A coronagraph is a scientific instrument that is used to study the sun, specifically the outer atmosphere, or corona. There are synonyms for the word coronagraph that can be used interchangeably, depending on the context. Some common synonyms include helioscope, solar telescope, solar coronal imager, and solar observatory. Each of these instruments is designed to study different aspects of the sun's corona. While some coronagraphs are designed for space-based observations, others are ground-based and can capture images and data from the earth's surface. Regardless of their design and function, all coronagraphs help scientists better understand the dynamics of the sun and its impact on our planet.