Question

A star has surface temperature of 25000 K. Which lines would be prominent in its
spectrum and why?

Answer 1

Answer on Question #61090-Physics-Astronomy-Astrophysics

Star has surface temperature of 25000 K. Which lines will be prominent in its spectrum? Justify your answer.

Solution

The peak wavelength in the star spectrum ($\lambda_{max}$, m) may be derived from the effective temperature of the star's surface according to the Wien's displacement law, if we assume that the spectrum of star is close to the blackbody spectrum.

Then, $\lambda_{max} = \frac{(2.898 \cdot 10^{-3})}{T}$, where $T$ – absolute temperature of the star's surface, K.

From Wien's law we can calculate the peak wavelength ($\lambda_{max}$) for a star with the surface temperature 25000 K:

$$\lambda_{max} = \frac{(2.898 \cdot 10^{-3})}{25000} \approx 120 \cdot 10^{-9} \, m = 120 \, \text{nm}.$$

Answer: 120 nm.

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