Concept explainers
The reason behind a red dwarf not leaving the main sequence.
Answer to Problem 1CC
Solution:
To leave the main sequence, a red dwarf should finish converting its core hydrogen to helium, which also determines its lifetime, but it takes millions of years, which is more than the life of the universe.
Explanation of Solution
Introduction:
A red dwarf star belongs to the main sequence stars of M type. It is a small and cool star, its red color is due to cool temperature. A red dwarf has
Explanation:
Due to the thermonuclear reactions occurring in the core, helium is produced and this gets replaced by the hydrogen from the outer layers of the star. Convection cells of the rising and falling gases lead to the replacement of the helium produced in the core. This ultimately fuels the star and increases its lifetime. According to the calculations, this lifetime can be hundreds of billions of years, but the present age of the universe is 13.6 billion years only. Hence, a red dwarf cannot leave the main sequence.
Conclusion:
Due to its huge lifetime, a red dwarf is unable to leave the main sequence.
Want to see more full solutions like this?
Chapter 19 Solutions
Universe
- Why do you think astronomers have suggested three different spectral types (L, T, and Y) for the brown dwarfs instead of M? Why was one not enough?arrow_forwardWould you expect to find any white dwarfs in the Orion Nebula? (See The Birth of Stars and the Discovery of Planets outside the Solar System to remind yourself of its characteristics.) Why or why not?arrow_forwardSuppose you want to search for brown dwarfs using a space telescope. Will you design your telescope to detect light in the ultraviolet or the infrared part of the spectrum? Why?arrow_forward
- Arrange the following stars in order of their evolution: A. A star with no nuclear reactions going on in the core, which is made primarily of carbon and oxygen. B. A star of uniform composition from center to surface; it contains hydrogen but has no nuclear reactions going on in the core. C. A star that is fusing hydrogen to form helium in its core. D. A star that is fusing helium to carbon in the core and hydrogen to helium in a shell around the core. E. A star that has no nuclear reactions going on in the core but is fusing hydrogen to form helium in a shell around the core.arrow_forwardHow do the two types of supernovae discussed in this chapter differ? What kind of star gives rise to each type?arrow_forwardAccording to the text, a star must be hotter than about 25,000 K to produce an H II region. Both the hottest white dwarfs and main-sequence O stars have temperatures hotter than 25,000 K. Which type of star can ionize more hydrogen? Why?arrow_forward
- Stars 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 LearningStars and GalaxiesPhysicsISBN:9781305120785Author:Michael A. Seeds, Dana BackmanPublisher:Cengage Learning
- AstronomyPhysicsISBN:9781938168284Author:Andrew Fraknoi; David Morrison; Sidney C. WolffPublisher:OpenStax