Physics 202: Introduction to Astronomy – Lecture 13
Carsten Denker
Physics DepartmentCenter for Solar–Terrestrial
Research
March 10, 2006 Center for Solar-Terrestrial Research
The SunThe Solar Interior
Mass Luminosity Radius Effective Temperature Surface Composition
The Solar AtmosphereThe Solar Cycle
March 10, 2006 Center for Solar-Terrestrial Research
Sun – OverviewMass (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%
March 10, 2006 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
March 10, 2006 Center for Solar-Terrestrial Research
pp–Chain
Solar Neutrino Problem!
March 10, 2006 Center for Solar-Terrestrial Research
Interior Structure
March 10, 2006 Center for Solar-Terrestrial Research
Convection Condition
ln2.5
ln
d P
d T
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.
March 10, 2006 Center for Solar-Terrestrial Research
Differential Rotation and Magnetic Fields
March 10, 2006 Center for Solar-Terrestrial Research
Helioseismology
March 10, 2006 Center for Solar-Terrestrial Research
Photosphere
March 10, 2006 Center for Solar-Terrestrial Research
Sunspots – Umbra and Penumbra
March 10, 2006 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!
March 10, 2006 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.
March 10, 2006 Center for Solar-Terrestrial Research
Supergranulation
March 10, 2006 Center for Solar-Terrestrial Research
Photospheric Magnetic Fields
March 10, 2006 Center for Solar-Terrestrial Research
Sunspots – Pores & Filigree
March 10, 2006 Center for Solar-Terrestrial Research
Thin Flux Tube Model
March 10, 2006 Center for Solar-Terrestrial Research
Magnetic Carpet
March 10, 2006 Center for Solar-Terrestrial Research
Chromosphere
March 10, 2006 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.
March 10, 2006 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.
March 10, 2006 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) H – 0.6 Å filtergram, and (d) Ha center line filtergram.
March 10, 2006 Center for Solar-Terrestrial Research
Filament Eruption HSinger 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
March 10, 2006 Center for Solar-Terrestrial Research
Sympathetic Flares
March 10, 2006 Center for Solar-Terrestrial Research
Transition Region & Corona
March 10, 2006 Center for Solar-Terrestrial Research
Corona – EIT 304 Å
March 10, 2006 Center for Solar-Terrestrial Research
Corona – EIT 171 Å
March 10, 2006 Center for Solar-Terrestrial Research
Corona – LASCO C2
March 10, 2006 Center for Solar-Terrestrial Research
Corona – LASCO C3
March 10, 2006 Center for Solar-Terrestrial Research
Corona and Planets
March 10, 2006 Center for Solar-Terrestrial Research
Coronal Mass Ejection – LASCO
March 10, 2006 Center for Solar-Terrestrial Research
Coronal Mass Ejection & Comet
March 10, 2006 Center for Solar-Terrestrial Research
Coronal Mass Ejection – TRACE
March 10, 2006 Center for Solar-Terrestrial Research
Space Weather
March 10, 2006 Center for Solar-Terrestrial Research
Space Weather – Sun Earth Connection
March 10, 2006 Center for Solar-Terrestrial Research
Space Weather – Bow Shock
March 10, 2006 Center for Solar-Terrestrial Research
Space Weather Effects on Earth
March 10, 2006 Center for Solar-Terrestrial Research
Solar Cycle – Butterfly Diagram
March 10, 2006 Center for Solar-Terrestrial Research
Solar Cycle
March 10, 2006 Center for Solar-Terrestrial Research
Solar Cycle – Synoptic Map