The speaker tells of "a certain star" of which he knows nothing except that "it can throw" beautiful red and blue darts of light. Because of his enthusiasm, his friends ask to see it.
But when they look, it stops. The friends instead fix their attention on Saturn, which sits "above" the star. The poet is unfazed by their disinterest, for his star "has opened its soul to [him]" and so he loves it.
A short and simple poem published as part of Men and Women in 1855, "My Star" is impressive in its concise contemplation of love's singularity. It puts forth the idea that love is an intensely subjective experience that is appreciated differently by each person.
It is more than likely that Men and Women, Browning's first collection in years after marrying Elizabeth Barrett Browning, is meant to comment on their relationship. To whatever extent that might have inspired it, the poem is undoubtedly a love poem, the message of which suggests that the beauty any person might hold for another is entirely in the eye of the beholder, and that to love is to lose interest in how the beloved is viewed objectively. The speaker does not care that his star is viewed with indifference by his peers, but rather takes the occasion to admit for the first time his "love," a much greater feeling than the enthusiasm suggested by the first stanza.
In fact, the single use of the word "love" in the very last line is one of several factors that suggest the poem's primary theme is not love, but the nature of subjectivity. The first stanza captures the speaker's excitement in its short quick lines, whereas the second stanza, with its longer, more traditionally structured lines, affects a type of objectivity. From the objective standpoint, the star is nothing special, especially next to the planet Saturn. However, even in the midst of expressing himself objectively, the speaker takes a moment to insist he continues to pine for his star. The poem suggests more than just that love is in the eye of the beholder, but by extension, that everything perceivable is equally subject to untranslatable personal experience.