Space.com is carrying news that scientists still have a long way to go understanding what makes stars tick:

A star 40 times the mass of the Sun collapsed to form a neutron star instead of a black hole, researchers said today.

When a massive star burns out, its outer layers crash down on the star’s core, creating a dense ball of matter from which nothing could escape. Scientists previously thought that when a massive star died and collapsed on itself, it had no choice but to create a black hole.

Now, new data from NASA’s Chandra X-ray Observatory suggests that massive stars have a little wiggle room, and sometime produces a neutron star instead.

The thought of something 40 times as massive as our sun having "wiggle room" to do anything is a bit hard to get my head around. I'll take their word for it.