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 5, Problem 23Q
To determine
The luminosity of sun.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
1 Solar constant, Sun, and the 10 pc distance!
The luminosity of Sun is + 4- 1026 W - 4- 1033ergs-1, The Sun is located at a distance of
m from the Earth. The Earth receives a radiant flux (above its atmosphere) of F = 1365W m- 2, also known as
the solar constant. What would have been the Solar contact if the Sun was at a distance of 10 pc ?
1AU 1 1.5-+ 1011
As a star runs out of hydrogen to fuel nuclear fusion in its core, changes within the star usually cause it to leave the main sequence, expanding and cooling as it does so. Would a star with a radius 12 times that of the Sun, but a surface temperature 0.5 times that of the Sun, be more, or less luminous than the Sun?
Show and explain your reasoning.
You may assume the surface area of a sphere is A = 4πr2.
The origin of the above quote (with "flame" or "candle" sometimes substituted for "light") is unclear. It is often attributed to either Lao Tzu or to the character Eldon Tyrell from the 1982 movie Blade Runner.
Stars follow a similar law, although the factor isn't precisely 1/2. In this problem, you will figure out the precise factor that the quote should have to apply to stars.
Using the proportionality relationships for stellar luminosity as a function of mass and stellar lifetime as a function of mass, combine the two equations to arrive at a proportionality for stellar lifetime as a function of luminosity.
Consider a star with luminosity twice that of the Sun's. Compute the star's main sequence lifetime as a multiple of the Sun's main sequence lifetime. Enter your result below as a decimal. For example, if you found TT⊙=0.3, enter "0.3". (Here T is the star's lifetime and T⊙ is the Sun's main sequence lifetime.
Chapter 5 Solutions
Universe: Stars And Galaxies
Ch. 5 - Prob. 1QCh. 5 - Prob. 2QCh. 5 - Prob. 3QCh. 5 - Prob. 4QCh. 5 - Prob. 5QCh. 5 - Prob. 6QCh. 5 - Prob. 7QCh. 5 - Prob. 8QCh. 5 - Prob. 9QCh. 5 - Prob. 10Q
Ch. 5 - Prob. 11QCh. 5 - Prob. 12QCh. 5 - Prob. 13QCh. 5 - Prob. 14QCh. 5 - Prob. 15QCh. 5 - Prob. 16QCh. 5 - Prob. 17QCh. 5 - Prob. 18QCh. 5 - Prob. 19QCh. 5 - Prob. 20QCh. 5 - Prob. 21QCh. 5 - Prob. 22QCh. 5 - Prob. 23QCh. 5 - Prob. 24QCh. 5 - Prob. 25QCh. 5 - Prob. 26QCh. 5 - Prob. 27QCh. 5 - Prob. 28QCh. 5 - Prob. 29QCh. 5 - Prob. 30QCh. 5 - Prob. 31QCh. 5 - Prob. 32QCh. 5 - Prob. 33QCh. 5 - Prob. 34QCh. 5 - Prob. 35QCh. 5 - Prob. 36QCh. 5 - Prob. 37QCh. 5 - Prob. 38QCh. 5 - Prob. 39QCh. 5 - Prob. 40QCh. 5 - Prob. 41QCh. 5 - Prob. 42QCh. 5 - Prob. 43QCh. 5 - Prob. 44QCh. 5 - Prob. 45QCh. 5 - Prob. 46QCh. 5 - Prob. 47QCh. 5 - Prob. 48QCh. 5 - Prob. 49QCh. 5 - Prob. 50QCh. 5 - Prob. 51Q
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
- How does the temperature of the peak (maximum) wavelength of 41 Cygni (at baseline level) compare with the sun? Why is there a difference?arrow_forwardHow does this radius of Sirius B compare with that of Earth?arrow_forwardFrom Doppler shifts of the spectral lines in the light coming from the east and west edges of the Sun, astronomers find that the radial velocities of the two edges differ by about 4 km/s, meaning that the Sun’s rotation rate is 2 km/s. Find the approximate period of rotation of the Sun in days. The circumference of a sphere is given by 2pR, where R is the radius of the sphere.arrow_forward
- From 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_forwardConfirm that the angular diameter of the Sun of 1/2° corresponds to a linear diameter of 1.39 million km. Use the average distance of the Sun and Earth to derive the answer. (Hint: This can be solved using a trigonometric function.)arrow_forwardYou have enough information from this chapter to estimate the distance to Alpha Centauri, the second nearest star, which has an apparent magnitude of 0. Since it is a G2 star, like the Sun, assume it has the same luminosity as the Sun and the difference in magnitudes is a result only of the difference in distance. Estimate how far away Alpha Centauri is. Describe the necessary steps in words and then do the calculation. (As we will learn in the Celestial Distances chapter, this method-namely, assuming that stars with identical spectral types emit the same amount of energy-is actually used to estimate distances to stars.) If you assume the distance to the Sun is in AU, your answer will come out in AU.arrow_forward
- A G2 star has a luminosity 100 times that of the Sun. What kind of star is it? How does its radius compare with that of the Sun?arrow_forwardThe star Sirius A has an apparent magnitude of 1.5 . Sirius A has a dim companion, Sirius B, which is 10,000 times less bright than Sirius A. What is the apparent magnitude of Sirius B? Can Sirius B be seen with the naked eye?arrow_forwardSpectral types are an indicator of temperature. For the first 10 stars in Appendix J, the list of the brightest stars in our skies, estimate their temperatures from their spectral types. Use information in the figures and/or tables in this chapter and describe how you made the estimates.arrow_forward
arrow_back_ios
arrow_forward_ios
Recommended textbooks for you
Stars and Galaxies (MindTap Course List)PhysicsISBN:9781337399944Author:Michael A. SeedsPublisher:Cengage Learning
Foundations of Astronomy (MindTap Course List)PhysicsISBN:9781337399920Author:Michael A. Seeds, Dana BackmanPublisher:Cengage Learning
AstronomyPhysicsISBN:9781938168284Author:Andrew Fraknoi; David Morrison; Sidney C. WolffPublisher:OpenStax
Stars and Galaxies (MindTap Course List)
Physics
ISBN:9781337399944
Author:Michael A. Seeds
Publisher:Cengage Learning
Foundations of Astronomy (MindTap Course List)
Physics
ISBN:9781337399920
Author:Michael A. Seeds, Dana Backman
Publisher:Cengage Learning
Astronomy
Physics
ISBN:9781938168284
Author:Andrew Fraknoi; David Morrison; Sidney C. Wolff
Publisher:OpenStax