Rare observation of cosmic explosion

Mar 10, 2011
Image from the Hubble Space Telescope, where you see the Gamma Ray Burst and the supernova as a bright point in the irregular galaxy located approximately 820 million light years from the Earth.

Gamma ray bursts, which are the most powerful bursts of radiation in the universe, have now been observed in direct connection with an exploding giant star - a supernova. Researchers from the Niels Bohr Institute at the University of Copenhagen are among those who have studied the rare event. The results have been published in the scientific journal, Monthly Notices of the Royal Astronomical Society.

"That we have observed a gamma ray burst and a supernova simultaneously is unusual and it gives us a long awaited confirmation of the theory that gamma ray bursts are indeed associated with exploding giant stars", explains Johan Fynbo, astrophysicist at the Dark Cosmology Center, Niels Bohr Institute at the University of Copenhagen.

An international team of researchers made the discovery using NASA's Swift satellite, which was first used to find the exploding star in the universe.

Seen here is a little section of the X-shooter spectrum. The figure illustrates how astronomers calculate the distance from the spectrum. By measuring how much certain features in the spectrum are shifted towards the red wavelengths, the so-called redshift can be determined. Thus, the distance is given based on the redshift, if you know the correct Big Bang model, and they believe they do.

They then observed the phenomenon from the European Very Large Telescopes, VLT in Chile, where using the special X-shooter instrument they could observe the object's light spectrum all the way from the ultraviolet to near the infrared at the same time.

Star explosion in the near universe

By analysing the light spectra and measuring the so-called redshift the researchers could calculate the distance to the supernova, which was located in a galaxy 820 million light years from the Earth. It sounds extremely far away, but for astronomers it actually a relatively near galaxy and that is a true delight.

"Only about one out of 10,000 supernovae produce gamma ray bursts. So gamma ray bursts are rare and gamma ray bursts in the relatively near universe are even more rare, so it gives us a unique opportunity to study the phenomena in detail. When you have one that is so near, it is like a clock telling you that the star is dying just NOW, and you can follow the early phases and the entire development of the that follows", explains Johan Fynbo.

It is only the very large, massive stars of more than 30-40 solar masses that produce gamma ray bursts. What happens is that when the star dies, it collapses and forms a black hole. If the black hole spins very quickly, a jet might appear - a , which is powerful, high-energy radiation, which shoots out at nearly the speed of light. It happens very quickly and only lasts a few seconds.

The actual star explosion, the supernova, happens instantaneously, but it evolves and becomes brighter and brighter over the next 10 - 14 days, after which it gradually becomes weaker again over the course of several months.

The spectra show that it was a metal-poor star that exploded. It only had around half the amount of heavy elements as the Sun - our star. This means that it was an early development of stars. The galaxy the star was located in was irregular and it is typically in such galaxies, that you find metal-poor massive stars in the local universe.

"It is fantastic that we can now study exploding giant stars and the related gamma ray bursts in detail - we have only been able to do this 3-4 times before", explains Johan Fynbo, who is in full swing with the detailed studies of the supernova.

Explore further: Lucky star escapes black hole with minor damage

More information: onlinelibrary.wiley.com/doi/10… 66.2010.17879.x/full

Provided by University of Copenhagen

5 /5 (10 votes)

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User comments : 8

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Tuxford
1.7 / 5 (6) Mar 10, 2011
A massive star growing rapidly from within by nucleating new matter in the high mass-density core, would be expected to be metal-poor. And, the growing mass-density therein leads to accelerating new matter (nucleation) and new energy (photon blue-shifting) production rates, leading eventually to a unstable thermal condition: boom. Leading up to this catastrophic condition, we observe in many cases the phenomenon of stellar pulsation.
omatumr
1 / 5 (9) Mar 10, 2011
The energy source is explained here ["Neutron Repulsion," The APEIRON Journal, in press (2011) 19 pages]:

http://arxiv.org/...2.1499v1
Parsec
4.1 / 5 (9) Mar 10, 2011
Is cosmology a big muddy puddle?

It MUST be because so many quacks are attracted to it.
_etabeta_
not rated yet Mar 11, 2011
"which shoots out at nearly the speed of light"
Nearly?? As far as I know gamma rays travel AT the speed of light.
MrPressure
Mar 12, 2011
This comment has been removed by a moderator.
MrPressure
Mar 12, 2011
This comment has been removed by a moderator.
yyz
5 / 5 (5) Mar 12, 2011
"2004 was Tsunam and earthquake. Next day they observe strong energypulse who coming from magnetarstar who is 50 000 lightyears faraway."

"Now they observe supernova and after one day we have earthquake and tsunam for japan!"

"What different between this happening?"

For starters, the outburst from SGR 1806-20 occurred one day AFTER the 2004 Indonesian quake-tsunami. GRB 100316D was discovered nearly a year BEFORE the March 11 quake-tsunami in Japan: http://arxiv.org/...19v3.pdf

I don't see any correlation between the two events and certainly no causation.

The magnetar outburst came from a neutron star 50 kly from us and resides in the MWG.

The GRB-SN was in a galaxy 820 Mly from Earth (and rather underluminous for a GRB or a SN at that).

The mechanisms for magnetar outbursts are quite different than what generates GRBs or SNe.

Keep in mind that while GRB-SNe are rarely observed, several examples do exist (see link above).

MrPressure
Mar 12, 2011
This comment has been removed by a moderator.
yyz
5 / 5 (6) Mar 12, 2011
"I predict the Earth was in the area between the SuperNova and Sun yesterday."

The magnetar 1806-20 is located near the ecliptic in Sagittarius. The sun was near this area (as it is every December), so I guess they may have been loosely aligned with Earth FWIW.

However, GRB 100316D is located quite far from the ecliptic in Carina, so even a loose alignment between the Sun, Earth and GRB is not possible.

Just to be clear, I see no way 'alignments' of bodies in the solar system, with objects far across our galaxy or in other galaxies, precipitate earthquakes or other natural disasters on Earth.
MrPressure
Mar 12, 2011
This comment has been removed by a moderator.
Mr_Frontier
5 / 5 (1) Mar 13, 2011
A dismal display of scientific opinion. I have never witnessed such illogically direct linkage from natural disaster to a time frame and moment of minute coincidental importance.

Are you all truly concerned or just regurgitating in abandon what has been served to you in the news this week.

I'd recommend an understandably novice chapter of "any-fucking-scientific-text", possibly within this century, to give you all an inkling of what it means to deduce a ballpark scientific opinion. Until such a day arrives, I consider the drivel on this page nearly prepubescent.

In those famous words; "I'm waiting to be impressed".
Skeptic_Heretic
5 / 5 (2) Mar 14, 2011
The energy source is explained here ["Neutron Repulsion," The APEIRON Journal, in press (2011) 19 pages]:

When Arxiv bans you, Apeiron is your last resort.

Then it hits the creationist journals.