Nova (Sam Alexander) is a superhero appearing in American comic books published by Marvel Comics. The character, a space-faring member of the intergalactic police force known as the Nova Corps, was created in 2011 by writer Jeph Loeb and artist Ed McGuinness, based on the original Nova Richard Rider.

The Nova 6 gas in Call of Duty: Black Ops is a fictional chemical weapon, so there is no real-world equivalent or composition for it. The game's creators designed it as a deadly nerve agent with devastating effects. If you have any other questions about chemical compounds or fictional substances, feel free to ask!