What phenomenon refers to the gradual fading of light in the western sky after sunset, separate from Venus's glare?

Answer

The afterglow

The afterglow is the separate phenomenon resulting from sunlight scattering off atmospheric particles high above the observer after the Sun has set, leading to a gradual reduction in overall sky brightness.

What phenomenon refers to the gradual fading of light in the western sky after sunset, separate from Venus's glare?
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