Noun. 1. invariant-a feature (quantity or property or function) that remains unchanged when a particular transformation is applied to it. characteristic, feature-a prominent attribute or aspect of something; the map showed roads and other features; generosity is one of his best characteristics.
The part of the sun that is going to emit the most visible light is going to be the Photosphere.he photosphere is the layer of the sun that emits visible light.  The light is emitted by hydrogen atoms and is bright red. Edit. Share to: Answered. In Astronomy.
While the sun does emit  ultraviolet radiation, the majority of solar energy comes in the form of light and heat, in the visible and infrared regions of the electromagnetic spectrum. As shown in Table 2, visible light spans the relatively narrow range of 0.4 to 0.9 Âµm (or 400 to 700 nm).