Hobus
From Memory Alpha, the free Star Trek reference
Hobus was a star in close proximity to Romulus and Remus. In 2387, after going supernova, destroying Romulus.
Ambassador Spock took the Jellyfish with red matter on board in an attempt to use the red matter to stop the star from going supernova. Spock failed at his original goal, but he did use the red matter to prevent further damage, and, in doing so, created an artificial black hole that pulled in both Nero and Spock, sending them back to 2233 and 2258, respectively, and creating an alternate reality. (Star Trek)
[edit] Apocrypha
In Star Trek Online, a scandal occurs several years later. It involves rumors that the Vulcan Science Academy knew about the instability of the star but did nothing until Spock attempted to save Romulus with the Jellyfish. The scandal results in several resignations and sows seeds of distrust towards the Vulcans.
