Detail this asset from Unity Store: Original Link
This is a paid asset, but now you can download Sun Free.
Animated Sun is an simple animated texture model, it comes with easy to use scripts to achieve the animated effect.
• 2048px High Quality Animated Textures
• 2x flares with unique appearance
• Animated glow effects
Compatible with Unity 5.1 up to new versions of Unity(2020+)
Support available for assistance if any problems should occur.