Editing Exoplanet (section)

=== Direct imaging ===
[[File:Betapic orbit v2 reduced.gif|alt=Two directly imaged exoplanets around star Beta Pictoris, star-subtracted and artificially embellished with an outline of the orbit of one of the planets. The white dot in the center is the other exoplanet in the same system.|thumb|Directly imaged planet [[Beta Pictoris b]], with an edge-on orbit as seen from Earth]]
Planets are extremely faint compared to their parent stars. For example, a Sun-like star is about a billion times brighter than the reflected light from any exoplanet orbiting it. It is difficult to detect such a faint light source, and furthermore, the parent star causes a glare that tends to wash it out. It is necessary to block the light from the parent star to reduce the glare while leaving the light from the planet detectable; doing so is a major technical challenge which requires extreme [[optothermal stability]].<ref name="Perryman_book11">{{Cite book|last = Perryman|first = Michael|title = The Exoplanet Handbook|url = https://archive.org/details/exoplanethandboo00perr|url-access = limited|publisher = Cambridge University Press|date = 2011|page = [https://archive.org/details/exoplanethandboo00perr/page/n162 149]|isbn = 978-0-521-76559-6}}</ref> All exoplanets that have been directly imaged are both large (more massive than [[Jupiter]]) and widely separated from their parent stars.

Specially designed direct-imaging instruments such as [[Gemini Planet Imager]], [[VLT-SPHERE]], and [[Subaru Telescope#Subaru Coronagraphic Extreme Adaptive Optics system|SCExAO]] will image dozens of gas giants, but the vast majority of known extrasolar planets have only been detected through indirect methods.