JMS discusses Kolob, says it is a "sun" and a "world."
Janne M. Sjodahl, "The Word 'Kolob'," Improvement Era 6, no. 16 (April 1913): 620
According to the Book of Abraham, a translation of which was given to the world by the Prophet Joseph Smith, the system of worlds to which our globe and the nearest orbs belong is "governed" by a great central sun, first in the order of creation and located near the throne of God. This great world, the Book of Abraham informs us, rotates around its axis in a period of time equal to a thousand of our years, and this is "a day" according to the celestial measurement of time.