A supernova ('nova' meaning new in Latin) is a massive explosion which occurs during the last stages of a giant star's life when it exhausts its supply of fusable hydrogen, collapses and expels its outer layers into space, leaving behind a bright 'new' star which slowly fades away.
The Supernova is a type of satellite drop weapon which is placed in a standby orbit around the Earth and when needed, changes its orbit to drop down to Earth and bomb an enemy nation. It is equipped with a thermobaric warhead capable of wiping out anything within a 1.2km radius and is designed for stealth, with its boosters not providing much of a heat source. The Supernova has a number of strategies for countering attempts to shoot it down, like from an Object's anti-air lasers, such as scattering chaff or flares to break targeting looks, firing its boosters at random to move around like a living creature, and hiding behind another Supernova to use it as a shield.
In August, the Supernovas were hijacked, activated and set to fall on Second Venice, moored at Malta. The Baby Magnum was tasked with shooting the weapons down, with the Gatling 033 supporting. The weapons were intercepted, however the Appetizer Asteroid fell at the same time and caused major damage to Second Venice, allowing Kerukeion to seize the control of the island's infection base.