Marvel Ultimate Graphic Novel Collection Issue 91 : Nova - Origin

Sam Alexander always believed that his father's half-remembered tales of intergalactic police and alien invaders were nothing but drunken ramblings. But when he discovers his dad's old Nova Corp helmet, Sam realises there may be more to his stories than meets the eye! Taking on his father's mantle as a Nova Centurion, Sam is thrust into a battle with the deadly Chitauri — an alien armada who stand ready to rain down ultimate destruction upon the Earth!

Collecting Nova (Vol. 5) #1–5, "Diamondhead" from Marvel Now! Point One.