Concept explainers
The reason why the interior of an evolved high-mass stars has layers like those of an onion.
Answer to Problem 1QP
Options (c).
Explanation of Solution
High-mass stars are stars with masses greater than about eight times mass of the Sun. As a high-mass star evolves, it builds up a layered structure like that of an onion, with progressively more advanced stages of nuclear fusion found deeper and deeper within the star.
As the high-mass star leaves the main sequence, the core will begin to collapse and the carbon fusion will occur. Carbon fusion will produce more massive elements including oxygen, sodium, neon and magnesium. The star then will have a carbon fusing core surrounded by a helium-fusing shell surrounded by a hydrogen-fusing shell, which moves outward as fusion products accumulate in the core. When carbon is exhausted as a nuclear fuel at the center of the star, neon breaks down to oxygen and helium or fuses to magnesium; and when neon is exhausted, oxygen begins to fuse. Thus, the residue of one reaction becomes the fuel for the next as the star evolves a layered structure like that of onion.
Conclusion:
Since a high-mass star develops a layered structure as a result of the heavier atoms fuse closer to the center because the high pressure and temperature available there, option (c) is correct.
Want to see more full solutions like this?
Chapter 17 Solutions
21ST CENTURY ASTR.:SOLAR..(LL)-PACKAGE
- Which of the following statements about various stages of core nuclear burning (hydrogen, helium, carbon, etc.) in a high- mass star is not true? A. As each stage ends, the core shrinks and heats further. B. Each successive stage creates an element with a higher atomic number and atomic mass number. C. As each stage ends, the reactions that occurred in previous stages continue in shells around the core. D.Each successive stage lasts for approximately the same amount of time.arrow_forwardThe theory that the collapse of a massive star’s iron core produces neutrinos was supported by a. the size and structure of the Crab nebula. b. laboratory measurements of the mass of the neutrino. c. the brightening of supernovae a few days after they are first visible. d. underground counts from solar neutrinos. e. the detection of neutrinos from the supernova of 1987.arrow_forwardWhich of the following binary star systems cannot exist? A. A 1 solar-mass main sequence star and a 4 solar mass red giant with a size 100 times smaller than the orbital distance. B. A 15 solar-mass main sequence star and a 10 solar mass red giant with a size 100 times smaller than the orbital distance. C. A 1 solar-mass main sequence star and a 4 solar-mass main sequence star. D. A 2 solar-mass main sequence star and a 1 solar mass red giant with a size a few times smaller than the orbital distance.arrow_forward
- There is a mass–luminosity relation because a. hydrogen fusion produces helium. b. stars expand when they become giants. c. stars support their weight by making energy. d. the helium flash occurs in degenerate matter. e. all stars on the main sequence have about the same radius.arrow_forward4. Suppose we observe a binary star system in which one star is much more massive than the other and both are on the main sequence. We measure that the smaller star orbits the larger at a distance of 10¹3 m with a speed of 10 m/s. a. What is the mass of the larger star? b. Which star has a higher luminosity? c. Which has a larger radius? d. Which is hotter?arrow_forwardAbsorption lines produced by interstellar gas a. are wider than the lines from stars because the gas is hotter than most stars. b. are more narrow than the lines from stars because the gas has a lower pressure than stars. c. indicate that the interstellar medium contains dust. d. indicate that the interstellar medium is expanding away from the sun. e. indicate nothing; none of the above statements are true.arrow_forward
- Based on what you learned about stellar structure and how stars maintain their stability, select all of the correct statements from the following list. 1. The weight pressing down on a layer of gas in a star is balanced by the pressure in the gas. 2. The interior of the lowest-mass stars transfers energy mostly through convection. 3. Energy in a star flows from the core to the surface. 4. More massive stars produce energy with the proton-proton cycle. 5. Less massive stars produce energy with the CNO cycle. 6. Conduction is an important method of energy transport in stars. 7. Stars are hotter in their cores than on their surfaces.arrow_forwardYou discover a binary star system in which one member is a 15 solar-mass main-sequence star and the other star is a 10 solar-mass giant. Why should you be surprised, at least at first? A. It doesn't make sense to find a giant in a binary star system. B. The two stars in a binary system should both be at the same point in stellar evolution; that is, they should either both be main-sequence stars or both be giants. C. The two stars should be the same age, so the more massive one should have become a giant first. D. The odds of ever finding two such massive stars in the same binary system are so small as to make it inconceivable that such a system could be discovered. E. A star with a mass of 15 solar-mass is too big to be a main-sequence star.arrow_forwardAs a white dwarf cools, its radius will not change because a. pressure resulting from nuclear reactions in a shell just below the surface keeps it from collapsing. b. pressure does not depend on temperature for a white dwarf because the electrons are degenerate. c. pressure does not depend on temperature because the white dwarf is too hot. d. pressure does not depend on temperature because the star has exhausted all its nuclear fuels. e. material accreting onto it from a companion maintains a constant radius.arrow_forward
- A group of graduate students, bored during a cloudy night at a the observatory, begin to make bets about the time different stars will take to evolve. If they have a cluster of stars which were all born roughly the same time, and want to know which star will become a red giant first, which of the following stars should they bet on? a. a star that would type O on the main sequence star b. a star about 1/2 the mass of our sun c. a star about 8% the mass of our sun d. all stars reach the red giant stage in roughly the same number of yearsarrow_forwardThe gas and dust cocoon surrounding young stars a. is blown away when the young stellar surface heats up and becomes more luminous. b. remains surrounding the young star throughout its adult life. c. eventually collapses onto the star, increasing its mass and luminosity. d. evaporates gradually over the lifetime of the star. e. expands as the star’s luminosity increases eventually reaching a distance far enough that it condenses to form comets.arrow_forwardWhich of the following is wrong? A. Tidal effects in a binary star system become more important when one or both stars become giant stars. B. There is no fusion occurring in the core of a low-mass red giant star. C. Gold (the element) is produced during the supernova explosions of high-mass stars. D. Suppose the star Betelgeuse were to become a supernova tomorrow, we'd see by naked eyes a cloud of gas expanding away from the position where Betelgeuse used to be. Over a period of a few weeks, this cloud would fill a large part of our sky.arrow_forward
- Foundations of Astronomy (MindTap Course List)PhysicsISBN:9781337399920Author:Michael A. Seeds, Dana BackmanPublisher:Cengage Learning