To begin figuring out Blake's use of the symbol 'stars' let's start with some of his geography.
Milton, Plate 13, (E 156)
"Around Golgonooza lies the land of death eternal; a Land
Of pain and misery and despair and ever brooding melancholy:
In all the Twenty-seven Heavens, numberd from Adam to Luther;
From the blue Mundane Shell, reaching to the Vegetative Earth.
The Vegetative Universe, opens like a flower from the Earths center:
In which is Eternity. It expands in Stars to the Mundane Shell
And there it meets Eternity again, both within and without,
And the abstract Voids between the Stars are the Satanic Wheels."
Damon (A Blake Dictionary) says of the stars in Blake: "They are the visible machinery of the astronomical universe," and "Albion's limbs once contained all the starry heavens."
Percival (William Blake's Circle of Destiny) explains :
"As Albion falls he carries his celestial light with him in ever diminishing strength and splendor. The heavenly light with which his world is illuminated is at all times, therefore, an indication of his spiritual condition. The eternal world of Eden and Beulah is lighted by the sun and moon in their diurnal courses. When that world fails and the Mundane Shell is created as a barrier against utter dissolution, light is provided by the stars which in their multiplicity represent the break-up of the eternal sun and in their unified westward movement represent the effort to maintain some vestige of eternal values. When the starry Mundane Shell crashes into the darkness of the abyss, the Planets, moving irregularly eastward, make their appearance. To counteract their maleficent influence Los creates a temporal sun and a temporal moon, feeble but indispensable replicas of their eternal counterparts.
The first diminution of light is indicated, as we have just said, by the star world. This world was created to keep the body of man from falling into the abyss, when both sun and moon had failed. When knowledge ceased to be intuitive and love ceased to be spontaneous, when in astrological imagery, the eternal order was threatened by the departure of Urizen, the sun, into the north (the realm sacred Urthona), and of Luvah, the moon, into the south (The realm sacred to Urizen), the diminished reason became Albion's guiding light. Out of fear it built the world of law that Albion might not descend into chaos. The ordered round of constellations is Blake's beautiful and appropriate symbol for the order imposed by law upon a world from which unity has fled." (page 148)
Marriage of Heaven and Hell, Plate 26, (E 44)
16. Falling, rushing, ruining! buried in the ruins, on Urthona's
17. All night beneath the ruins, then their sullen flames faded
emerge round the gloomy king,
18. With thunder and fire: leading his starry hosts thro' the
waste wilderness he promulgates his ten commands,
glancing his beamy eyelids over the deep in dark dismay,
America, Plate 8, (E 54)
The terror answerd: I am Orc, wreath'd round the accursed tree:
The times are ended; shadows pass the morning gins to break;
The fiery joy, that Urizen perverted to ten commands,
What night he led the starry hosts thro' the wide wilderness:
Milton, Plate 4, (E 98)
Every Mans Wisdom is peculiar to his own Individ[u]ality
O Satan my youngest born, art thou not Prince of the Starry Hosts
And of the Wheels of Heaven, to turn the Mills day & night?
Song of Los, Plate 5, (E 68)
Thus the terrible race of Los & Enitharmon gave
Laws & Religions to the sons of Har binding them more
And more to Earth: closing and restraining:
Till a Philosophy of Five Senses was complete
Urizen wept & gave it into the hands of Newton & Locke
Percival calls the stars the 'remnant of light left to the falling Albion'. From this remnant of light is built the Mundane Shell which embodies the law in 'beneficence and majesty'. So the trail left by the fall becomes the chain which restricts the fall. The voids between the stars are the 'doubt and negation of the spectrous mind'.
Percival calls to our minds that the appearance of the stars in the 12th of the Illustrations to the Book of Job 'marks Job's emergence out of the darkness of Ulro.