What is the equation/Formula for finding the luminosity of a star in Solar Luminosities?
Please explain clearly and write what each letter represents
say a star was 5 time larger than the sun and it had a temperature of 8,000 kelvin, what would be the luminosity of this stars is L_sun?
ronwizfr
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The formula for the Luminosity L = Area * Energy Flux = 4pi R^2 * sigma T^4, where R is the radius and T the temperature. The second factor is of course the Stefan-Boltzman law.
As my computer doesn't like Greek letters, and because I always forget the values of these pesky constants, I prefer to write: L/L_Sun = (R/R_Sun)^2 (T/T_Sun)^4
In this case L/L_Sun= 5^2 (8000/5780)^4 = 91.7
So L = 91.7 L_Sun.
Anonymous
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What is the Formula for Determining the luminosity of a star?
What is the equation/Formula for finding the luminosity of a star in Solar Luminosities?
Please explain clearly and write what each letter represents
say a star was 5 time larger than the sun and it had a temperature of 8,000 kelvin, what would be the luminosity of this stars is L_sun?
?
Luminosity Equation
blakut
Luminosity means the total energy radiated by a body (star) per second. Luminosity is L= Flux x Area of a body. Assuming that 5 times larger than the Sun means 5 times the surface of the Sun, you get:
L_star = 5 x Solar surfaces x sigma x (8000)^4.
sigma = Stefan Boltzmann constant 5.67x10^(-12)
sigma x (T)^4 means energy radiated per second per unit area by a body at temperature T.
L_star= 4pi x (R_star)^2 x sigma x (T_star)^4.
Where R_star = Radius of the star. T_star = Temperature of the star.
You need to know the output of the sun or the temperature of the sun for this problem though.
Anonymous
luminosity = 4 * π * R² * S * T^4 'R' radius of star 'S' Stephan Boltzman Constant (5.6703 10-8 (W/m2K4)) 'T' temperature of star Luminosity of star = 1.793 Joules/second (Watts)