The Bhagola, or 'starry sphere' is the term used to refer to the idea that the asterisms of stars, (nakṣatras and rasis), all orbited the Earth at roughly an equal distance. It was part of the geocentric model of the solar system of early Indian astronomers.
Lalla describes it in his writings on the physical model of the universe known as the armillary sphere. The Bhagola is placed inside of the Khagola (Celestial sphere), the latter being perhaps stationary and mounted on four pillars. The Bhagola is then rotated by ropes &c.