1. An optical instrument that blocks the bright light of the sun's disk to allow observation of the sun's corona and nearby celestial objects.
Usage: astronomy; also spelled coronagraph

Examples

• Astronomers use a coronograph to study the sun's corona during a solar eclipse.
• The space telescope is equipped with a coronograph to detect faint objects near bright stars.
• A coronograph blocks direct sunlight so researchers can observe the solar atmosphere.
• The coronograph revealed new details about the sun's outer layers.
• Modern coronographs have improved the detection of exoplanets around distant stars.