How can the largest known star, VY Canis Majoris, have a mass about 40 times that of the sun and not implode?

As I understand it, gravitational collapse will always occur on any star over about 5 solar masses, inevitably producing a black hole. How can this red giant be 40 solar masses?How can the largest known star, VY Canis Majoris, have a mass about 40 times that of the sun and not implode?The (initial) mass of a star - to my knowledge - indeed determines whether or not the star will evolve into a black hole. Still that does not mean, that it should immediately do so. A very massive star will pass through various stages of existence - the red giant stage being one of those - before ultimately imploding.



Hence, the star you study should become a black hole, but first pass through several stages {described below}.



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As far as I know the following typically happens to a star of 20-50 solar masses:



1)It starts as a gas cloud - basically containing hydrogen - which compresses under the effect of gravitation, until it's Temperature rises high enough, so nuclear reactions can take place in its center. It is then said to enter the main sequence.



2)During that "main sequence" stage it will transform the hydrogen into helium and thus keep gravitative forces from making it collapse. but after some time all its Hydrogen will be gone. Gravitation will compress the star - since pressure is not stopping it anymore - until the temperature is so big, that other - previously impossible - reactions can take place. For instance Helium can be converted into Carbon.



3) These mighty reactions release such an amount of energy, that the star expands (and thus it's OUTER layers COOL). Cooler gas appears more red. The star now is gigantic and reddish. It is therefore termed a "RED GIANT". That is the stage in which - according to your sources - VY CM is nowadays observed. Our sun is expected to go through a similar phase. Probably it will then be so voluminous, that its outer borders will reach the earth!



Yet, even these reactions will some day stop, as all Helium will have turned into Carbon and the star will again be "squeezed" under the influence of gravity! If I am not mistaken during the latter stage stars loose a part of their mass, being stripped of their gaseous envelope. Still, for a star of 20 {or more} solar masses (NOT FOR OUR SUN, THOUGH) enough mass will be left for the process to start again. The core is compressed and when it gets immensely hot reactions even more powerful than those mentioned previously will take place. Those will expand the star, which thus becomes a "RED SUPERGIANT".



There are a few more phases the star could go through before becoming a black hole. For example, for that to be the case, gravity must first overcome the mighty forces which will {according to Pauli's principle} attempt to prevent the neutrons from being "pressed onto each other". Yet, for a star of the above mass, even that will occure.How can the largest known star, VY Canis Majoris, have a mass about 40 times that of the sun and not implode?Because the pressure from nuclear reactions is still enough to maintain a star. When the pressure subsides the star will implode and then explode in a supernova. After the final implosion it will be a black hole.