Example output
I can provide image ideas based on this article and a general understanding of this topic. Let me provide the three image ideas as per your instructions.
Header Image:
A star subtly transitioning through different stages of brightness and color, with a measurement tool (like a telescope) observing it from a distant planet.
Inset Image 1:
An astronomer studying a complex star chart, with various stars highlighted in different colors, representing different ages or stages in their lifecycle.
Inset Image 2:
A split scene of a young bright star on one side and an older, dimmer star on the other, with a clock face or hourglass between them to signify the passage of time.