Cinema 4d sun with loopable (300 frames) animated surface and ring texture.
It comes with After Effects file used to create loopable texture.
So you can create different versions of textures on your own.

It comes with 1K animated texture and After Effects comp that
is set up to render 3K animated texture (I did not attach 3K texture because of it size.

Cinema 4d file has all main sun layers (Chromosphere, Photosphere, Convective, Radiative, Core)
Layers can be present in slices via booleans (booleans are used to hide/show layers of the sun)

Main layer (Chromosphere) is made as animated texture (image sequence rendered from After Effects project included),
so you can use it in any 3d software.
All other layers are made of procedural shaders and can be used only in Cinema 4d.