Print ViewBlackbody Radiation and Continuous Spectra

In summary, The astronomer is trying to estimate the surface temperature of a star with a radius of 5.0* 10^8m by modeling it as an ideal blackbody. They have measured the intensity of radiation at a distance of 2.5* 10^{13}m to be 0.055 W/m^2 and are using the equation P=4pir^2*s*T^4 to solve for the temperature. They also mention using the Stefan-Boltzmann constant in their calculations.
  • #1
Sasa888
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Homework Statement



An astronomer is trying to estimate the surface temperature of a star with a radius of 5.0* 10^8m by modeling it as an ideal blackbody. The astronomer has measured the intensity of radiation due to the star at a distance of 2.5* 10^{13}m and found it to be equal to 0.055 W/m^2. Given this information, what is the temperature of the surface of the star?

My attempt:

I tried using I(labda)= 2*pi*h*c² /labda^5*(e^(hc/labda*k*T)-1)
But ik keep getting stuck.. I don't know what to do with the radius of the star nor do i know what to do with the distance between the star and the measurement of I..
 
Last edited:
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  • #2
Don't worry about the wavelength dependence. There's an equation for the total power-per-surface-area of a blackbody at temperature T. You can use that, plus the total surface area of the star, to get started.
 
  • #3
Are you talking about:
P=4pir^2*s*T^4

Where s is the Stefan Bolzmann constant ??
Because now i don't know what to do with the distance given from th star to the place of the measurement..
 

Related to Print ViewBlackbody Radiation and Continuous Spectra

1. What is blackbody radiation?

Blackbody radiation is the electromagnetic radiation emitted by a perfect blackbody, which is an object that absorbs all radiation that falls on it and emits radiation at all wavelengths and intensities.

2. What is the difference between blackbody radiation and continuous spectra?

Blackbody radiation refers to the specific type of radiation emitted by a perfect blackbody, while continuous spectra refer to the range of wavelengths and intensities of all possible electromagnetic radiation emitted by an object. Blackbody radiation is a type of continuous spectrum, but not all continuous spectra are blackbody radiation.

3. How does temperature affect blackbody radiation?

The temperature of a blackbody directly affects the wavelength and intensity of the radiation it emits. As the temperature increases, the peak of the radiation shifts to shorter wavelengths and the intensity increases. This is known as Wien's displacement law.

4. Why is blackbody radiation important in understanding the universe?

Blackbody radiation is important because it allows us to study the properties of objects in the universe based on the radiation they emit. By analyzing the spectrum of blackbody radiation, scientists can determine the temperature and composition of objects such as stars and planets.

5. How is blackbody radiation related to Planck's law?

Planck's law describes the spectrum of electromagnetic radiation emitted by a blackbody at a given temperature. It states that the intensity of the radiation at a specific wavelength is proportional to the temperature and follows a specific mathematical formula. This law is essential in understanding blackbody radiation and is often used in various fields of science, such as astrophysics and thermodynamics.

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