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.
Best Answer: The sun has a visible disk called the photosphere, which is always present. The outer portions of that disk appear slightly darker than the middle of the disk. That is known as limb darkening and it is also always present.