A helioscope is an instrument used to observe the sun. Synonyms for helioscope include solarscope, sunscope, solar viewer, sun viewer, solar telescope, and sun telescope. These instruments are used for studying solar activity, including sunspots, solar flares, and coronal mass ejections. Helioscopes can range in size from handheld devices to large observatory telescopes. They allow scientists and astronomers to observe the sun in different wavelengths of light, including visible light, ultraviolet light, and X-ray radiation. By studying the sun with a helioscope, scientists can learn more about the workings of our solar system and the impact of solar activity on Earth.