Brightest Explosion Ever
Recorded
from RedNovaNews Website
2005/02/18
NASA -- Scientists have detected a flash of
light from across the Galaxy so powerful that it bounced off the Moon
and lit up the Earth’s upper atmosphere. The flash was brighter than
anything ever detected from beyond our Solar System and lasted over a
tenth of a second.
NASA and European satellites and many radio telescopes
detected the flash and its aftermath on December 27, 2004. Two science
teams report about this event at a special press event today at NASA
headquarters. A multitude of papers are planned for
publication.
The
scientists said the light came from a "giant flare" on the surface of an
exotic neutron star, called a magnetar. The apparent
magnitude was brighter than a full moon and all historical star
explosions. The light was brightest in the gamma-ray energy range, far
more energetic than visible light or X-rays and invisible to our
eyes.
Such a close
and powerful eruption raises the question of whether an even larger
influx of gamma rays, disturbing the atmosphere, was responsible for one
of the mass extinctions known to have occurred on Earth hundreds of
millions of years ago. Also, if giant flares can be this powerful, then
some gamma-ray bursts (thought to be very distant
black-hole-forming star explosions) could actually be from neutron
star eruptions in nearby galaxies.
NASA’s newly launched Swift satellite and the
NSF-funded Very Large Array (VLA) were two of many
observatories that observed the event, arising from neutron star SGR
1806-20, about 50,000 light years from Earth in the constellation
Sagittarius.
"This might
be a once-in-a-lifetime event for astronomers, as well as for the
neutron star," said Dr. David Palmer of Los Alamos National
Laboratory, lead author on a paper describing the Swift observation.
"We know of only two other giant flares in the past 35 years, and this
December event was one hundred times more
powerful."
Dr. Bryan
Gaensler of the Harvard-Smithsonian Center for Astrophysics in
Cambridge, Mass., is lead author on a report describing the VLA
observation, which tracked the ejected material as it flew out into
interstellar space. Other key scientific teams are associated with radio
telescopes in Australia, The Netherlands, United Kingdom, India and the
United States, as well as with NASA’s High Energy Solar
Spectroscopic Imager (RHESSI).
A neutron star is the core
remains of a star once several times more massive than our Sun. When
such stars deplete their nuclear fuel, they explode -- an event called a
supernova. The remaining core is dense, fast-spinning, highly
magnetic, and only about 15 miles in diameter. Millions of neutron stars
fill our Milky Way galaxy.
Scientists have discovered about a dozen ultrahigh-magnetic
neutron stars, called magnetars. The magnetic field around a
magnetar is about 1,000 trillion gauss, strong enough to strip
information from a credit card at a distance halfway to the moon.
(Ordinary neutron stars measure a mere trillion gauss; the Earth’s
magnetic field is about 0.5 gauss.)
Four of these
magnetars are also called soft gamma repeaters, or SGRs,
because they flare up randomly and release gamma rays. Such episodes
release about 10^30 to 10^35 watts for about a second, or up to millions
of times more energy than our Sun. For a tenth of a second, the giant
flare on SGR 1806-20 unleashed energy at a rate of about 10^40
watts. The total energy produced was more than the Sun emits in 150,000
years.
"The next
biggest flare ever seen from any soft gamma repeater was peanuts
compared to this incredible December 27 event," said Gaensler.
"Had this happened within 10 light years of us, it would have severely
damaged our atmosphere. Fortunately, all the magnetars we know
of are much farther away than this."
A scientific
debate raged in the 1980s over whether gamma-ray bursts were star
explosions from beyond our Galaxy or eruptions on nearby neutron stars.
By the late 1990s it became clear that gamma-ray bursts did indeed
originate very far away and that SGRs were a different
phenomenon. But the extraordinary giant flare on SGR 1806-20 reopens the
debate, according to Dr. Chryssa Kouveliotou of NASA Marshall
Space Flight Center, who took part in both the Swift and VLA
analysis.
A
sizeable percentage of "short" gamma-ray bursts, less than two seconds,
could be SGR flares, she said. These would come from galaxies within
about a 100 million light years from Earth. (Long gamma-ray bursts
appear to be black-hole-forming star explosions billions of light years
away.)
"An answer
to the ’short’ gamma-ray burst mystery could come any day now that
Swift is in orbit", said Swift lead scientist Neil Gehrels.
