The one you thought was the Nova symbol is actually the Guardians symbol. Note the starburst.
The ??? symbol is Doctor Strange.
haha wow, i didn't even know dr. strange had a logo. it's kinda awful for representing him without knowing the character but i guess it's hard to think of a good one for him too given the eye of agamotto is just a big ol eye
also that's real weird that the guardians symbol has the nova corps starburst in it.



edit:
wait fuck, that guardians logo is probably from the movie isn't it- that'd make sense if it was just something given to them by the nova corps in the movie
it's also used to represent kate bishop hawkeye, who doesn't have the mask. his old logo used to be the mask before the matt fraction run (i think?)EDIT: Wait that's hawkeye's? They couldn't just have the mask as the symbol?
the new logo is usually either the arrow or a bullseye which is kinda weird considering there's, yknow, a dude named bullseye who also has a bullseye as his logo