Does a singularity appear the instant a black hole is formed? [duplicate]

Imagine a very heavy (tens of solar masses) star in its final moments before collapsing to form a black hole. The gravitational force exerted by the weight of the star overcomes the neutron degeneracy pressure and the star continues to collapse inward until the escape velocity at some radius from the star exceeds the speed of light. Now pause at the exact moment this happens.

Am I correct in thinking that at this point we have a black hole, since there is a radius at which light could not escape? If the answer is yes, then from what I understand this black hole must have a singularity. Assuming that a singularity can only exist behind an event horizon, this singularity must have come into existence at this exact moment.

My question is twofold:

• Are all of the above assumptions / assertions correct?
• How does a singularity instantly form?

Apologies if the question is naive - I am just a curious innocent rather than an expert!

marked as duplicate by John Rennie black-holes StackExchange.ready(function() { if (StackExchange.options.isMobile) return; $('.dupe-hammer-message-hover:not(.hover-bound)').each(function() { var$hover = $(this).addClass('hover-bound'),$msg = $hover.siblings('.dupe-hammer-message');$hover.hover( function() { $hover.showInfoMessage('', { messageElement:$msg.clone().show(), transient: false, position: { my: 'bottom left', at: 'top center', offsetTop: -7 }, dismissable: false, relativeToBody: true }); }, function() { StackExchange.helpers.removeMessages(); } ); }); }); Apr 12 '16 at 9:41

• Possible duplicate of: When does a singularity start to exist during a black hole formation? – John Rennie Apr 11 '16 at 17:27
• Not really relevant to your question, but neutron degeneracy pressure is certainly not the thing that has to be overcome in order to form a black hole. The equation of state of dense hadronic matter is much harder than that. – Rob Jeffries Apr 11 '16 at 21:25
• Thanks for that, I'll look into it. Am I still correct in assuming neutron degeneracy pressure is responsible for keeping a neutron star as a neutron star? – acernine Apr 12 '16 at 12:12