Universe: Stars And Galaxies
6th Edition
ISBN: 9781319115098
Author: Roger Freedman, Robert Geller, William J. Kaufmann
Publisher: W. H. Freeman
expand_more
expand_more
format_list_bulleted
Concept explainers
Question
Chapter 20, Problem 26Q
To determine
The reason for different kinds of dwarfs to not collapse under their own gravity in terms of different types of pressure.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
What is the luminosity, in solar units, of a brown dwarf whose radius is 0.1 solar radii and whose surface temperature is 600 K (0.1
times that of the Sun)?
We learned in class that, when stars collapse under their own gravity, they conserve angular momentum, which is proportional to
mass times radius times rotational speed. Suppose the entire sun (radius 695,700 km) were to collapse to a neutron star with a
radius of only 10 km. Before the collapse, the rotational speed at the equator = 2.0 km/s, and the rotational period is 25 days.
Using the same steps that you used for the white dwarf calculations, calculate the final rotation period if the entire sun were to
collapse to a 10 km radius neutron star. Give your answer in units of seconds.
Answer:
Check
One way to calculate the radius of a star is to use its luminosity and temperature and assume that the star radiates approximately like a blackbody. Astronomers have measured the characteristics of central stars of planetary nebulae and have found that a typical central star is 16 times as luminous and 20 times as hot (about 110,000 K) as the Sun. Find the radius in terms of the Sun’s. How does this radius compare with that of a typical white dwarf?
Chapter 20 Solutions
Universe: Stars And Galaxies
Ch. 20 - Prob. 1QCh. 20 - Prob. 2QCh. 20 - Prob. 3QCh. 20 - Prob. 4QCh. 20 - Prob. 5QCh. 20 - Prob. 6QCh. 20 - Prob. 7QCh. 20 - Prob. 8QCh. 20 - Prob. 9QCh. 20 - Prob. 10Q
Ch. 20 - Prob. 11QCh. 20 - Prob. 12QCh. 20 - Prob. 13QCh. 20 - Prob. 14QCh. 20 - Prob. 15QCh. 20 - Prob. 16QCh. 20 - Prob. 17QCh. 20 - Prob. 18QCh. 20 - Prob. 19QCh. 20 - Prob. 20QCh. 20 - Prob. 21QCh. 20 - Prob. 22QCh. 20 - Prob. 23QCh. 20 - Prob. 24QCh. 20 - Prob. 25QCh. 20 - Prob. 26QCh. 20 - Prob. 27QCh. 20 - Prob. 28QCh. 20 - Prob. 29QCh. 20 - Prob. 30QCh. 20 - Prob. 31QCh. 20 - Prob. 32QCh. 20 - Prob. 33QCh. 20 - Prob. 34QCh. 20 - Prob. 35QCh. 20 - Prob. 36QCh. 20 - Prob. 37QCh. 20 - Prob. 38QCh. 20 - Prob. 39QCh. 20 - Prob. 40QCh. 20 - Prob. 41QCh. 20 - Prob. 42QCh. 20 - Prob. 43QCh. 20 - Prob. 44QCh. 20 - Prob. 45QCh. 20 - Prob. 46QCh. 20 - Prob. 47QCh. 20 - Prob. 48QCh. 20 - Prob. 49QCh. 20 - Prob. 50QCh. 20 - Prob. 51QCh. 20 - Prob. 52QCh. 20 - Prob. 53QCh. 20 - Prob. 54QCh. 20 - Prob. 55QCh. 20 - Prob. 56QCh. 20 - Prob. 57QCh. 20 - Prob. 58QCh. 20 - Prob. 59QCh. 20 - Prob. 60QCh. 20 - Prob. 61QCh. 20 - Prob. 62QCh. 20 - Prob. 63QCh. 20 - Prob. 64QCh. 20 - Prob. 65QCh. 20 - Prob. 66QCh. 20 - Prob. 67QCh. 20 - Prob. 68QCh. 20 - Prob. 69QCh. 20 - Prob. 70QCh. 20 - Prob. 71QCh. 20 - Prob. 72QCh. 20 - Prob. 73QCh. 20 - Prob. 74QCh. 20 - Prob. 75Q
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, physics and related others by exploring similar questions and additional content below.Similar questions
