Question

Since we cannot physically collect data from stars and most other objects in the universe, almost all of the information we obtain from the universe comes from analyzing the light, or spectra, from those objects. The study of light is known as spectroscopy. As we have seen in this simulation, every blackbody emits light with an easily identified pattern known as the blackbody curve. This is the particular way the total light emitted by a blackbody varies with its frequency. The exact form of the curve depends only on the body's temperature. Since we can treat stars as blackbodies, this is incredibly useful in astronomy that shows us that the color of a star is also indicative of its temperature. Use the simulation to determine the surface temperature of the following star: Betelgeuse is a red supergiant star in the constellation Orion. Knowing that Betelgeuse has peak intensity in the red and infrared wavelengths, adjust the intensity scale and temperature until you can determine the approximate surface temperature of the star. a. 3500K b. 4800K c. 7700K d. 11,000 K

Answer 1

Answer:

3500 K

Explanation:

b = Wien's displacement constant = $2.89\times 10^{-3}\ mK$

Wavelength range = 700 nm to 10⁶ m. Let us take 825 nm

$\lambda_m=825\ nm$

From Wien's displacement law we have

$\lambda_m=\dfrac{b}{T}\\\Rightarrow T=\dfrac{b}{\lambda_m}\\\Rightarrow T=\dfrac{2.89\times 10^{-3}}{825\times 10^{-9}}\\\Rightarrow T=3500\ K$

The surface temperature of Betelguese is 3500 K