"Swift saw this event after only about a month on the
job."
Scientists
around the world have been following the December 27 event.
RHESSI detected gamma rays and X-rays from the flare. Drs.
Kevin Hurley and Steven Boggs of the University of
California, Berkeley, are leading the effort to analyze these data.
Dr. Robert Duncan of the University of Texas at Austin and Dr.
Christopher Thompson at the Canadian Institute for Theoretical
Astrophysics (University of Toronto) are the leading experts on
magnetars, and they are investigating the "short duration"
gamma-ray burst relationship.
Brian Cameron, a graduate
student at Caltech under the tutorage of Prof. Shri Kulkarni,
leads a second scientific paper based on VLA data. Amateur
astronomers detected the disturbance in the Earth’s ionosphere and
relayed this information through the American Association of Variable
Star Observers.
|
Gamma Ray flare expanding from SGR 1806-20
and impacting Earth’s atmosphere. Credit: NASA
|
|
An artist conception of the SGR 1806-20
magnetar including magnetic field lines. Credit:
NASA |
|
SGR-1806 is located about 50,000 light years
away from Earth in the constellation Sagittarius. Credit:
NASA |
|
Swift is a first-of-its-kind multi-wavelength
observatory dedicated to the study of gamma ray burst (GRB)
science. Credit: NASA |
|
High resolution, wide-field image of the area
around SGR1806-20 as seen in radio wavelength. Credit:
NASA |
Videos and
Animations
1)
Artist conception of the December 27, 2004 gamma ray flare expanding
from SGR 1806-20 and impacting Earth’s atmosphere. Click here to watch
video.
2) An artist conception of the SGR 1806-20 magnetar
including magnetic field lines. After the initial flash, smaller
pulsations in the data suggest hot spots on the rotating magnetar’s
surface. The data also shows no change in the magentar’s rotation
after the initial flash. Click here to watch
video.
3) Radio data shows a very active area around
SGR1806-20. The Very Large Array radio telescope observed ejected
material from this Magnetar as it flew out into interstellar space.
These observations in the radio wavelength start about 7 days after
the flare and continue for 20 days. They show SGR1806-20 dimming in
the radio spectrum. Click here to watch
video.
4) SGR-1806 is an ultra-magnetic neutron star,
called a magnetar, located about 50,000 light years away from Earth in
the constellation Sagittarius. Click here to watch
video.
5) Swift is a first-of-its-kind multi-wavelength
observatory dedicated to the study of gamma ray burst (GRB) science.
Its three instruments will work together to observe GRBs and
afterglows in the gamma ray, X-ray, ultraviolet, and optical
wavebands. Swift is designed to solve the 35-year-old mystery of the
origin of gamma-ray bursts. Scientists believe GRB are the birth cries
of black holes. Click here to watch
video.
6) NASA’s Swift satellite was successfully launched
Saturday, November 20, 2004 from the Cape Canaveral Air Force Station,
Fla. Click here to watch
video.
Other
observatories and scientific representatives include:
Additional
information about magentars and soft gamma ray repeaters
can be found at Dr. Robert Duncan’s web site located at the University
of Texas at Austin: http://solomon.as.utexas.edu/~duncan/magnetar.html
Huge explosion traced to
exotic star
by
Jim Giles
News -
Published online: 18 February 2005
from Nature Website
Astronomers
pinpoint source of unprecedented radiation surge.
The
rotating, highly-magnetized neutron star undergoing a ’quake’ at its
surface. Click here to see animation.
A cataclysmic ’starquake’ is
thought to have caused a flare of radiation that ripped past the Earth
on 27 December, battering instruments on satellites and lighting up our
atmosphere.
Scientists say this is the biggest blast of
gamma and X-rays they have ever observed in our corner of
the Universe. They believe the flare came from a bizarre object just 20
kilometers wide on the other side of the Galaxy.
"This is a
once-in-a-lifetime event," says Rob Fender of Southampton
University, UK, one of the researchers studying data on the flare.
"The object released more energy in a tenth of a second than the Sun
emits in 100,000 years."
Data from
satellites and ground-based telescopes have pinpointed the origin of the
burst as SGR 1806-20, a ’magnetar’ around 50,000 light-years away in the
constellation of Sagittarius. Magnetars are extremely dense,
small stars with magnetic fields at least a thousand trillion times
stronger than the Earth’s. They are a type of neutron star, the compact
remnant of a collapsed sun.