- What physical properties are different for an M giant with a luminosity of 1000 LSunand an M dwarf with a luminosity of 0.5 LSun? What physical properties are the same?arrow_forwardHow much would you weigh if you were suddenly transported to the white dwarf Sirius B? You may use your own weight (or if don’t want to own up to what it is, assume you weigh 70 kg or 150 lb). In this case, assume that the companion to Sirius has a mass equal to that of the Sun and a radius equal to that of Earth. Remember Newton’s law of gravity: F=GM1M2/R2 and that your weight is proportional to the force that you feel. What kind of star should you travel to if you want to lose weight (and not gain it)?arrow_forwardA star begins its life with a mass of 5 MSunbut ends its life as a white dwarf with a mass of 0.8 MSun. List the stages in the star’s life during which it most likely lost some of the mass it started with. How did mass loss occur in each stage?arrow_forward
- Why are Cepheid variables important? O Cepheids variables are pulsating stars whose pulsation periods are directly related to their true luminosities. Therefore they can be used as distance indicators. O Cepheids variables are supermassive stars that are on the verge of becoming supernovae. Therefore they allow us to choose candidates to watch if we hope to observe a supernova. O Cepheid variables are stars that vary in brightness because they harbor a black hole. Therefore, they provide direct evidence for black holes. O Cepheids variables are a type of irregular galaxy, much more common in the early universe. Therefore they help to understand how galaxies formed.arrow_forwardWhite dwarfs have a temperature of 100×103 K. Calculate the maximum wavelength of a White dwarf.arrow_forwardAn M dwarf star of mass 0.1 solar masses, a radius of 0.13 solar radii and a photospheric temperature of 2708 Kelvin. Assuming the dwarf contains the same mixture of elements as the Sun, and that the thermal pressure of the Sun's core is 1.3 x 10^14 N/m^2 estimate the ratio between the thermal pressure in the M dwarf's core versus that of the Sun. select unitsarrow_forward
- As 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_forwardWhat happens to a white dwarf when a normal star dumps mass to a white dwarf? Group of answer choices The white dwarf get smaller, causing its temperature and density to decrease. The white dwarf get smaller, causing its temperature and density to increase. The white dwarf get larger, causing its temperature and density to decrease. The white dwarf get larger, causing its temperature and density to increase.arrow_forwardWhy are red dwarfs very dim.arrow_forward
arrow_back_ios
arrow_forward_ios
Recommended textbooks for you
AstronomyPhysicsISBN:9781938168284Author:Andrew Fraknoi; David Morrison; Sidney C. WolffPublisher:OpenStax
Foundations of Astronomy (MindTap Course List)PhysicsISBN:9781337399920Author:Michael A. Seeds, Dana BackmanPublisher:Cengage Learning
Horizons: Exploring the Universe (MindTap Course ...PhysicsISBN:9781305960961Author:Michael A. Seeds, Dana BackmanPublisher:Cengage Learning
Stars and Galaxies (MindTap Course List)PhysicsISBN:9781337399944Author:Michael A. SeedsPublisher:Cengage Learning
Stars and GalaxiesPhysicsISBN:9781305120785Author:Michael A. Seeds, Dana BackmanPublisher:Cengage Learning
Astronomy
Physics
ISBN:9781938168284
Author:Andrew Fraknoi; David Morrison; Sidney C. Wolff
Publisher:OpenStax
Foundations of Astronomy (MindTap Course List)
Physics
ISBN:9781337399920
Author:Michael A. Seeds, Dana Backman
Publisher:Cengage Learning
Horizons: Exploring the Universe (MindTap Course ...
Physics
ISBN:9781305960961
Author:Michael A. Seeds, Dana Backman
Publisher:Cengage Learning
Stars and Galaxies (MindTap Course List)
Physics
ISBN:9781337399944
Author:Michael A. Seeds
Publisher:Cengage Learning
Stars and Galaxies
Physics
ISBN:9781305120785
Author:Michael A. Seeds, Dana Backman
Publisher:Cengage Learning