Occulting disk

{{Short description|Disk used in telescopes to block a bright object}}

File:Debris disk AU Mic HST.jpg. The black circle in the center is an occulting disk of a coronagraph.]]

An occulting disk is a small disk placed centrally in the eyepiece of a telescope or at its focal point, to block the view of a bright object so that fainter objects can be seen more easily.{{cite web |title=Occulting disk - Oxford Reference |url=https://www.oxfordreference.com/display/10.1093/oi/authority.20110803100244467 |website=Oxford Reference |publisher=Oxford University Press |access-date=28 August 2023}}{{cite book |last1=Ridpath |first1=Ian |title=A Dictionary of Astronomy |date=2012 |publisher=Oxford University Press |page=336 |isbn=9780199609055 |url=https://books.google.com/books?id=9780199609055 |access-date=28 August 2023}}

The coronagraph, at its simplest, is an occulting disk in the focal plane of a telescope, or in front of the entrance aperture, that blocks out the image of the solar disk, so that the corona can be seen. Starshade is one designed to fly in formation with a space telescope to image exoplanets.