Aurora Borealis

[Revan]

Can the Aurora Borealis created by a Starsoul sorcerer be created in a circle? The ability reads:

"Aurora Borealis (Sp): At 9th level, you can create a sheet of cascading colors. This power acts as a wall of fire, but it inflicts cold damage and does not radiate heat. However, one side of the aurora designated by you fascinates creatures within 10 feet, up to a maximum of 2 HD of creatures per sorcerer level. A Will save negates this fascinate effect. The save DC is equal to 10 + 1/2 your sorcerer level + your Charisma modifier. You may use this ability for a number of rounds per day equal to your sorcerer level. These rounds do not need to be consecutive."

Is 'sheet' to be taken as flavor text, or as a specific rule overriding the fact that it otherwise functions as Wall of Fire, which can be made circular?

[Morridir]

I believe a sheet doesn't necessarily have to be flat. Just as a sheet of paper can be bent, so can the Aurora Borealis. If you want, you can bend it in a circle. I think it refers to the Aurora Borealis looking like the real-life northern lights, which are 'sheetlike' as in: long but thin.

[DesolateHarmony]

Wall of Fire

It acts as Wall of Fire, and Wall of Fire can make a sheet or a ring. The word 'sheet' in the first sentence of the Aurora description might restrict it to only the sheet form. *sigh*

[Morridir]

Maybe I didn't clarify what I meant: I believe the sheet not to refer to the sheet as described within the wall of fire text description, but to the semantic definition, "a portion of something that is thin in comparison to its length and breadth", as given by the Merriam-Webster dictionary.
If the specific rule would have been that it can only be in sheet form as in the wall of fire "sheet", I would assume this to be mentioned after the "wall of fire" part where they added the specific rules, such as "inflicts cold damage", "does not radiate heat".