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 to detect UV light and responds maximally to ultraviolet light at approximately 350 nm. Therefore, a visual pigment that responds to ultraviolet light is the mechanism behind ultraviolet light perception. White Cabbage Butterflies, "Pieris rapae crucivora", use their private ultraviolet communication system to initiate mating behavior. In this species, ultraviolet reflection is sexually dimorphic with females exhibiting the ability to reflect ultraviolet light of 380 nm to 400 nm and males being less able to reflect UV. Males who perceive an ultraviolet reflection from a female initiate a courtship behavior that involves approaching the female and attempting to copulate. Females