Article if you'd rather read about it.

A common joke is "just launch X into the sun and be done with it". Turns out, that's actually a really difficult thing to do.

From Earth, we would have to accelerate a spacecraft to 33 m/s in the opposite direction of our orbit in order to get it to fall into the sun (without entering an elliptical orbit) For reference, we only need to launch a spacecraft at 11 km/s in the same direction of our orbit to cause the spacecraft to escape our solar system.

This means that it would take less energy to launch a spacecraft to another star than our own sun.