Research

19. Chromosphere Center for Solar-Terrestrial Research

20. 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. Center for Solar-Terrestrial Research

21. 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. Center for Solar-Terrestrial Research

22. 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) H – 0.6 Å filtergram, and (d) Ha center line filtergram. Center for Solar-Terrestrial Research

23. Filament Eruption • Ha Singer telescope • Flat-field and limb darkening corrected • Associated CME • 28 June 2000 • 18:00 – 20:07 UT • 120 frames • 1 minute cadence • 1 arcsec pixel-1 • 300” x 350” FOV Center for Solar-Terrestrial Research

24. Sympathetic Flares Center for Solar-Terrestrial Research

25. Transition Region & Corona Center for Solar-Terrestrial Research

26. Corona – EIT 304 Å Center for Solar-Terrestrial Research

27. Corona – EIT 171 Å Center for Solar-Terrestrial Research

28. Corona – LASCO C2 Center for Solar-Terrestrial Research

29. Corona – LASCO C3 Center for Solar-Terrestrial Research

30. Corona and Planets Center for Solar-Terrestrial Research

31. Coronal Mass Ejection– LASCO Center for Solar-Terrestrial Research

32. Coronal Mass Ejection & Comet Center for Solar-Terrestrial Research

33. Coronal Mass Ejection – TRACE Center for Solar-Terrestrial Research

34. Space Weather Center for Solar-Terrestrial Research

35. Space Weather – Sun Earth Connection Center for Solar-Terrestrial Research

36. Space Weather – Bow Shock Center for Solar-Terrestrial Research

37. Space Weather Effects on Earth Center for Solar-Terrestrial Research

38. Solar Cycle – Butterfly Diagram Center for Solar-Terrestrial Research

39. Solar Cycle Center for Solar-Terrestrial Research

40. Solar Cycle – Synoptic Map Center for Solar-Terrestrial Research