The first four lines of “Bright Star” establish the poem’s form and its broad themes. The poem begins with the speaker addressing a “star” directly. This is an instance of apostrophe: the star is both very far away and not human.
In the first line of the poem, the speaker also expresses a wish to be as “stedfast” as the star. In other words, the simile suggests that the speaker wants to be as steady and as constant as the star. This wish is underlined by the assonance between “bright” and “I”: there is a sonic link that binds together the speaker and the star, and justifies the speaker’s desire to emulate the star. In making this wish, the speaker is playing on an old tradition in poetry. Since stars were used by sailors as fixed points to help their navigation, they were frequently symbols of stability and constancy.
But there’s a problem: the star is lonely. In lines 2-4, the speaker reflects on how isolated the star is from human life, how it hangs in the sky, watching events on earth. The speaker wants to be constant and steady like the star, but not isolated.
As the speaker describes the star’s isolation, he or she uses a series of devices. First, the speaker uses metaphor: giving the star “lids”—in other words, eyelids—and, implicitly, eyes, with which it watches events on earth. (The consonant /l/ sound in line 2 also reinforces the star’s isolation: linking together “lone,” “splendor,” and “aloft,” as if to insist that the star is only beautiful because it is so high above, so distant from, the speaker).
Then, in line four, the speaker compares the start to a “patient, sleepless Eremite.” An eremite is a hermit, someone who lives alone in the wilderness. Both the metaphor and the simile personify the star giving it human characteristics. (And once the star has received those human characteristics, it seems less weird to talk to the star, as the speaker is doing here.)
“Bright Star” is a Shakespearean sonnet and, in these lines, it follows the standard meter and rhyme scheme for this form: it’s written in iambic pentameter (five poetic feet per line, each with an unstressed-stressed syllable pattern) and rhymed ABAB.
The speaker generally handles this prestigious, difficult form with confidence—a confidence that reflects the strength of the speaker's conviction in the poem and the wishes it expresses. But there are some blemishes in the meter. For instance, note the spondee in the poem’s first foot: “Bright star.” This is followed by what is arguably a trochee two feet later: “would I | were sted-| fast as …” The speaker may want to be “stedfast” but the hiccups in the meter indicate that he or she isn’t quite there yet!