The Photons Must Get Through – Radiative Transfer
If starlight shone clear and uninterrupted across light years of space and shone just as clear down through Earth’s atmosphere into our telescopes, life for both professional and amateur astronomers would be much simpler, though possibly nowhere near as interesting. However, a great deal can and does happen to our river of starlight before it reaches our telescopes and detectors. In fact, even before that starlight can leave the photosphere it has to get from its source – the nuclear reactor core at the heart of the star – to the star’s surface layers. This is a relatively short journey in terms of distance but by far the longest in terms of time, and much depends on the very structure and composition of the star itself.