Two stars-A and B, of luminosities 0.5 and 4.5 times the observed to have the luminosity of the Sun, respectively-are same apparent brightness. Which star is more distant, and how much farther away is it than the other?

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: The surface of a star usually has the highest temperature O True O False

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Q: Two stars of the same diameter or observed to have surface temperatures of 4000 Kelvin and 16,000…

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Q: Hertzsprung-Russell Diagram Blue or blue w White Vellow Red orange Red Rioe Supergl Beteigeuse Main…

A: The region of main sequence contains large number of stars than any other region. Therefore most of…

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 star B is a 5th magnitude star and star C is 9th magnitude, what is their brightness ratio? Light…

A: Apparent magnitude of the star m is the measure of brightness of star from earth. Brightness is also…

Q: A star is observed at a distance of 90 pc. What will be its parallax angle?

A: Parallax is defined as the change in the apparent position of an object due to a change in the…

Q: Star A has an effective temperature of TA = 7200 K and a radius of RA = 2.04R, asecond star, Star…

A: Let LA be defined as the luminosity of star A and LB be defined as the luminosity of star B. The…

Q: Favorite Star Polaris is 132 pc from Earth and has an apparent magnitude of 2.5. What is its…

A: When the brightness of a star is measured there are two ways, Apparent and absolute magnitudes.…

Q: What star has the largest stellar parallax as measured from opposite ends of the Earth's orbit about…

A: Parallax is the apparent displacement of an object because of a change in the observer's opinion.…

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: sequence

A: Hertzsprung-Russell's diagram clearly shows that the star spends most of its life as a main-sequence…

Q: Using the proportionality relationships for stellar luminosity as a function of mass and stellar…

A: Stellar lifetime is directly proportional to Stellar mass. Stellar luminosity is inversely…

Q: Two stars have the exact same luminosity, but star Y is four times dimmer looking that star X. This…

A: Basic Details Two stars star X and star Y have same luminosity. The brightness of the star is…

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: Suppose the distance to a star is doubled. Then the luminosity of the star is O Remains the same,…

A: Luminosity and apparent brightness are 2 different things. Luminosity is unique property of body and…

Q: Star A has an apparent magnitude of –1.5 and is 12.6 light-years from Earth. Star B has an apparent…

A: Given: dA=12.6ly=3.863parsec, dB=15.6ly=4.783parsec, mvA=-1.5, mvB=0.4 The apparent magnitude of a…

Q: Why do distant stars look redder than their spectral types suggest?

A: The pace is mostly empty but there are areas of large density of the interstellar medium.   It…

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: 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: 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: If a T Tauri star is the same temperature as the sun but is ten times more luminous, what is its…

A: The energy radiated by a star per second is known as its luminosity and is directly proportional to…

Q: What is the color of the stars shown on the diagram that have the lowest surface temperature? O red…

A: Required: Color of the stars,

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: You measure a star to have a parallax angle of 0.12 arc-seconds What is the distance to this star in…

A: Write the given values of the problem- Parallax angle=0.12 arc-second

Q: Compute the distance to the following stars using the luminosity-distan relationship: m-M=5 log (d)…

A: Apparant Magnitude (m) = 9.95Absolute Magnitude (M) = 0.75

Q: Sirius is the brightest star in the sky (but is located in the Southern hemisphere). It has a…

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Q: Let us imagine that the spectrum of a star is collected and we find the absorption line of…

A: Since            ∆λ/λ   = v/c where  c = 3*10-8m/s v    = velocity of star…

Q: Integrate the first equation over all wavelengths to find an expression for the total luminosity of…

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