Science Buddies: "Ask an Expert"

I've been doing some research on Wolf Rayet stars but I'm finding hardly any information on how exactly they evolve.

Do all Wolf Rayet stars collapse into black holes due to their large masses? And what type of supernova do these stars most commonly explode as?

I will have to start this by saying that I am not an astronomer so take anything I say with healthy skepticism. I have looked at some of the literature out there. The University of Pittsburg has an interesting article on W-R stars:
http://kookaburra.phyast.pitt.edu/hilli ... _paper.pdf

There are all sorts of theories in astronomy but the field is evolving all of the time. To be honest with you nobody knows the answer to this. While String Theory and other groups have predictions on Black Holes and W-R stars nobody has been able to prove that these stars CAN go to a black hole state. Nobody out there can really explain what a black hole is let alone how they are formed. I cannot find any instance where any astronomer has actually observed a W-R start turning into a black hole. All of the conjecture on these stars is based on theories as to what should occur next not on observation. Everyone has a theory about it that fits the particular mathematical models that they use, but they are unproven which is why they are theories. Also it is a mistake to assume that anything in the Universe ALWAYS does any one thing. The universe doesn't always conform to our expectations.

Hi VCaballero,

I wanted to add a few things to prbeck's response. Wolf-Rayet stars are massive and, based on observations and theory, will end up as a neutron star or a black hole after going supernova, depending on mass. Astronomers actually have witnessed a W-R star exploding. In 2014 astronomers observed a Wolf-Rayet star only a few hours after the star went into a supernova phase (type IIb). The article was published in the prestigious journal Nature. I don't think you will be able to access the article itself, but this popular article describes the key findings:

http://www.iflscience.com/space/astrono ... y-explodes

Finally, please note that while astronomy is a rapidly evolving field, theory and observations are tightly linked. Scientists also use the word "theory" in a different way than most people do. Check out this article that explains what a scientific theory is (and is not):

http://undsci.berkeley.edu/article/howscienceworks_19