Concept explainers
(a)
The escape velocity when the Sun becomes a red giant.
(a)
Answer to Problem 40QAP
The escape velocity when the Sun becomes a red giant is
Explanation of Solution
Write the expression for escape velocity.
Here,
Compare the velocities for different masses and radius of the Sun and simplify.
Here, subscript 1 is used for mass, radius and velocity of initial phase and subscript 2 is used for mass, radius and velocity of final phase.
Rearrange the above expression in term of
Conclusion:
Substitute
Thus, the escape velocity when the Sun becomes a red giant is
(b)
The escape velocity when the Sun becomes AGB star.
(b)
Answer to Problem 40QAP
The escape velocity when the Sun becomes AGB star is
Explanation of Solution
Conclusion:
Substitute
Thus, the escape velocity when the Sun becomes a red giant is
(c)
The effect on mass loss with the changes in escape velocity.
(c)
Answer to Problem 40QAP
Mass loss increases with the decrease in escape velocity and vice versa.
Explanation of Solution
The star loses it mass when it leaves the main-sequence phase. The mass loss depends on the nuclear burning and gravity of the star. The escape velocity is the velocity of an object with which the object can escape the atmosphere of the star.
The escape velocity depends upon the mass and radius of the Sun; it is directly proportional to the mass of Sun and inversely proportional to the radius of Sun. During evolution of star, its mass reduces and radius increases for red giant and AGB star.
The escape velocity reduces with the increase in size and decrease in mass; hence object can easily escape the surface of star. Therefore, mass loss from the surface of the Sun increases.
Conclusion:
Thus, the mass loss increases with the decrease in escape velocity and vice versa.
Want to see more full solutions like this?
Chapter 12 Solutions
Understanding Our Universe
- A (relatively) nearby K-type star known as Nu? Canis Majoris has an estimated orbital radius of 2.3344 x 10° km, and an estimated orbital period of 736.9 days. a. What is the mass of Nu? Canis Majoris? b. What is the mass of Nu² Canis Majoris in terms of solar masses?arrow_forwardObservations show that stellar luminosity, L, and mass, M, are related by L x M3.5 for main sequence stars. Obtain an expression that relates the main sequence life time and the mass of a star. You should assume that the luminosity is constant throughout a star's main sequence life time, and that the amount of mass converted into energy by a star while it is on the main sequence is given by AM main sequence life time of a 20 Solar mass star given that the Sun is expected to spend 1010 years on the main sequence. Comment on the significance of your answer. fM, where f is a constant. Estimate thearrow_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
- Assume that when a certain main sequence star becomes a giant gas, its luminosity increases from L to 1000 L and its radius also increases from R to 1000 R. If the initial surface temperature is T, what approximately is the final surface temperature? A. 0.032 T B. 0.18 T C. 0.0010 T D. 0.010 Tarrow_forwardA 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 Hertzsprung-Russell diagram contains a region called the main sequence. Stars on this sequence have specific characteristics not found in other stars. What are these characteristics? a.Stars on the Hertzsprung-Russell diagram main sequence have roughly the same age. b.Stars on the main sequence of the Hertzsprung-Russell diagram are all roughly the same radius. c.Stars on the main sequence of the Hertzsprung-Russell diagram have an orderly arrangement of stellar masses, decreasing in mass from lower right to upper left. d.Stars on the main sequence of a Hertzsprung-Russell diagram do not produce heavy elements like iron. e.Stars on the main sequence of a Hertzsprung-Russell diagram all generate energy from nuclear fusion. f.None of the mentioned choices. Aristotle was a great Greek philosopher with many amazing ideas. Which of these statements about him is not true? a.Many of his claims about physics and astronomy were wrong. b.He was the first person to recognize…arrow_forward
- Which 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_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_forwardWhat kind of star is most likely to become a white-dwarf supernova? A. a star like our Sun B. a white dwarf star with a red giant binary companion C. a pulsar D. an O star Is the answer B? For D, as the surface temperature of a star would change over time so spectral type cannot tell us about the fate of the stars?arrow_forward
- 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?arrow_forwardWhich of the following statements is wrong? A. A main-sequence star is cooler and brighter than it was as a protostar. B. Carbon fusion occurs in high-mass stars but not in low-mass stars because the cores of low-mass stars never contain significant amounts of carbon. C. when a main-sequence star exhausts its core hydrogen fuel supply, the core shrinks while the rest of the star expands. D. After a supernova explosion, the remains of the stellar core will be either a neutron star or a black hole.arrow_forwardBetelgeuse is a nearby supergiant that will eventually explode into a supernova. At peak brightness, the supernova will have a luminosity of about 20 billion times the Sun. It is 600 lightyears away. All stellar brightnesses are compared with Vega, which has an intrinsic luminosity of about 60 times the sun, a distance of 25 lightyears away, an absolutely magnitude of 0.6 and an apparent magnitude of 0. a) At peak brightness, how many times brighter will betelgeuses be than Vega? b) Approximately what apparent magnitude does this correspond to? c) The sun is about -26.5 apparent magnitude. What fraction of the Sun'ss brightness will Betelgeuse be?arrow_forward
- University Physics Volume 3PhysicsISBN:9781938168185Author:William Moebs, Jeff SannyPublisher:OpenStaxFoundations of Astronomy (MindTap Course List)PhysicsISBN:9781337399920Author:Michael A. Seeds, Dana BackmanPublisher:Cengage LearningStars and Galaxies (MindTap Course List)PhysicsISBN:9781337399944Author:Michael A. SeedsPublisher:Cengage Learning
- AstronomyPhysicsISBN:9781938168284Author:Andrew Fraknoi; David Morrison; Sidney C. WolffPublisher:OpenStaxStars and GalaxiesPhysicsISBN:9781305120785Author:Michael A. Seeds, Dana BackmanPublisher:Cengage Learning