Originally Posted by
Crake
I know it was discussed and likely rejected on the first page, but opening a gate in the middle of the sun would do it, and you can take out a plane of your preference in the process! The intense gravity of the sun would cause an immense amount of super-dense material to flow through the gate for its short duration, and while it won't be enough to wink out the sun, it will probably be more than enough to reduce the sun's mass by enough to trigger a supernova.
For those confused, the sun's huge mass is keeping its own explosive force from doing just that, exploding. If you can take out enough of its mass, especially from its superdense core, you'll reduce its gravity enough that it will just simply explode as its explosive force becomes greater than its implosive force.