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

March 10, 2006Center for Solar-Terrestrial Research The Sun  The Solar Interior Mass Luminosity Radius Effective Temperature Surface Composition  The Solar Atmosphere  The Solar Cycle

March 10, 2006Center 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) Mean density (gm/cm 3 )1.410 Rotational period (days)25-36 Escape velocity (km/sec) 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% % % % % % %

March 10, 2006Center 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, 2006Center for Solar-Terrestrial Research pp–Chain Solar Neutrino Problem!

March 10, 2006Center for Solar-Terrestrial Research Interior Structure

March 10, 2006Center 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.

March 10, 2006Center for Solar-Terrestrial Research Differential Rotation and Magnetic Fields

March 10, 2006Center for Solar-Terrestrial Research Helioseismology

March 10, 2006Center for Solar-Terrestrial Research Photosphere

March 10, 2006Center for Solar-Terrestrial Research Sunspots – Umbra and Penumbra

March 10, 2006Center 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, 2006Center 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, 2006Center for Solar-Terrestrial Research Supergranulation

March 10, 2006Center for Solar-Terrestrial Research Photospheric Magnetic Fields

March 10, 2006Center for Solar-Terrestrial Research Sunspots – Pores & Filigree

March 10, 2006Center for Solar-Terrestrial Research Thin Flux Tube Model

March 10, 2006Center for Solar-Terrestrial Research Magnetic Carpet

March 10, 2006Center for Solar-Terrestrial Research Chromosphere

March 10, 2006Center 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, 2006Center 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, 2006Center for Solar-Terrestrial Research Filament Evolution Temporal evolution in H  center line of a sigmoidal filament in active region NOAA 8668 during August (a) Videomagnetogram, (b) CaI line wing filtergram, (c) H  – 0.6 Å filtergram, and (d) Ha center line filtergram.

March 10, 2006Center for Solar-Terrestrial Research Filament Eruption  H  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

March 10, 2006Center for Solar-Terrestrial Research Sympathetic Flares

March 10, 2006Center for Solar-Terrestrial Research Transition Region & Corona

March 10, 2006Center for Solar-Terrestrial Research Corona – EIT 304 Å

March 10, 2006Center for Solar-Terrestrial Research Corona – EIT 171 Å

March 10, 2006Center for Solar-Terrestrial Research Corona – LASCO C2

March 10, 2006Center for Solar-Terrestrial Research Corona – LASCO C3

March 10, 2006Center for Solar-Terrestrial Research Corona and Planets

March 10, 2006Center for Solar-Terrestrial Research Coronal Mass Ejection – LASCO

March 10, 2006Center for Solar-Terrestrial Research Coronal Mass Ejection & Comet

March 10, 2006Center for Solar-Terrestrial Research Coronal Mass Ejection – TRACE

March 10, 2006Center for Solar-Terrestrial Research Space Weather

March 10, 2006Center for Solar-Terrestrial Research Space Weather – Sun Earth Connection

March 10, 2006Center for Solar-Terrestrial Research Space Weather – Bow Shock

March 10, 2006Center for Solar-Terrestrial Research Space Weather Effects on Earth

March 10, 2006Center for Solar-Terrestrial Research Solar Cycle – Butterfly Diagram

March 10, 2006Center for Solar-Terrestrial Research Solar Cycle

March 10, 2006Center for Solar-Terrestrial Research Solar Cycle – Synoptic Map