You know, I could be mistaken, but didn't GR talk about Vulcan having more than one sun? I'm not sure what to make of that, other than possibly alluding to STAR WARS and that's if it's even in there ...
Many star systems are binary or multiple, and many, many works of science fiction
featured planets with multiple suns long before Star Wars
came along (most famously in Asimov's "Nightfall," about a world with six suns). The problem with assuming that a given trope is a reference to Star Wars
is that absolutely everything in Star Wars
is itself an homage or pastiche of something from an earlier work. (But then, so is almost everything in Star Trek
. Neither Roddenberry nor Lucas was an innovator so much as a distiller and popularizer of pre-existing genre tropes.)
It was in 1968 that James Blish first proposed 40 Eridani as Vulcan's home system in his adaptation of "Tomorrow is Yesterday." 40 Eridani
is a system with three stars. However, I can't find a reference in the TMP novelization to Vulcan having more than one sun. The chapter set on Vulcan makes two references to the "red dawn," but that's as close as it comes to mentioning a sun or suns.