Free Astronomy Magazine March-April 2022

29 MARCH-APRIL 2022 ASTRO PUBLISHING that signal being both periodic and frequent. To mitigate the problems from that noise, Gilbert’s team has integrated a new methodology into the planet’s search algorithms that includes modeling of stellar activity, allowing them to predict the photo- metric behavior of flares. By sub- tracting the theoretical light curve of the modeled flares from that of the star, it becomes possible to clean up the stellar photometry of some noise produced by the photospheric activity. However, this procedure is easier to describe than to apply, es- pecially if the photometry includes the co-evolution of several flares of different energies. To reduce the margin of uncertainty, the team also “injected” artificial transits into Proxima Centauri’s light curves to test the sensitivity of the method re- garding possible real transits and to determine under what circum- stances they can be detected. Once again, the result was that any tran- sits that might be occurring are not of planets with a diameter greater than 0.4 Earth diameters. Further- more, this latest study established N ASA’s Transiting Exo- planet Survey Satellite (TESS) during final tuning in the laboratory (left) and pictured as it travels its wide orbit around the Earth (below). [Orbital ATK] that the existence of transiting planets larger than Mars in the hab- itable zone of the star (where the orbital periods are 6-27 days) is ex- tremely unlikely. If, as all the research conducted in recent years seem to demonstrate, Proxima b does not pass in front of the Proxima Centauri disk, it will be necessary to take other paths to know something more about this elusive planet. Unfortunately, not even with the new Webb Space Telescope will it be possible to observe the planet directly, although we will still be able to under- stand if Proxima b has an atmosphere and, therefore, what kind of planet it is. The prerequisites for ob- taining this information are remarkable sensitivity to in- frared light (which Webb provides) and the fact that the planets orbiting in the habitable zones of red dwarfs are, likely, all gravitationally locked, meaning they always turn the same hemisphere to their star (the period of rotation on its axis and the or- bital period coincide, as happens for the Moon). It follows that Webb could detect variations in the ther- mal emissions from the planet as it moves around the star. Although not directly visible, Proxima b makes a small contribution to the total in-