Astronomy
1st Edition
ISBN: 9781938168284
Author: Andrew Fraknoi; David Morrison; Sidney C. Wolff
Publisher: OpenStax
expand_more
expand_more
format_list_bulleted
Concept explainers
Textbook Question
Chapter 18, Problem 39E
Spectral 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.
Expert Solution & Answer
Trending nowThis is a popular solution!
Students have asked these similar questions
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.
Astronomers 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…
Choose the statements that correctly describe the characteristics of the stars
located in the labeled quadrants of the H-R diagram.
Luminosity
Chapter 18 Solutions
Astronomy
Ch. 18 - How does the mass of the Sun compare with that of...Ch. 18 - Name and describe the three types of binary...Ch. 18 - Describe two ways of determining the diameter of a...Ch. 18 - What are the largest- and smallest-known values of...Ch. 18 - You are able to take spectra of both stars in an...Ch. 18 - Sketch an HR diagram. Label the axes. Show where...Ch. 18 - Describe what a typical star in the Galaxy would...Ch. 18 - How do we distinguish stars from brown dwarfs? How...Ch. 18 - Describe how the mass, luminosity, surface...Ch. 18 - One method to measure the diameter of a star is to...
Ch. 18 - We discussed in the chapter that about half of...Ch. 18 - Is the Sun an average star? Why or why not?Ch. 18 - Suppose you want to determine the average...Ch. 18 - Why do most known visual binaries have relatively...Ch. 18 - Figure 18.11 shows the light curve of a...Ch. 18 - There are fewer eclipsing binaries than...Ch. 18 - Within 50 light-years of the Sun, visual binaries...Ch. 18 - Which is easier to observe at large distances-a...Ch. 18 - The eclipsing binary Algol drops from maximum to...Ch. 18 - Review this spectral data for five stars. Which is...Ch. 18 - Which changes by the largest factor along the main...Ch. 18 - Suppose you want to search for brown dwarfs using...Ch. 18 - An astronomer discovers a type-M star with a large...Ch. 18 - Approximately 6000 stars are bright enough to be...Ch. 18 - Use the data in Appendix J to plot an HR diagram...Ch. 18 - Use the diagram you have drawn for Exercise 18.25...Ch. 18 - Use the data in Appendix I to plot an HR diagram...Ch. 18 - If a visual binary system were to have two...Ch. 18 - Two stars are in a visual binary star system that...Ch. 18 - Describe the spectra for a spectroscopic binary...Ch. 18 - Figure 18.7 shows the velocity of two stars in a...Ch. 18 - You go out stargazing one night, and someone asks...Ch. 18 - If you were to compare three stars with the same...Ch. 18 - Are supergiant stars also extremely massive?...Ch. 18 - Consider the following data on four stars: Which...Ch. 18 - If two stars are in a binary system with a...Ch. 18 - It is possible that stars as much as 200 times the...Ch. 18 - The lowest mass for a true star is 1/12 the mass...Ch. 18 - Spectral types are an indicator of temperature....Ch. 18 - We can estimate the masses of most of the stars in...Ch. 18 - In Diameters of Stars, the relative diameters of...Ch. 18 - Now calculate the radius of Sirius’ white dwarf...Ch. 18 - How does this radius of Sirius B compare with that...Ch. 18 - From the previous calculations and the results...Ch. 18 - How much would you weigh if you were suddenly...Ch. 18 - The star Betelgeuse has a temperature of 3400 K...Ch. 18 - Using the information provided in Table 18.1, what...Ch. 18 - Confirm that the angular diameter of the Sun of...Ch. 18 - An eclipsing binary star system is observed with...Ch. 18 - If a 100 solar mass star were to have a luminosity...Ch. 18 - If Betelgeuse had a mass that was 25 times that of...
Additional Science Textbook Solutions
Find more solutions based on key concepts
True or false: One watt is the unit of power equivalent to 1 joule per second.
Conceptual Integrated Science
Decide whether each statement makes sense or does not make sense. Explain clearly; because not all of these hav...
Life in the Universe (4th Edition)
You measure the capacitor and inductor voltages in a driven RLC circuit, and find 10 V for the rms capacitor vo...
Essential University Physics: Volume 2 (3rd Edition)
Fill in each blank with the most reasonable metric unit (km, m, cm, or mm).
22. The length of a football field ...
Applied Physics (11th Edition)
In which extrasolar planet system(s) (A–D) is the planet closest to the star?
Lecture- Tutorials for Introductory Astronomy
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
- Suppose you are given the task of measuring the colors of the brightest stars, listed in Appendix J, through three filters: the first transmits blue light, the second transmits yellow light, and the third transmits red light. If you observe the star Vega, it will appear equally bright through each of the three filters. Which stars will appear brighter through the blue filter than through the red filter? Which stars will appear brighter through the red filter? Which star is likely to have colors most nearly like those of Vega?arrow_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_forward12. 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 Answersarrow_forward
- = A star population is composed of stars with masses in the range between 1M and 150M. The initial mass function is = 0 (M/M)-2.3, where o (Mo). The luminosity of a star = (M/M) 3.3. Calculate the percentage of the total luminosity of the stars in the population which is produced by stars with mass between 120M and 150M. scales with its mass as L/Larrow_forward12: A star with spectral type A0 has a surface temperature of 9600 K and a radius of 2.2 RSun. How many times more luminous is this star than the Sun? (if it is less luminous enter a number less than one) Answer: 36.854 13:This star has a mass of 3.3 MSun. what is the main sequence lifetime of this star? You may assume that the lifetime of the sun is 1010 yr. Please answer question 13 thank you.arrow_forwardChoose the correct statements concerning spectral classes of stars. (Give ALL correct answers, i.e., B, AC, BCD...) A) 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. B) Hydrogen lines are weak in type O-stars because most of it is completely ionized. C) Oh Be A Fine Guy/Girl Kiss Me, is a mnemonic for remembering spectral classes. D) The spectral sequence has recently been expanded to include L, T, and Y classes. E) K-stars are dominated by lines from ionized helium because they are so hot. F) The spectral types of stars arise primarily as a result of differences in temperature.arrow_forward
- All 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_forwardA 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.arrow_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
- A star has a measured radial velocity of 300 km/s. If you measure the wavelength of a particular spectral line of Hydrogen as 657.18 nm, what was the laboratory wavelength (in nm) of the line? (Round your answer to at least one decimal place.) nm Which spectral line does this likely correspond to? Balmer-alpha (656.3 nm) Balmer-beta (486.1 nm) Balmer-gamma (434.0 nm) Balmer-del ta (410.2 nm)arrow_forwardHelp me pleasearrow_forwardUsing solar units, we find that a star has 4 times the luminosity of the Sun, a mass 1.25 times the mass of the Sun, and a surface temperature of 4090 K (take the Sun's surface temperature to be 5784 K for the sake of this problem). This means the star has a radius of.................... solar radii and is a .................... star (use the classification).arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
- AstronomyPhysicsISBN:9781938168284Author:Andrew Fraknoi; David Morrison; Sidney C. WolffPublisher:OpenStaxStars 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 Learning
Astronomy
Physics
ISBN:9781938168284
Author:Andrew Fraknoi; David Morrison; Sidney C. Wolff
Publisher: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