On some astronomical images, stars appear with lines coming out of a central circle.
Stars are point sources, even for the closest stars.
You observe a prominence on the sun and measure that it has a flux of 1.4 Watts per square meter. You observe a star with a spectrograph. Strangely, another time you observe the star, you notice that the shift is -0.1 nanometers. Determine the number of hydrogen atoms in this layer. Now, if the layer is at 5800 Kelvin as specified above, determine the ratio of atoms in the 3rd excited state to that in the second excited state.