Direct Imaging of Exoplanets

Over the past 4 decades, the exploration of planets beyond our solar systemhas yielded the discovery of over 5600 exoplanets orbiting different stars.Continuous advancements in instrumentation and cutting-edge techniques empowerastronomers to unveil and characterize new exoworlds with increasing frequency.Notably, direct imaging, also called high-contrast imaging (HCI), stands out asthe only method capable of capturing photons emitted directly from theplanetary bodies. This innovative technique proves particularly advantageousfor scrutinizing nascent planetary systems, where planets shine brilliantly andemit significant heat during their initial developmental phases. HCI providescomprehensive visuals of the entire system, encompassing the central star,potential circumstellar disks, and any additional companions. However, thecomplexity of imaging an object 10^6 fainter than its parent star necessitatesstate-of-the-art instrumentation. HCI demands cutting-edge tools such as exAOsystems, telescopes exceeding 8 meters in diameter, coronagraphs, and modernimagers. The pivotal role of post-processing cannot be overstated in the questfor detecting and characterizing planets through HCI. This method has not onlyfacilitated the discovery of numerous planets but has also presented invaluableopportunities to explore the properties of young substellar companions, bothplanets and brown dwarfs. Insights into their interactions with parent disks orother companions within the system, the composition of their atmospheres, andthe identification of still accreting planets, also known as "protoplanets,"contribute significantly to our understanding of planet formation scenarios.The continued refinement of HCI promises to unveil further revelations in thecaptivating field of exoplanetary exploration.