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.
There is not really a 'surface' to the Sun, but this is the layer that we see that looks like it is the surface. The fifth layer of the sun traveling outward from the core is the chromosphere, a red layer of the sun that is 1,000 miles thick. This thicker layer of the sun emits light in the red part of the visible spectrum. The temperature rises greatly here, which is unique.