The statement about particle colliders is not really correct. The relativistic heavy ion collider, where I used to work, is about 2.4 miles in circumference, and reaches temperatures in the 10s of trillions of degrees in its collisions. This is > 1000 times hotter than a supernova. The environment in these collisions is made to reproduce the state of the universe fractions of a second after the Big Bang, and aren’t really comparable to any normal stellar activity.