I messed around with Processing some more (actually, a while ago, but whatever) and these are the results. This symbol has a few different meanings throughout my Legacy universe (under construction). Within the universe's fictional history, it's been passed down from civilisation to civilisation, symbolising different things to each.
Symbol of the Seedworld Network
The Nullartus species, also called the Limbless, see themselves reflected in this symbol; it has their torso and five (floating, because magic) body parts - head, hands, and feet.
Flag of the United Nullartus Republic
Republic of Vanguard
After the United Nullartus Republic shattered in civil war, a group of refugees made its way across the ocean and landed on another continent to the southeast. They became the city-state of Vanguard.
Flag of the Second Mighty Empire of the Limbless
The successor state of the United Nullartus Republic emerging from the end of the civil war, the Second Empire had slightly more, ah, supremacist tendencies.
Flag of Remnant
After a calamity strikes the Nullartus species, only a few hundred are left; most reside in the village of Remnant.
First Legion of the Nullartus
The ones without circle backgrounds look kind of weird, like they're not quite centred; in fact the middle circle is centred, but the top circle is closer to the top edge than the bottom two circles, because that's how circles work. Not sure what to about that, honestly; the background circle helps, but I'm not sure I like it for all of them, and the word circle is starting to lose all meaning to me now.
Original starry image (The star formation region NGC 6559): By ESO (http://www.eso.org/public/images/eso1320a/) [CC BY 4.0 (https://creativecommons.org/licenses/by/4.0)], via Wikimedia Commons