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Science Forum

Science Forum

  1. Standard member sonhouse
    Fast and Curious
    20 Oct '17 13:18 / 1 edit
    https://www.washingtonian.com/2017/10/20/american-university-professor-student-played-part-biggest-scientific-discovery-2017/

    The latest from LIGO, 2 neutron stars spiraling in and merging.

    The question is, how close are those neutron stars from making a black hole? If the mass V radius to make a black hole is X and you have two neutron stars at 0.5X would they become a black hole when they merge?

    Another take on this latest detection: Proving Einstein was correct:

    https://www.eurekalert.org/pub_releases/2017-10/uoj-han101817.php
  2. Standard member DeepThought
    Losing the Thread
    21 Oct '17 04:56
    Neutron stars have masses between 1.3 and 3 solar masses. Above 3 solar masses they are believed to be unstable against gravitational collapse to a black hole. So the combined masses of two midrange neutron stars is enough to produce a black hole, but such a collision is likely to be a highly energetic event. One would expect significant amounts of material to be ejected, so without detailed knowledge of the dynamics of neutron star collisions your guess is as good as mine. At a guess, if both neutron stars have masses over about 2.5 solar masses, the merged object will be a black hole.
  3. 22 Oct '17 02:01
    do all neutron stars become black holes?
  4. Standard member sonhouse
    Fast and Curious
    22 Oct '17 03:44
    Originally posted by @lemondrop
    do all neutron stars become black holes?
    No, not many at all. They are an intermediate state in terms of the mass of the progenitor star, like he said, if the star masses around 3 times our star mass (2E30 Kg times three, or 6E30 Kg) then it can become a black hole but stars below that mass will more likely become a neutron star or red dwarf when they go nova.
  5. Standard member DeepThought
    Losing the Thread
    22 Oct '17 10:55 / 2 edits
    Originally posted by @sonhouse
    No, not many at all. They are an intermediate state in terms of the mass of the progenitor star, like he said, if the star masses around 3 times our star mass (2E30 Kg times three, or 6E30 Kg) then it can become a black hole but stars below that mass will more likely become a neutron star or red dwarf when they go nova.
    The progenitor star has to have a mass over 8 solar masses for the remnant to become a neutron star. The core of the star collapses, the rest of the star is blown off during the collapse. The remnant has a mass less than 3 solar masses or is a black hole. For a black hole the prosecutor star has to have a mass of at least of the order of 20 solar masses.

    If the remnant is heavier than about three solar masses, then, as I understand it, the collapse to a black hole happens more-or-less immediately.