Hello! This is my first post so forgive any errors of decorum. ) I am a student working toward a degree in astrophysics but I'd like to jump a few years ahead when it comes to the study of exoplanets. While examining some data about the new discovery of Kepler-22b, I noticed a plotted data set described as a "flux time series after [the] removal of a second-order polynomial for each segment and normalizing the data of each quarter by the median" (see Figure 1 here). I'd like to better understand what this means. Any guidance, links, or direction would be greatly appreciated. I understand a flux time series is, of course, a measure of the light arriving from the star as plotted over time but I do not understand the process of removing polynomials and normalizing the data or the value of doing these things. My assumption is that this involves some sort of reverse local regression. Thank you in advance for any contribution to my efforts.