The Green Sun is a giant sun in the middle of the Furthest Ring, nearly twice as massive as Earth's universe (and in fact, as massive as Earth and Alternia's universes put together) There is only one in existence, and it is the source of the powers of all first guardians. The pre-scratch kids and post-scratch trolls intended to destroy the Green Sun so that Jack Noir would lose his power. According to Doc Scratch, the destruction of the Green Sun would result in the destruction of the first guardians.
It was created after Dave and Rose detonated The Tumor in Paradox Space, destroying both Earth and Alternia's universes to fuel it - having been led to believe (by Doc Scratch) that this would destroy the Sun, not make it. In actuality, Doc Scratch never said it would destroy the sun, only that it had the potential power to do so. Rose simply did not ask him the right questions.
However, Jade says that the Green Sun presides over our universe, and that destroying it would have been disastrous. She also mentions that it presides over multiple universes and sessions at once, asking John to think of it like a giant solar system, but instead of planets revolving around the sun, there are many universes. This implies that Rose and Dave's mission, even though they were fooled into creating the Green Sun instead of destroying it, was still important, and can still have positive results for the future of our heroes.
It is referenced by carvings inside a turtle temple on the Land of Light and Rain. Rose, ignoring the advice of Kanaya, rips the temple out of the water and dismantles it with the Thorns of Oglogoth to find the Green Sun carving inside. A representation of the sun appears to be carved into the likeness of a giant captchalogue card.
An image of the Green Sun can be seen briefly flashing when Bec uses his powers; its first appearance was during , which was also Bec's first appearance. However, the only other known first guardians, Doc Scratch and God Cat, never display this visual effect while using their powers. It may be that the appearance of this power varies for different first guardians.
It is also seen when Jack Noir attacks Aradia, at which point she slips through him into the Furthest Ring, the Green Sun right in front of her. She then ends up at the Green Sun, but then leaves it to explore dream bubbles.
At the end of Jade's, a stylized green sun is shown woven into her bedsheets. This is because Becsprite made a sprite power copy of her bed to catch her, turning her sheets green and white.
In the opening sequence of Seer: Descend, a picture of the Green Sun flashes amidst a barrage of other images; it is quickly followed by a second picture of a pink sun, that might correlate to a sun we have not yet seen, but has been hinted at with the dual moons of Alternia. It might be present in the animation simply for aesthetic reasons, though.
It is destroyed during Act 7 by Alternate Calliope. The full ramifications of this event are not fully explored.
Similar Objects in Other Works of FictionEdit
The House on the Borderland also features a Green Sun twice the mass of the Universe. "And then, suddenly, an extraordinary question rose in my mind, whether this stupendous globe of green fire might not be the vast Central Sun--the great sun, round which our universe and countless others revolve. '..."
In the game Exalted, the Sun of Creation was once green, its light so pure it could not cast any shadows. The presiding Primordial was tricked into creating The Unconquered Sun (the normal Yellow-Gold Sun) afterwards. Ligier, the Green Sun, remains the heart and most visible sub-soul of the Demon City Malfeas. In the book Shards of the Exalted Dream, one of the variant settings gave one of Ligier's manifestations a mass twice that of the universe.