Foundations of Astronomy (MindTap Course List)
Foundations of Astronomy (MindTap Course List)
14th Edition
ISBN: 9781337399920
Author: Michael A. Seeds, Dana Backman
Publisher: Cengage Learning
bartleby

Concept explainers

Question
Chapter 12, Problem 6P
To determine

The lifetime of main-sequences of Star A compared to the sun.

The lifetime of main-sequences of Star B compared to the sun.

The luminous of main-sequences of Star A compared to the sun.

The luminous of main-sequences of Star B compared to the sun.

Expert Solution & Answer
Check Mark

Answer to Problem 6P

The lifetime of main-sequences of Star A compared to the sun is 4×106solarlifetimes.

The lifetime of main-sequences of Star B compared to the sun is 600solarlifetimes.

The luminous of main-sequences of Star A is 4×107times more luminous than the sun.

The luminous of main-sequences of Star B is 1×104times luminous as the sun.

Explanation of Solution

Write the expression for the stellar life expectancies of star A.

    t*A=1M*A2.5        (I)

Here, t*A is the stellar life expectancy of star A, M*A is the luminosity of the main-sequence star A.

Rewrite the above expression for luminosity of star A.

    L*A=M*At*A        (II)

Here, L*A is luminous of main-sequences of Star A.

Write the expression for the stellar life expectancies of star B.

    t*B=1M*B2.5        (III)

Here, t*B is the stellar life expectancy of star B, M*B is the luminosity of the main-sequence star B.

Rewrite the above expression for luminosity of star B.

    L*B=M*Bt*B        (IV)

Here, L*B is luminous of main-sequences of Star B.

Conclusion:

Substitute 150 for M*A in (I) to find t*A

    t*A=1(150)2.5=3.63×1064×106solarlifetime

Substitute 150 for M*A, 4×106solarlifetime for t*A in (II) to find L*A.

    L*A=1504×106=3.75×1074×107times

Substitute 0.08 for M*B in (III) to find t*B

    t*B=1(0.08)2.5=552.43600solarlifetime

Substitute 0.08 for M*B, 600solarlifetime for t*B in (IV) to find L*B.

    L*B=0.08600=1.33×1041×104times

Therefore, the lifetime of main-sequences of Star A compared to the sun is 4×106solarlifetimes. The lifetime of main-sequences of Star A compared to the sun is 600solarlifetimes. The luminous of main-sequences of Star A is 4×107times more luminous than the sun.  The luminous of main-sequences of Star B is 1×104times luminous as the sun.

Want to see more full solutions like this?

Subscribe now to access step-by-step solutions to millions of textbook problems written by subject matter experts!
Students have asked these similar questions
Assume that an O main-sequence star (40,000 K) and a G main-sequence star (5,500 K) have the same radius. How many times brighter is the O star? LO LG  =   Star B is located 2.6 times farther from earth than Star A, but both have the same apparent visual magnitude of 1 mag. Which star is intrinsically brighter?How many times brighter is the star?   If a star has an apparent magnitude equal to its absolute magnitude, how far away is it in parsecs? pc
A 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 years
For a main sequence star with luminosity L, how many kilograms of hydrogen is being converted into helium per second? Use the formula that you derive to estimate the mass of hydrogen atoms that are converted into helium in the interior of the sun (LSun = 3.9 x 1026 W). (Note: the mass of a hydrogen atom is 1 mproton and the mass of a helium atom is 3.97 mproton. You need four hydrogen nuclei to form one helium nucleus.)
Knowledge Booster
Physics
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
  • According to the text, a star must be hotter than about 25,000 K to produce an H II region. Both the hottest white dwarfs and main-sequence O stars have temperatures hotter than 25,000 K. Which type of star can ionize more hydrogen? Why?
    We will take a moment to compare how brightly a white dwarf star shines compared to a red giant star. For the sake of this problem, let's assume a white dwarf has a temperature around 10,000 K and a red giant has a temperature around 5,000 K. As for their stellar radiatin, the white dwarf has a radius about 1/100th that of the Sun, and a red giant has a radius around 100 times larger than the Sun. With this in mind, how does the luminosity of a red giant star compare to that of a white dwarf (Hint: do not try to enter all of these numbers into the luminosity equation {it won't go well}; instead, remember that you are only interested in the ratio between the two, so all common units and components can be divided out)? Please enter your answer in terms of the luminosity of the red giant divided by the luminosity of the white dwarf and round to two significant figures. Also, please avoid using commas in your answer.
    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) This star has a mass of 3.3 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. Compare this to the lifetime of a A0 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.)
    Recommended textbooks for you
  • Foundations of Astronomy (MindTap Course List)
    Physics
    ISBN:9781337399920
    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
    Astronomy
    Physics
    ISBN:9781938168284
    Author:Andrew Fraknoi; David Morrison; Sidney C. Wolff
    Publisher:OpenStax
  • The Solar System
    Physics
    ISBN:9781337672252
    Author:The Solar System
    Publisher:Cengage
    Stars and Galaxies
    Physics
    ISBN:9781305120785
    Author:Michael A. Seeds, Dana Backman
    Publisher:Cengage Learning
  • Foundations of Astronomy (MindTap Course List)
    Physics
    ISBN:9781337399920
    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
    Astronomy
    Physics
    ISBN:9781938168284
    Author:Andrew Fraknoi; David Morrison; Sidney C. Wolff
    Publisher:OpenStax
    The Solar System
    Physics
    ISBN:9781337672252
    Author:The Solar System
    Publisher:Cengage
    Stars and Galaxies
    Physics
    ISBN:9781305120785
    Author:Michael A. Seeds, Dana Backman
    Publisher:Cengage Learning