"Middleweight" Black Holes...

Discussion in 'Astronomy, Exobiology, & Cosmology' started by TruthSeeker, Apr 16, 2004.

  1. TruthSeeker Fancy Virtual Reality Monkey Valued Senior Member

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    I just found this: "Runaway star collisions create black holes"

    "In computer-simulated stellar clusters, two stars each weighing more than a hundred Suns come together, creating a superstar whose increased size and gravity make it a target for more impacts. In just a few million years -- a cosmic blink of the eye -- a ball of gas equal in mass to a thousand regular stars snowballs into existence."

    Huh... am I dumb or there are no stars more massive then 100 solar masses?

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    An 100M<sub>o</sub> star would have an incredibly fast life. The equation, if I remember well is T=10Gyrs X 1/M<sup>3</sup>. In the case of an 100M<sub>o</sub> star, it would live for about 0.00001Gyrs. The chances of it colliding with other star as massive (or even with any other star!) would be very slim. Also, massive stars are never found in globular clusters... or stellar clusters, whatever that is. :bugeye:

    Anyone understands anything about that?

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  3. Pete It's not rocket surgery Moderator

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    Here's the abstract of the Nature article. The context is a very young star cluster in a galaxy with high star formation (starburst galaxy).

    And even better, here's a complete article of the same research published in Astrophysics in February:
    The formation of massive black holes through collision runaway in dense young star clusters (Abstract, links to full text pdf, postscript, and other)
     
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  5. TruthSeeker Fancy Virtual Reality Monkey Valued Senior Member

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    Weird...

    But I might be right. The link that you provided and the abstract of the Nature article don't say anything about stars of hundreds of solar mass as the link that I posted. Maybe there are many stars colliding, wheter then a few with more then 100 solar masses...?

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  7. Pete It's not rocket surgery Moderator

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    It's there if you read it carefully. The simulation started with stellar masses around 100, and built through collision to perhaps 3000 M<sub>0</sub>1

    Also check this link: Biggest Brightest Star Puzzles Astronomers
    (150 solar mass star, expected life 2 million yr)
     
  8. TruthSeeker Fancy Virtual Reality Monkey Valued Senior Member

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    That's scary...

    What is the kind of star? Wolf-Rayet (or something like that)?

    "Light from LBV 1806-20 undergoes periodic variations that seem specific to a one-body object, Eikenberry said. If it is eventually found to be a binary or triple-star system, it would be even more confusing, since astronomers would have to explain how these massive stars manage to exist so close together, he said. "
    Roche Limit? Similar to Blue Stragglers? Why not? Even seems like an explanation to such a massive star(s). And that would make them last much longer too...

    "One possible answer to the mystery of LBV 1806-20’s continued existence could be the neighborhood beyond the star's immediate surroundings. The star resides in a cluster populated by extremely rare star or unusual stars, including a intensely powerful magnetic neutron star and a massive protostar, one yet to be born. "
    Weird! :bugeye: Where is that star located? Which constellation? How far away is it? Oh... never mind...

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    "Stars like LBV 1806-20, which Eikenberry estimates is only middle-aged at about one million years old, can shed huge amounts of material in a wind similar to solar wind of the Sun. He said the huge star could end in a hypernova explosion with a powerful burst of gamma rays."
    Here we go again...

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    It IS a Wolf-Rayet, eh?
     

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