Goerge Reynolds discusses the astronomy of the BOA; describes Kolob as a "governing planet."
George Reynolds, "The Book of Abraham—Its Genuineness Established. Chap. VIII," The Latter-day Saints' Millennial Star 41, no. 8 (February 24, 1879): 115
The great truths told by Abraham regarding the starry hosts of heaven are recorded thus: “I saw the stars that they were very great, and that one of them was nearest unto the throne of God; and there were many great ones that were near it; and the Lord said unto me, These are the governing ones; and the name of the great one is Kolob, because it is near unto me, for I am the Lord thy God; I have set this one to govern all those which belong to the same order of that upon which thou standest, And the Lord said unto me, by the Urim and Thummim, that Kolob was after the manner of the Lord, according to its times and seasons in the revolution thereof, that one revolution was a day unto the Lord, after his manner of reckoning, it being one thousand years according to the time appointed unto that whereon thou standest. This is the reckoning of the Lord’s time, according to the reckoning of Kolob.”
In other words, these great governing planets control all others in their revolutions, or are the centres around which the others revolve. As the moon revolves around the earth, and the earth with the other primary and secondary planets belonging to this solar system revolve round the sun, so has the sun a centre around which it, with all its earths and moons, revolves, while this grand centre has a governing planet also, a sun or world around which it, with its attendant systems of suns and worlds, revolve, and so on until we come to Kolob, the "nearest to the celestial or residence of God," which is the grand centre which governs all the suns and systems of suns "which belong to the same order" as our earth, and those that move with it.