Concept explainers
Why do you suppose so great a fraction of the Sun’s energy comes from its central regions? Within what fraction of the Sun’s radius does practically all of the Sun’s luminosity originate (see Figure 16.16)? Within what radius of the Sun has its original hydrogen been partially used up? Discuss what relationship the answers to these questions bear to one another.
Figure 16.16 shows how the temperature, density, rate of energy generation, and composition vary from the center of the Sun to its surface.
Want to see the full answer?
Check out a sample textbook solutionChapter 16 Solutions
Astronomy
Additional Science Textbook Solutions
College Physics: A Strategic Approach (4th Edition)
Physics for Scientists and Engineers with Modern Physics
Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (4th Edition)
Conceptual Physics (12th Edition)
Modern Physics
Conceptual Integrated Science
- Let's examine how we know that the Sun cannot power itself by chemical reactions. Using the fact that an average chemical reaction between two atoms releases 1.6×10-19 J of energy, estimate how long the Sun could emit energy at its current luminosity. Compare that estimate to the known age of Earth.arrow_forwardWhat is the average density of the Sun? How does it compare to the average density of Earth?arrow_forwardFrom the information in Figure 15.21, estimate the speed with which the particles in the CME in parts (c) and (d) are moving away from the Sun. Figure 15.21 Flare and Coronal Mass Ejection. This sequence of four images shows the evolution over time of a giant eruption on the Sun. (a) The event began at the location of a sunspot group, and (b) a flare is seen in far-ultraviolet light. (c) Fourteen hours later, a CME is seen blasting out into space. (d) Three hours later, this CME has expanded to form a giant cloud of particles escaping from the Sun and is beginning the journey out into the solar system. The white circle in (c) and (d) shows the diameter of the solar photosphere. The larger dark area shows where light from the Sun has been blocked out by a specially designed instrument to make it possible to see the faint emission from the corona. (credit a, b, c, d: modification of work by SOHO/EIT, SOHO/LASCO, SOHO/MDI (ESA & NASA))arrow_forward
- Show that the statement that 92% of the Sun’s atoms are hydrogen is consistent with the statement that 73% of the Sun’s mass is made up of hydrogen, as found in Table 15.2. (Hint: Make the simplifying assumption, which is nearly correct, that the Sun is made up entirely of hydrogen and helium.)arrow_forwardAssuming an average sunspot cycle of 11 years, how many revolutions does the equator of the Sun make during that one cycle? Do higher latitudes make more or fewer revolutions compared to the equator?arrow_forwardNeutrinos produced in the core of the Sun carry energy to its exterior. Is the mechanism for this energy transport conduction, convection, or radiation?arrow_forward
- How would the interior temperature of the Sun be different if the strong force that binds nuclei together were 10 times as strong?arrow_forwardA Crude Analysis: In about 5 billion years, the Sun is going to look a lot different. Our sun is going to turn into a red-giant, a bigger star whose core temperature is much higher than the Sun's current core temperature (you will learn about the red giants in the coming weeks). Assume the core temperature of the red-giant phase of the Sun does not go beyond 100 million degrees. Do you think the temperature is high enough for helium fusion to occur? Note that this question is about helium fusion not hydrogen fusion. How are you going about proving your claim? Question: What temperature in degrees Kelvin must the red-giant sun be at to allow for the helium-helium interactions to take place not considering the Quantum Mechanical effects (i.e. what temperature would allow helium atoms to breach the helium-helium potential wall without help from Quantum Mechanics)? Use wolfram alpha to find the values for the constants. Round your answer to two decimal places. Your answer i [ Select ] 1.47…arrow_forwardThe average density of the sun is 1. 4 g/cm3 What do you expect the density to be at 0.25 of Rsun? 2) The average density of the sun is 1.4 g/cm3. The following resource claims that the sun's core has a density of 150 g/cm3 and a radius of 25% of the sun's radius. Assume the core has a constant density and calculate it's mass. What fraction of the sun's mass is in the core according to that resource?arrow_forward
- Status of Sun's core and its temperature (The letters correspond to the stages in Figure 21.1.) 3. Stage A: T10 million K. Sun is in equilibrium. 4. Stage B: T 100 million K Core collapse stops. 5. Stage C: Helium flash 6. Stage D: T 100 million K. Sun is in equilibrium. 7. Stage E: T800 million K. Core collapse stops. If fusion is occurring in core or in shell around the core, mark with a ✔in the correct column. Core fusion H to He FUSION ✓ Core fusion He to C Shell fusion H to He Shell fusion He to C PRESSURE VERSUS GRAVITY CORE • REST OF THE STAR Pressure comes from electron degeneracy Pressure Gravity Gravity Pressure region contracts and heats Pressure > Gravity region expands and coolsarrow_forwardExplain in detail the carbon-nitrogen-oxygen fusion chain that occurs in the center of the Sunarrow_forwardWhy the sun does not get ripped apart by the outwards pressure of nuclear fusion?arrow_forward
- AstronomyPhysicsISBN:9781938168284Author:Andrew Fraknoi; David Morrison; Sidney C. WolffPublisher:OpenStaxStars and Galaxies (MindTap Course List)PhysicsISBN:9781337399944Author:Michael A. SeedsPublisher:Cengage LearningFoundations of Astronomy (MindTap Course List)PhysicsISBN:9781337399920Author:Michael A. Seeds, Dana BackmanPublisher:Cengage Learning
- An Introduction to Physical SciencePhysicsISBN:9781305079137Author:James Shipman, Jerry D. Wilson, Charles A. Higgins, Omar TorresPublisher:Cengage Learning