Have the possibility to destroy a star

By destroying a star, it destroy all around.

For example if a war begins and the ennemy is too strong I can choose to sacrifice some of my planets. By destroying the star I destroy all the planets around and the ennemy if he is near enough.

Condition : I must have colonised all the planets of the star's system.
This way I can slow down the ennemy but in an other way I have to consider it well, because I can loose a lot.

Sorry for bad english, I'm not sure if it's well written ^^