The asteroid 2063 Bacchus because IIRC Bacchus (Dionysus)'s tales have some themes of gender non-conformity. But in a more serious tone, the Hellenistic mythologies used to have some gender non-binary figures such as the statues of Aphroditus, but the Latin-speaking Italian Romans generally took gender roles very seriously even before Christianisation, so you’ll probably have to find some non-Latin astronomical object.

Saturn because it has a ring and that’s cool

the symbols for sun ☉ and earth 🜨 are pretty neat for that i think!

As the planets were named after Roman deities created specifically to shoehorn celestial objects into binary gender roles, I don’t think the Roman pantheon would be a good model for non-binary identities.

And then they had to go a step further reduce gender roles into being represented by just those two gods. It’s like we’re going backwards.

The earth since it’s between Venus and Mars

Alpha Centauri maybe?

Thought to be a single star by the Greeks, but are a collection of many different stars in reality.

LV-426 or G-435 for aces definitely.

Fr though maybe Saturn.