co·​ro·​na·​graph kə-ˈrō-nə-ˌgraf How to pronounce coronagraph (audio)
variants or less commonly coronograph
plural coronagraphs also coronographs
: a telescope for observation of a star's corona
The American spacecraft was to carry the solar coronagraph, the only instrument on the mission capable of imaging the sun's polar regions …M. Mitchell Waldrop
Using an instrument called a coronagraph, the astronomers can block a star's light, to catch the dim glow of dark matter that may surround it.Jonathan Weiner

Examples of coronagraph in a Sentence

Recent Examples on the Web That’s because the wave nature of light means that some excess light from the host star will always spill out past the coronagraph, degrading the image. Dan Falk, Smithsonian Magazine, 29 Jan. 2024 This spacecraft will travel to an orbit around the L1 Lagrange point nearly a million miles (1.5 million kilometers) on the Sunward side of the Earth, where Aditya-L1 will use a solar telescope and coronagraph to observe the Sun and a suite of sensors to measure the solar wind. Stephen Clark, Ars Technica, 31 Aug. 2023 But a separate spacecraft is a much more complex and unwieldy starlight-suppression solution than a coronagraph and thus is unlikely to be part of HWO from the get-go. Jonathan O'Callaghan, Scientific American, 6 Dec. 2023 The performance of Roman’s coronagraph will provide crucial information for HWO’s grander aspirations. Jonathan O'Callaghan, Scientific American, 6 Dec. 2023 The space agency’s follow-up mission to Webb, the Nancy Grace Roman Space Telescope, will also carry a coronagraph as a technology demonstration that could (with certain tweaks now being actively considered) potentially snap pictures of the candidate. Lee Billings, Scientific American, 10 Feb. 2021 Near-Infrared Camera (NIRCam): The only near-infrared instrument with a coronagraph, NIRCam will be a key instrument for studying exoplanets whose light would otherwise be drowned out by their nearby star’s glare. Jen Christiansen, Scientific American, 1 Dec. 2022 The Last Speech Boris Johnson Made Before Stepping Down As Prime Minister Webb achieved its exoplanet photography feat thanks to a coronagraph built into its various imaging instruments, which blocks out the starlight, revealing anything that is orbiting the star. Jeffrey Kluger, Time, 2 Sep. 2022 The researchers got a clear look at the young star and its disc of dust by using an instrument called the Spectro-Polarimetric High-contrast Exoplanet Research, or SPHERE, which uses a coronagraph to block out the star itself and make the surrounding system visible. Theresa MacHemer, Smithsonian Magazine, 22 May 2020 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'coronagraph.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


corona + -graph

First Known Use

1884, in the meaning defined above

Time Traveler
The first known use of coronagraph was in 1884

Dictionary Entries Near coronagraph

Cite this Entry

“Coronagraph.” Dictionary, Merriam-Webster, Accessed 23 Feb. 2024.

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