When I read about the fireball, I pictured the first stage of Gradius II or the fire level of Life Force/Salamander.
Which would explain why the Vic Viper would chart such a dangerous route to the enemy's lair: the firey mass is 5 billion times the size of Earth's solar system, so there was no going around.
The diameter of this fireball of gas is 3 million light-years with a tail of another 3 million, while the size of known large galaxies (like our Galaxy) is about 100.000 light-years long and 3000 thick, but, considering mass, the ball has about 1 billion times the mass of the Sun, while the masses of known galaxies range from 0,25 to 2.080 billion times the mass of the Sun, with most of them around 10 billion.
So this huge fireball is larger than a Galaxy!
I wonder what would happen if it met a black hole?!