About Sun Symbols
This page holds three different kinds of character that happen to look related. ☀ ☼ ☉ are astronomical text symbols. 🌞 🌤️ ⛅ 🌅 🌇 are emoji depicting the sun or the sky. And 🔆 🔅 are neither — they are interface icons for a brightness control. All ten copy the same way, but they do not mean the same kind of thing.
The Text Suns
☀ is the standard sun with rays, ☼ the white variant with a dot at the centre, and ☉ the astronomical sign for the Sun — a circle with a central dot, the same mark used in astronomy for the solar body itself.
All three are monochrome and take the colour of the text around them, which makes them the ones to use in a styled name. ☉ is the quietest of the three and works where ☀ would be too busy.
🔆 and 🔅 Are Not Suns
These two are the high-brightness and low-brightness symbols — the icons a device shows on its screen-brightness slider. They are a matched pair, and used as a pair they read as a dimmer control rather than as weather.
That does not make them unusable in a name; it does mean a reader who recognises them sees a settings icon. If you want the sun rather than the button, ☀ or 🌞 are the clearer choices.
Sky Scenes, Not Sun Symbols
🌅 and 🌇 are full scenes: a sunrise over water and a sunset behind buildings. At the size text renders in a bio, the detail in both collapses into a coloured smudge — they work far better in a post than in a username.
🌤️ and ⛅ belong to the weather set and are covered in more depth on the weather symbols page.