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Mysterious Explosion Comes Out of Nowhere

Article written: 18 Dec , 2007
Updated: 26 Dec , 2015
by

When astronomers find a gamma ray burst, they can usually locate the culprit’s home galaxy. But in the case of an explosion that went off earlier this year, there’s no galaxy to be found – even with the most powerful telescopes on Earth.

The gamma ray burst GRB 070125 was first detected on January 26th, 2007 by NASA’s Swift telescope in the constellation Gemini. One of the brightest bursts of the year, astronomers scrambled to observe the explosion and then the slowly fading afterglow.

Gamma ray bursts occur when a massive star runs out of fuel. Without the light pressure, the star collapses inward on itself, turning into a black hole. This newly formed black hole spins at an enormous rate, generating enormous magnetic fields. These fields catch infalling material and spew it out again into powerful jets. And it’s those jets where the burst comes from.

One of the normal activities in observing GRBs is the identify the host galaxy so that astronomers can measure its distance. It’s also important to know what kind of galaxy the burst exploded within to better understand the kinds of environments can lead to these massive stars.

In the case of GRB 070125, though, no originating galaxy was obvious. Astronomers from Caltech/Penn State used the 60-inch Palomar Observatory to watch the afterglow, and then called in the even larger Gemini North and Keck 1 telescopes, located on Hawaii’s Mauna Kea.

Even with the power of Keck, they couldn’t find a galaxy.

So how could you get a gamma ray burst without a galaxy? Astronomers know that colliding galaxies can throw off enormous tidal tails that stretch away for hundreds of thousands of light-years. The original star could have been within one of these tidal tails, many light-years away from its parent galaxy.

If their theory is correct, a long duration exposure from the Hubble Space Telescope should reveal the dim tidal tail.

Original Source: NASA News Release


15 Responses

  1. Peter Brouwer says

    It is very likely to be a halo or trail of stars from an interaction. Do a couple of 1000 galaxies from galaxyzoo and you’ll quickly see how many mergers and interacting tidal galaxies there really are.

  2. Alfonso says

    How bout a rouge star? Could it have been a massive star that was ejected from a cluster or like Peter says from a merger?

  3. k. Ayal says

    NO!
    I think that the invizible dark mater exists only in atomic and molecular form

  4. Invisible Girl 0 says

    Do you think invisible “dark matter” could make some sort of a black hole? Or possibly a gamma ray burst that seems to have no origin?

  5. maybe the parent galaxy’s red shift is greater then ‘C’ – I expect they do exist and that the universe is bigger than just what we can see and maybe this star was ejected in our direction, taking it below ‘C’.

  6. Dirk says

    Or it is just a big plasma phase change from dark mode to normal glow mode: first you see nothing and suddenly there is a full spectrum of radiation.

  7. Amateur Astronomer says

    Let’s stay with Hakim’s Razor. It could be that a collapsing star formed a black hole which would explain the gamma ray burst. Could the GRB have been so great that it would leave the host galaxy undetectable?

  8. Usage Nazi says

    It’s ‘Occam’s Razor’. Although Hakim is a nice name. ;P

  9. Amateur Astronomer says

    Sorry, I do know this. I was dictating at the time.

  10. Va. Gent says

    Maybe, just maybe, it was a lone star thrown out from ag galaxy eons ago.Naturally after doing its thing you would get the G.R.B but no galaxy of course.

  11. Wadoino says

    But, a rogue still requires fuel to burst.

  12. Justin Mitcham says

    Maybe it’s aliens signaling us with the one thing that can be easily detected across the entire cosmos..LOL sorry been watching too much ST!

  13. Titan says

    This could be the death cry of a primordial black hole.

  14. shepard says

    This is a Question thats not part of the article.
    Does anybody else think that were not the only Intelligent life beings in the WHOLE* Universe?

  15. Chuck Lam says

    The probability that we are the only intelligent life form in the universe is insanely unlikely. Why then no alien contact one might ask? Simple!. The communication distances involved are entirely too vast. Communication modulated RF signal strength, for example, diminishes as the square of distance traveled. At, say, a million light years, which is cosmologically nothing, a million watt transmitter signal is reduced to a currently undectable fraction of a watt. Will contact with another intelligence eventually be made? Maybe and maybe not. Considering the youthful age of the solar system and human development against the age of the universe, I suspect dozens of intelligent life forms have come and gone and still exist in the universe. I believe it arrogant to think we are the only intellegence in existence. The probability of life numbers are too great for the human species to be alone.

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