genral astronomy
2. Describe the three main layers of the solar atmo-
sphereand how you would best observe them.
7. How do astronomers detect the presence of a
magnetic field in hot gases, such as the field in the solar
photosphere?
12. Why do thermonuclear reactions in the Sun take
placeonly in its core?
The Temperatures of Stars
.
3. .Measurements of a binary star system are required
todetermine what property of stars? a. Luminosity,
b. Apparent magnitude, c. distance, d. mass, e. temperature
10. whatis the difference between apparent magni-
tude and absolute magnitude?
20. Draw an H-R diagram and sketch the regions
occupied by main-sequence stars, giants, supergiant’s,
andwhite dwarfs. Briefly discuss the different ways you
couldhave labeled the axes of your graph.
3. What is the source of energy that enables a main-
Sequence star to shine? a. Friction between its atoms,
b. Fusion of hydrogen in a shell that surrounds the
Core, c. Fusion of helium in its core, d. Fusion of hydro-
Genin its core, e. Burning on its surface
.
6. whydo thermonuclear reactions not occur on the
Surface of a main-sequence star?
13.What does it mean when an astronomer says that
astar “moves” from one place to another on an H-R
Diagram?
3. What prevents a neutron star from collapsing?
a. Hydrogen fusion, b. friction, c. electron degeneracy
Pressure, d. neutron degeneracy pressure, e. helium fusion
7. whatis a planetary nebula, and how does it form?
12.What is the Oppenheimer-Volkov limit?
3 .which feature is found with Kerr black holes but not Schwarzschild black holes? a. a singularity, b. an event horizon, c. gravitational redshift of photons outside of the black hole, d. an ergo region, e. warping of nearby space time
10. If light cannot escape from a black hole, how can we detect X rays from such an object?
