aestheticsymbols
Use in a combo

Comet copy & paste

☄ is comet, a plain-text Unicode symbol from the Miscellaneous Symbols block. On Aesthetic Symbols it lives in the stars & celestial collection, tagged star. As plain text it takes on the font and colour of wherever you paste it — a bio, a username, a caption or a stream title.

Unicode
U+2604
HTML entity
☄
CSS content
\2604
JavaScript
\u{2604}
UTF-8 bytes
E2 98 84
Made of

U+2604 ☄ · Miscellaneous Symbols

Will it show up? · Long-established text symbols

Plain-text characters from blocks that mainstream desktop and mobile fonts have covered for years. These are the safe ones.

Worked out from how each character is encoded, not from a test on a real device.