Supernova made his debut in the pages of 52. As the world struggled to cope with the death of Superboy, the absence of Batman, Superman, and Wonder Woman, and public scandals involving the popular celebrity hero Booster Gold, Supernova appeared out of nowhere and quickly gained the trust of Metropolis.
With mysterious powers and the air of a weathered veteran, Supernova was professional and his performance in action was perfect. He even gained the approval of Daily Planet reporter Clark Kent.
The identity of Supernova was a mystery, but various characters had their own theories. Lex Luthor thought it was the missing Superman, taunting him with a new identity. Wonder Girl thought it was her recently deceased boyfriend Superboy, risen from the dead like Superman before him. Booster Gold didn't care who it was-- all he cared about was upstaging him. When a nuclear sub was damaged in Metropolis, Booster rushed to contain the blast to protect the city and upstage Supernova, apparently dying as the sub detonated high above the city. Supernova could only recover Booster's skeleton after the blast.
Skeets, Booster's best friend and sidekick, who had been acting strangely since the events of Infinite Crisis, was highly distraught by Booster's death. He tracked down Booster's ancestor, Daniel Carter, and convinced him to put on Booster's suit and investigate the HQ of Rip Hunter, which would only open for someone with similar biometrics to Booster. When Skeets discovered notes in which Rip had labeled him as the cause of everything gone wrong, he trapped Daniel in an endless time loop and began a rabid search through the time stream for Rip Hunter.
Eventually, it was discovered that Supernova was working for Rip Hunter. When Skeets cornered Hunter in an abandoned Fortress of Solitude near the Bottled City of Kandor, it was revealed that Supernova was actually Booster--who was still very much alive--using a Phantom Zone projector to simulate new powers. When he attempted to use the projector against the villainous Skeets, Skeets somehow ate the Phantom Zone.
Apparently, Rip had met with Booster in secret early on during the events of 52 and revealed the truth about Skeets's betrayal. Booster then went to the future, dug up his own corpse, pretended to lose control of himself and destroy the nuclear submarine, then planted his corpse on the scene and went back in time to pose under the guise of Supernova. Because Supernova and Booster where seen together and separately at the same instant, no one could suspect them to be one and the same, and their rivalry manufactured. This ruse allowed Booster to operate in secret against Skeets without suspicion.
Skeets in turn revealed the secret to his recent erratic behavior: he was infected by Mr. Mind, who was now fully grown, integrated with the Phantom Zone, and eager to eat all of the new The DC Multiverse.
During the fight to save everything, Supernova appeared once again to aid Booster. Rip revealed that he had found Daniel Carter lost in time and gave him the Supernova suit to increase their numbers. The three defeated Mr.Mind together, and the Multiverse was saved.
In the pages of the subsequent Booster Gold series, Daniel Carter was seen enjoying civilian life augmented with a super suit that allowed him to go without food or sleep so that he could focus his time on video games while Booster and Rip set off on another adventure to protect the multiverse. However, after they leave, Daniel is blind sided by a mysterious new stranger, later revealed to be Booster's father, Jonar Jon Carter, who stole the Supernova costume for his own nefarious purposes. Jonar was later seen teamed up with the Time Stealers in an attempt to take over the world by altering the past to prevent the world's greatest heroes from forming. Ultimately, he was stopped and he was revealed to be the host of Mr. Mind and his spawn. Booster was forced to tear his father's ear off to stop Mind. It is unknown if Jonar survived the encounter.
Supernova's design is based on a Pre-Crisis "Imaginary Story" in which Superman lost his powers. When the government tested a "super-cobalt bomb", it ripped a hole in reality. Superman opted to investigate it and was coated in some sort of anti-septic from machines. When he arrived back on Earth, doctors informed him that the anti-septic had drained his powers from him--making him an ordinary mortal.
Refusing to give up super heroics and inspired by such non-powered heroes as Batman and the Green Arrow, Superman donned a cape devised by Leonardo Da Vinci and took on the identity of Nova. The cape allowed him to glide on air currents, as well as hiding various gadgets inside of it, such as knockout gas. Unfortunately, while Nova was still an exemplary fighter, Clark was used to not using the full force of his strength, which led to him being knocked out by a group of gangsters working for Mr. Socrates. Socrates had the captive Superman programmed to obey his commands. Eventually, Superman and Batman were able to disable the chip in Superman's neck that allowed Socrates to control Superman, and Socrates was killed by a bomb meant for Batman. In the end, Superman mothballed the Nova costume. What happened to it afterwards is unknown.
During the events of Infinite Crisis, Nova was one of the many alternate Supermen shown when Alexander Luthor Jr split Superman into alternate reality versions.