If a star has M = 100Msun and L = 10^6Lsun, how long can it shine at that luminosity if it started as pure hydrogen and is able to convert 10% of its H to He? If a star has M = 0.5Msun and L = 0.1Lsun, how long can it shine under the same conditions?

Q: Suppose we measure the flux of a star to be F = 9.47 x 10-10 W m-2, and suppose the star is at a…

A: Luminosity is a measure of total electromagnetic power at all wavelength radiated by any star or…

Q: Many of the bright stars in the night sky are highly luminous normal blue stars (such as Acrux), and…

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Q: At what wavelengths do stars of surface temperates 20 000 K, 10 000 K, and 3000 K have their peak…

A: Given temperatures as below :- Temperature (T) = 20000 K. Temperature (T) = 10000 K. Temperature (T)…

Q: A star has a surface temperature of T = 10,000 K and a radius three times that of the Sun, R = 3R…

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Q: A star is known to be moving at 7.87km/s toward the earth. If you observe the spectral line to be at…

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Q: If a star has a surface temperature 2 times lower than the Sun's and a luminosity the same as the…

A: Given, If To is the surface temperature of the sun, Lo is the luminosity of the sun Then for the…

Q: If a star has a radius 2 times larger than the Sun's and a luminosity 1/4th that of the Sun, how…

A: Given that Radius of star, R = 2  luminosity of the star ,

Q: d²p GMp %3D dt2 (a² + p2)3/2* 2. Suppose that p < a, that is, the star is deep inside the cluster.…

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Q: Find the wavelength of peak intensity for a hot 45000 K star that emits thermal radiation.

A: Given that:Temperature of the hot star : (T) =45000 K  Now,         From Wien’s displacement Law…

Q: Find the speed for a star in which this line appears at wavelength 121.8 nmnm. Express your answer…

A: Given that-- (lemda)star = 121.8 nm (lemda) = 121.6 nm Speed of light (c) = 3 × 108 m/s Question?…

Q: At rest hydrogen has a spectral line at 149nm. If this line is observed at 144nm for the star…

A: Given:hydrogen spectral line at rest, λs = 149 nmobserved spectral line, λ = 144 nmAsked:What is the…

Q: If a neutron star has a radius of 9.12 km and a temperature of 3.63 x 106 K, how luminous is it in…

A: 1)Using stefan's lawP = σ A T4Where P is the power σ is the stefan's constant A is the area of…

Q: To find the Sun’s luminosity from its brightness using the inverse-square law, you also had to be…

A: The distance to the sun can be calculated using the method of parallax. Parallax is defined as the…

Q: At rest, hydrogen has a spectral line at 144 nm. If this line is observed at 168 nm for the star…

A: Given that Hydrogen has a spectral line at λ= 144 nm =10-9m This line is observed at λ'= 168 nm=10-9…

Q: Consider two stars, A and B, of equal size. You take a spectrum of each star and find that the flux…

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Q: What characterizes a star of spectral-type A in the visible part of the spectrum? Strong lines…

A: Spectral type A has wavelength ranging from 290-390 nm. They have very strong hydrogen lines.

Q: at what wavelength (in nm) will it radiate the most energy? Is this a cool or hot star?

A: According to Wien's displacement law  The peak wavelength relation is given as    Peak wavelength =…

Q: The density of Sirius B is 2×106 g/cm3 and its mass is 1.95×1030 kg. What is the radius of the white…

A: The given data are: ρ=2×106 g/cm3=2×109 kg/m3m=1.95×1030 kg Here, ρ and m represent the density and…

Q: At what wavelengths do stars of surface temperates 20 000 K, 10 000 K, and 3000 K have their peak…

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Q: What is the luminosity of a star having three times the radius of the Sun and a surface temperature…

A: The luminosity of a star is a measure of the total amount of energy that is radiated by a star per…

Q: If the hottest star in the Carina Nebula has a surface temperature of 51,000 K, at what wavelength…

A: Concept: "The Wien's displacement law states that the wavelength carrying maximum energy is…

Q: What measurements would you make (assuming you have the money, time, & equipment) to determine a…

A: In this question we have to answer what measurements we will make to determine the surface…

Q: What characteristics must a binary star have to be a good candidate for a black hole? Why is each of…

A: The characteristic must a binary star posses for it to be a good candidate for black hole is,  From…

Q: and is 10^16m distant from us, what would we measure its brightness to be? If we then moved that…

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Q: ou observe a star with a telescope over the course of a year. You find that this star has a flux…

A: .In vertical direction:psinθ=40sin60Psinθ=4032Psinθ=34.6410 free body diagram:

Q: Imagine that you are observing a star and you find the wavelength of peak emission for the star to…

A: required:)wavelength of peak emission for a new star having temperature one third of original star.

Q: Consider two stars A and B, with apparent magnitudes mA = 3 and mB = 13. How much brighter (in…

A: Given, mA = 3    and mB = 13 Now, the difference in apparent magnitude is                 n = mB -…

Q: What is the wavelength in micrometers  of peak emission for a black body at 33.5°C? (c = 3.0 × 108…

A: Given values:Temperature of the black body:T = 33.5°C = 306.65 K Wein's displacement law:We know…

Q: The total luminosity of the Sun is 4e26 Watts. a) What is the mass (in kg) that the Sun loses each…

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Q: As we read in the book, a star that appears to be 1 magnitude brighter will have approximately 2.5…

A: Required : Approximate ratio of the flux.

Q: In a laboratory, the Balmer-beta spectral line of hydrogen has a wavelength of 486.1 nm . If the…

A: Wavelength of (λ°) = 481.6 nm Difference of wavelength ∆ λ = λ- λ° = 486.1- 485.8 =  0.3 nm Speed of…

Q: The time it would take for the Sun to consume all its hydrogen (if the Sun's luminosity remained…

A: All-stars like our Sun are powered by nuclear fusion. It is a nuclear reaction in which two lighter…

Q: 5) Let's use this expression to solve a problem. Star X and Star Y are intrinsically identical…

A: Given, star X is located 20 light-years from earth star Y is located 40 light-years  from earth…

Q: Consider the following question: How many times bigger than the sun would a cool star (4000K) have…

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Q: For a star with surface temperature 5,100 K, what is the peak frequency of light from the sun?…

A: Given Surface temperature of star T =5100 K We have to find the peak frequency of light from the sun