Physics 202: Introduction to Astronomy

1
Physics 202 Introduction to Astronomy Lecture
13

• Carsten Denker
• Physics Department
• Center for SolarTerrestrial Research

2
The Sun

• The Solar Interior
• Mass
• Luminosity
• Radius
• Effective Temperature
• Surface Composition
• The Solar Atmosphere
• The Solar Cycle

3
Sun Overview
4
Evolution of the Sun and its Interior
Standard Solar Model X 0.71 ? 0.34 Y 0.27 ?
0.64
5
ppChain
Solar Neutrino Problem!
6
Interior Structure
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.
8
Differential Rotation and Magnetic Fields
9
Helioseismology
10
Photosphere
11
Sunspots Umbra and Penumbra
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!
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. 
14
Supergranulation
15
Photospheric Magnetic Fields
16
Sunspots Pores Filigree
17
Thin Flux Tube Model
18
Magnetic Carpet
19
Chromosphere
20
Mercury Transit November 15th,
1999
The images were taken 20 seconds apart from 2111
(first contact) to 2210 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.
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.
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.
23
Filament Eruption

• Ha Singer telescope
• Flat-field and limb darkening corrected
• Associated CME
• 28 June 2000
• 1800 2007 UT
• 120 frames
• 1 minute cadence
• 1 arcsec pixel-1
• 300 x 350 FOV

24
Sympathetic Flares
25
Transition Region Corona
26
Corona EIT 304 Å
27
Corona EIT 171 Å
28
Corona LASCO C2
29
Corona LASCO C3
30
Corona and Planets
31
Coronal Mass Ejection LASCO
32
Coronal Mass Ejection Comet
33
Coronal Mass Ejection TRACE
34
Space Weather
35
Space Weather Sun Earth
Connection
36
Space Weather Bow Shock
37
Space Weather Effects on Earth
38
Solar Cycle Butterfly Diagram
39
Solar Cycle
40
Solar Cycle Synoptic Map