Visible-light astronomy Visible-light astronomy Visible-light astronomy encompasses a wide variety of observations via telescopes that are sensitive in the range of visible light (optical telescopes). Visible-light astronomy is part of optical astronomy, and differs from astronomies based on invisible types of light in the electromagnetic radiation spectrum, such as radio waves, infrared waves, ultraviolet waves, X-ray waves and gamma-ray waves. Visible light ranges from 380 to 750 nanometers in wavelength. Visible-light astronomy has existed as long as people have been looking up at the night sky, although it has since improved in its observational capabilities since the invention of the telescope, which
Ultraviolet communication in butterflies some species this distinction is not seen at all times, and UV patterns may vary visually depending on the position of reflecting light. This can be seen in the common brimstone, where males will exhibit male or female patterns of iridescence with different positions, distances, and angles of light - this is known as the "gynandromorphic" effect. The ultraviolet communication system employed by butterflies is also used an indicator of male sex to other rival males in the butterfly, "Colias eurytheme". In this species, only males are able to reflect ultraviolet light off the dorsal side of their wings, while