Gwynney's "Stardust" compares a loved one's love to stars, then watches that comparison fall apart. In the first stanza, the love is a comfort: it lights up the night, gives hope when the speaker feels broken, and shines through the hardest moments. The tone is warm and grateful.
Then the poem shifts. The love becomes dust, something small and weightless that fades slowly and gets carried off by the wind. The line about having "no plans to come back" is the most painful, because it suggests the person who is leaving won't return. The speaker seems to be left with only what remains.
The final stanza joins the two images together. A star that "easily" fades and turns into dust suggests that something once bright and hopeful was more fragile than it looked. The mood moves from hope to sadness and loss. The title, "Stardust," holds both ideas at once: what was beautiful and what is left behind when it's gone.