AST- 105 1st EditionLecture 9Outline of Last LectureI. Hydrostatic EquilibriumII. Nuclear FusionIII. Nuclear Energy SourceIV. Hydrogen FusionOutline of Current Lecture I. The Structure of the SunCurrent Lecture I. The Structure of the Suna. Atmosphere (outward)i. Photosphere- light sphere1. Source of most visible radiation from the Sun2. Typical temperature of the Sun is 5800 K3. Only a few hundred km thinka. This gives the Sun a “sharp” edge4. Absorbtion lines in solar spectrum arise in outer, cooler part of atmosphere.5. Contains support.ii. Chromosphere- color sphere1. Above photosphere2. Approximately 1500 km thick3. Low density gas4. Temperature reaches a minimum of 4500 K and then increases outward5. Visible during total solar eclipse6. Emits Hydrogren- a radiation- red color7. Contains spicules: jets of hot gas shooting outwardiii. Transition Zone1. Narrow region above chromospheres where temperature rises quickly about 10^6 K2. Energy to heat gas is transported outward by waves in the Sun’s magnetic field.3. Corona:a. A few million km thickb. Visible during a solar eclipsec. Very hot (1-2 x 10^6 K)d. Low density gase. Emits X-rays, also visible and UViv. Corona- outermost regionv. Solar
View Full Document
Unlocking...