Question

Use the following equation to help you.

The blackbody curve for a star named Theta is shown below. What is the surface temperature of this star rounded to the nearest whole number?



800 K
52,870 K
23,200 K
36,250 K

Answer 1

Answer: 36,250 K

Step-by-step explanation:

We are given the equation:

`T_K=\frac{2.9 * 10^6 \text{nm(K)}}{\lambda_\text{peak}}`

But, what does each variable mean?

`T_K` is the temperature of the star in Kelvin (K).

`\lambda_\text{peak}` is the wavelength that has the highest intensity (the mountain "peak").

nm(K) just show the units (they aren't used in the calculation).

So, the only thing we need to figure out is
`\lambda_\text{peak}`. From the second picture you attached, we see that the highest peak happens somewhere between 50 and 100 nm... let's see here... putting a ruler on my screen... and... yep! Looks like my best guess is 80 nm for the location of the highest peak.

So, plugging in
`\lambda_\text{peak} = 80 \text{ nm}` we get:

`T_K = (2.9 * 10^6)/(80) = 36,250`

The estimated surface temperature of the star is 36,250 K.