Star Trek: 10 Ways The Romulan Supernova Impacted The Multiverse
1. 'Two Form'-erly Known As Vulcan
There has never been an official number given for the population of Romulus, and after 2387, there wasn't one to give. Star Trek: Star Charts offers a hypothetical "18 billion" (around 2379), but that's not canon per se. Either way, "900 million" seems awfully low, but then that was likely 'just' the number of Romulan citizens the Federation had to relocate. "Billions" in the Beta Quadrant were in the "burst radius" according to Raffi in The End Is the Beginning, and that's not to mention the frankly baffling 'galactic' threat the supernova was said to pose in Star Trek (2009). How many Romulans died? We don’t know.
What we do know with greater precision is the number of Vulcan lives nixed through a black hole by Nero in the Narada in the alternate 2258 — almost 6 billion. "I am now a member of an endangered species," noted Kelvin Spock. With the no more than 10,000 Vulcans that remained, Spock Prime would go on to found 'New Vulcan,' later capital of the 'Confederacy of Surak,' ending his days on the planet in 2263.
Back in Prime, we know that the Romulans as a species survived into the 32nd century, having achieved Spock's dream of reunification in one of the centuries prior. Vulcans and Romulans now shared a home on 'Ni'Var' (previously Vulcan), a term that first appeared in issue one of the Star Trek fanzine Spockanalia in 1967, meaning 'two form'. If reunification were possible in Kelvin, it would no doubt have to begin the other way round. And with all the extra time, let's hope the galaxy was better prepared for the Romulan supernova if it also happened over there!