Spectra and Electron Orbits

Went for my evening walk listening to the rest of lesson 3. It was about how electrons in orbit around a nucleus get excited by photons and change orbits depending on how much energy the photon carries. Depending on which frequency the photon and orbit of the electron determines what frequency the electron can accept and the orbit the electron will jump to. The spectra of a star can help in finding out the star’s makeup, if it is moving towards or away from the observer, and if it is a binary system it can tell the mass of the two stars and their period. I’ll have to delve more into this!