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 17, Problem 41Q
To determine
(a)
The most prominent absorption lines found in the spectrum of a star having a surface temperature of
To determine
(b)
The most prominent absorption lines found in the spectrum of a star having a surface temperature of
To determine
(c)
The most prominent absorption lines found in the spectrum of a star having a surface temperature of
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solutionStudents have asked these similar questions
12.
A star with spectral type MO has a surface temperature of 3750 K and a radius of 0.63 Rsun: How many
times more luminous is this star than the Sun? (if it is less luminous enter a number less than one)
Answer:
Submit All Answers Last Answer: 0.0923
Incorrect, tries 1/5.
Hint: Use the Luminosity equation, which says that L is proportional to R^2 T^4. If you keep these as
ratios compared to the sun, your L will also come out as a ratio compared to the Sun.
This star has a mass of 0.4 Msun- Using the simple approximation that we made in class, what is the
main sequence lifetime of this star? You may assume that the lifetime of the sun is 1010 yr.
Answer:
Submit All Answers
Compare this to the lifetime of a MO star listed in Table 22.1 (computed using a more sophisticated
approach). Is the value you calculated in the previous problem longer or shorter than what is reported
in the table? (L for longer, S for shorter) (You only get one try at this problem.)
Answer:
Submit All Answers
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 6 times that of the Sun, but a surface temperature 0.4 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.
A star has a surface temperature of T = 10,000 K and a radius three times that of the Sun, R = 3R (recall that symbolizes the Sun). What is its luminosity, L, in units of solar luminosities, L? Give your answer to three significant figures.
answer, expressed in solar luminosities, tells how many times more luminous this star is than the Sun.
Chapter 17 Solutions
Universe: Stars And Galaxies
Ch. 17 - Prob. 1QCh. 17 - Prob. 2QCh. 17 - Prob. 3QCh. 17 - Prob. 4QCh. 17 - Prob. 5QCh. 17 - Prob. 6QCh. 17 - Prob. 7QCh. 17 - Prob. 8QCh. 17 - Prob. 9QCh. 17 - Prob. 10Q
Ch. 17 - Prob. 11QCh. 17 - Prob. 12QCh. 17 - Prob. 13QCh. 17 - Prob. 14QCh. 17 - Prob. 15QCh. 17 - Prob. 16QCh. 17 - Prob. 17QCh. 17 - Prob. 18QCh. 17 - Prob. 19QCh. 17 - Prob. 20QCh. 17 - Prob. 21QCh. 17 - Prob. 22QCh. 17 - Prob. 23QCh. 17 - Prob. 24QCh. 17 - Prob. 25QCh. 17 - Prob. 26QCh. 17 - Prob. 27QCh. 17 - Prob. 28QCh. 17 - Prob. 29QCh. 17 - Prob. 30QCh. 17 - Prob. 31QCh. 17 - Prob. 32QCh. 17 - Prob. 33QCh. 17 - Prob. 34QCh. 17 - Prob. 35QCh. 17 - Prob. 36QCh. 17 - Prob. 37QCh. 17 - Prob. 38QCh. 17 - Prob. 39QCh. 17 - Prob. 40QCh. 17 - Prob. 41QCh. 17 - Prob. 42QCh. 17 - Prob. 43QCh. 17 - Prob. 44QCh. 17 - Prob. 45QCh. 17 - Prob. 46QCh. 17 - Prob. 47QCh. 17 - Prob. 48QCh. 17 - Prob. 49QCh. 17 - Prob. 50QCh. 17 - Prob. 51QCh. 17 - Prob. 52QCh. 17 - Prob. 53QCh. 17 - Prob. 54QCh. 17 - Prob. 55QCh. 17 - Prob. 56QCh. 17 - Prob. 57QCh. 17 - Prob. 58QCh. 17 - Prob. 59QCh. 17 - Prob. 60QCh. 17 - Prob. 61QCh. 17 - Prob. 62QCh. 17 - Prob. 63QCh. 17 - Prob. 64QCh. 17 - Prob. 65QCh. 17 - Prob. 66QCh. 17 - Prob. 67QCh. 17 - Prob. 68QCh. 17 - Prob. 69QCh. 17 - Prob. 70QCh. 17 - Prob. 71QCh. 17 - Prob. 72QCh. 17 - Prob. 73QCh. 17 - Prob. 74QCh. 17 - Prob. 75QCh. 17 - Prob. 76QCh. 17 - Prob. 77QCh. 17 - Prob. 78QCh. 17 - Prob. 79QCh. 17 - Prob. 80Q
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
- Choose the statements that correctly describe the characteristics of the stars located in the labeled quadrants of the H-R diagram. Luminosityarrow_forwardThe spectrum of a typical star shows absorption lines at different wavelengths than their laboratory values. If the observed wavelength is greater than its laboratory value of 656.3 nm, one can conclude that ... A. The separation between Earth and the star is decreasing. B. The separation between Earth and the star is increasing. O C. The separation between Earth and the star is unchanging D. No conclusion is possible.arrow_forward"51 Pegasi" is the name of the first normal star (besides the Sun) around which a planet was discovered. It is in the constellation Pegasus the horse. Its parallax is measured to be 0.064 arcsec. a. What is its distance from us? b. The apparent brightness is 1.79 × 10-10 J/(s·m2 ). What is the luminosity? How does that compare with that of the Sun? Look up the temperature: how doarrow_forwardA star with a radius 1.7 times that of the Sun has a surface temperature T=10,000 K. Calculate the luminosity of this star and express your answer in units of the Solar luminosity (the Solar luminosity = 3.84 x 1026 W and the Solar radius = 7 x %3D 108 m). Choose the option below that most closely matches your answer. Select one: а. 20 O b. 100. O C. 