The Sunshot is an Exotic Secondary Weapon in Destiny 2.
It’s rewarded automatically for the main mission “Riptide” on Titan moon. After the mission you must speak with Sloane and can pick one of three exotics.
Exotic Name: Sunshot
Type: Hand Cannon (Secondary)
Required Level: 11
Item Description: “Can’t outrun the sunrise” – Liu Feng
Special Ability #1: Sunburn — Explosive rounds. Highlights targets.
Special Ability #2: Targets killed with Sunshot explode in Solar energy.
Acquired by: Beat the ‘Sacrilege’ main mission on IO and you can pick it as a quest reward from Fragment Researcher Ashermir.