Talk about a long trip. An exploding star‘s burst of light traveled 13 billion years, from the early days of the universe to the present day, before being detected by astronomers here on Earth. Researchers say this exploding star is the most distant blast ever seen.
The light from the distant explosion, called a gamma-ray burst, first reached Earth on April 23 and was detected by NASA’s Swift satellite. Gamma-ray bursts are thought to be associated with the formation of star-sized black holes as massive stars collapse. Within hours, telescopes around the world were turned on the burst — the most violent explosions in the universe — observing its fading afterglow to glean clues about its source and location [SPACE.com].
As explained in two papers in Nature, the astronomers determined that the explosion happened just 630 million years after the Big Bang during a period of time known as the cosmic dark ages. In that era of primal darkness, the first generation of stars were born. The earliest stars are thought to have been massive, short-lived balls of hydrogen and helium, whereas their offspring incorporated heavier elements formed in the first generation’s explosive demise [Scientific American]. Because the recently viewed blast resembles more recent gamma ray bursts, researchers say the star was probably part of the second or third generations of stars.
Says study coauthor Dale Frail: “The primal cosmic darkness was being pierced by the light of the first stars and the first galaxies were beginning to form. The star that exploded in this event was a member of one of these earliest generations of stars” [SPACE.com]. Researchers plan to train the Hubble Space Telescope on the ancient galaxy where the star exploded in an attempt to learn more about the universe’s first stars.
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Image: NASA/Swift/Stefan Immler
October 28th, 2009 at 7:01 pm
oh come one…that was so easy and yet you missed it… “talk about a blast from the past…”
sigh
October 28th, 2009 at 9:22 pm
Despite of my name I am not an astro-anything ;)
My noob question is this: If the universe when only 0.7 billion years old (in this case) and were packed much much denser than present, why would it take 13B years for the light from the GRB explosion to reach us? Is/was the rate of inflation magnitude faster than E=MC^2 which is not supposed to be possible, right? Is it because the source of the GRB and the Earth are at the edge of this inflating “balloon”?
OK, wise guys. I can spend a day in Wikipedia reading about the Universe’s Inflation Theory, etc, etc. I just want to ask some really wise people here that are astro-somethings. :p
October 28th, 2009 at 10:35 pm
Space does not have to expand at the speed of light in order for this phenomenon to exist. If you have two points, all of the space between these two points still expands. This can have the effect of increasing the total distance between the two objects at a rate greater than the speed of light. This is not the case here (the light just ends up extremely red-shifted).
Anyway, your question contains a supposition; that space itself cannot move at the speed of light. I think that is the ultimate endgame of the universe. However, when when space does expand at this rate, none of the force carriers from any particle will be able to reach another particle: no gravity, no light, no atoms, just lonely particles.
October 30th, 2009 at 12:18 pm
If the expansion of the universe is accelerating then why would the light catch us now?