26. O d. 5. O e. 1000arrow_forwardChoose the correct statements concerning spectral classes of stars. (Give ALL correct answers, i.e., B, AC, BCD...) A) K-stars are dominated by lines from ionized helium because they are so hot. B) Oh Be A Fine Guy/Girl Kiss Me, is a mnemonic for remembering spectral classes. C) The spectral sequence has recently been expanded to include L, T, and Y classes. D) Hydrogen lines are weak in type O-stars because most of it is completely ionized. E) Neutral hydrogen lines dominate the spectrum for stars with temperatures around 10,000 K because a lot of the hydrogen is in the n=2 level. F) The spectral types of stars arise primarily as a result of differences in chemical composition.arrow_forward. The spectrum of Star A peaks at 700 nm. The spectrum of Star B peaks at 470 nm. We know nothing about what stage of stellar evolution either of these stars are in. Which of the following are true? A. Star A has a higher luminosity than Star B. B. Star B has a higher luminosity than Star A. C. Star A is cooler than Star B. D. Not enough information to comment on their luminosities. E. B and C F. C and Darrow_forwardThe spectrum of a typical star shows absorption lines at different wavelengths than their laboratory values. If the observed wavelength is less than its laboratory value of 656.3 nm, one can conclude that... A. The separation between Earth and the star is decreasing. B. The separation between Earth and the star is increasing. C. The separation between Earth and the star is unchanging D. No conclusion is possible.arrow_forwardAstronomers use two basis properties of stars to classify them. These two properties are luminosity and surface temperature. Luminosity usually refers to the brightness of the star relative to the brightness of our sun. Astronomers will often use a star’s color to measure its temperature. Stars with low temperatures produce a reddish light while stars with high temperatures shine with a brilliant blue—white light. Surface temperatures of stars range from 3000o C to 50,000o C. When these surface temperatures are plotted against luminosity, the stars fall into groups. Using the data similar to what you will plot in this activity, Danish astronomer Ejnar Hertzsprung and United States astronomer Henry Norris Russell independently arrived at similar results in what is now commonly referred to as the HR Diagram. Procedures:1. Read the Background Information 2. On the graph paper provided. Place a number next to the star according to its luminosity and surface temperature listed in the data…arrow_forwardStellar Classification and H-R Diagram Placement (40 points available). a. Where is your star located on the H-R diagram (luminosity class/region of the diagram, spectral class, luminosity/brightness)? How does this compare to that of The sun ? Discuss the inferences of the specific placement and stellar classification of your star with respect to mass, size/radius, color/temperature, composition? c. Discuss how this placement on the diagram relates to the star’s observed stage of evolution, previous evolution, and expected future evolutionary path. How does this compare to that of the Sun? d. What is the estimated total lifespan of your star and what is the estimated age of your star right now? How does this compare to that of the Sun? All of them is about Lutyen star .arrow_forwardAll massive main sequence stars reside in clouds of glowing gas. The four powerful stars in the center of the Orion Nebula are good examples. Lower mass stars like the Sun generally don't have clouds of gas around them. a. Why do powerful stars reside in gas clouds? b. What is making the gas glow exactly? For the last question, refer to the surface temperature of these stars, and to Wien's Law.arrow_forwardOur Sun is considered an "average" star. What is the average star really like? Explain. Could you go out at night and point out an average star? Why or why not?arrow_forwardTutorial Star A has a temperature of 5,000 K and Star B has a temperature of 6,000 K. At what wavelengths (in nm) will each of these star's intensity be at its maximum? If the temperatures of the stars increase, the wavelength of maximum intensity. What is the temperature (in K) of a star that appears most intense at a wavelength of 829 nm? Part 1 of 4 Wien's Law tells us how the temperature of a star determines the wavelength of maximum intensity or at what wavelength the star appears brightest. 2.90 x 106 TK If the temperature is in kelvin (K) then A is in nanometers (nm). Anm ^A = AB = = Part 2 of 4 To determine the wavelengths of maximum intensity for the two stars: 2.90 x 106 2.90 x 106 K nm nmarrow_forwardarrow_back_iosSEE MORE QUESTIONSarrow_forward_ios
Recommended textbooks for you
- 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 LearningAstronomyPhysicsISBN: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