Proton cannon

This caption is above 'Get off my lawn!' jokes, as are you.

Proton cannons are a type of weapon emplacement used to combat the threat of enemy starships.

Fiction

The Transformers cartoon

The Quintessons had a massive proton cannon that was used to defend Quintessa from invaders. The Aerialbots arrived on the Quintesson homeworld in order to rescue their fellow Autobots trapped on it which prompted the Allicon guards into firing their proton cannon at the Autobot Fleet. Whilst initially doing damage, Silverbolt sent Air Raid and Skydive to take out the cannon. Five Faces of Darkness, Part 2