Huge explosion traced to exotic
star
Astronomically speaking, this was in our
backyard.
Bryan Gaensler
Harvard-Smithsonian Center for Astrophysics
from Nature Website
The flare may
have been caused by a quake on the surface of SGR 1806-20, suggest
researchers. The quake would have disturbed the star’s magnetic field,
creating an explosion that was the brightest ever detected beyond our
Solar System.
It is
possible that similar flares have been misinterpreted in the past.
Analogous gamma ray bursts have been detected, but they were assumed to
come from very distant objects beyond our galaxy.
A
satellite launched last November is ideally positioned to resolve the
issue. NASA’s Swift Gamma Ray Burst Mission is designed to locate and
measure bursts. "Answers to these questions could come any day now that
Swift is in orbit," says Neil Gehrels of NASA’s Goddard Space
Flight Center in Maryland.
Safe
distance
Fortunately for life on Earth, the nearest known
magnetar is about 13,000 light years away - too far for any
future burst to damage the planet. The radiation burst from a closer
explosion could, for example, wipe out the ozone layer.
"Astronomically speaking, this was in our backyard," says Bryan
Gaensler of the Harvard-Smithsonian Center for Astrophysics in
Cambridge, Massachusetts, and an author of a paper about the burst
that has been accepted for publication in Nature. "If it were in our
living room, we’d be in big trouble."
Blast Affected Earth
From Halfway Across The Milky Way
Cambridge MA (SPX) Feb 21, 2005
from SpaceDaily Website
Forget
"Independence Day" or "War of the Worlds." A monstrous cosmic explosion
last December showed that the earth is in more danger from real-life
space threats than from hypothetical alien invasions.
The
gamma-ray flare, which briefly outshone the full moon, occurred within
the Milky Way galaxy. Even at a distance of 50,000 light-years, the
flare disrupted the earth’s ionosphere.
If such a
blast happened within 10 light-years of the earth, it would destroy the
much of the ozone layer, causing extinctions due to increased
radiation.
"Astronomically speaking, this explosion happened in our
backyard. If it were in our living room, we’d be in big trouble!"
Said
Bryan Gaensler (Harvard-Smithsonian Center for Astrophysics),
lead author on a paper describing radio observations of the
event.
Gaensler headed one of two teams reporting on this
eruption at a special press event today at NASA headquarters. A
multitude of papers are planned for publication.
The giant
flare detected on December 27, 2004, came from an isolated,
exotic neutron star within the Milky Way. The flare was more
powerful than any blast previously seen in our galaxy.
"This might
be a once-in-a-lifetime event for astronomers, as well as for a
neutron star," said David Palmer of Los Alamos National
Laboratory, lead author on a paper describing space-based observations
of the burst.
"We
know of only two other giant flares in the past 35 years, and this
December event was one hundred times more
powerful."
NASA’s newly
launched Swift satellite and the NSF-funded Very Large Array (VLA) were
two of many observatories that observed the event, arising from neutron
star SGR 1806-20, about 50,000 light years from Earth in the
constellation Sagittarius.
Neutron stars form from collapsed stars. They are
dense, fast-spinning, highly magnetic, and only about 15 miles in
diameter. SGR 1806-20 is a unique neutron star called a magnetar,
with an ultra-strong magnetic field capable of stripping information
from a credit card at a distance halfway to the Moon.
Only about 10
magnetars are known among the many neutrons stars in the Milky
Way.
"Fortunately, there are no magnetars anywhere near the earth.
An explosion like this within a few trillion miles could really ruin
our day," said graduate student Yosi Gelfand (CfA), a co-author
on one of the papers.
The
magnetar’s powerful magnetic field generated the gamma-ray flare in a
violent process known as magnetic reconnection, which releases huge
amounts of energy. The same process on a much smaller scale creates
solar flares.
"This
eruption was a super-super-super solar flare in terms of energy
released," said Gaensler.
Using the
VLA and three other radio telescopes, Gaensler and his
team detected material ejected by the blast at a velocity three-tenths
the speed of light. The extreme speed, combined with the close-up view,
yielded changes in a matter of days.
Spotting
such a nearby gamma-ray flare offered scientists an incredible
advantage, allowing them to study it in more detail than ever before.
"We can see
the structure of the flare’s aftermath, and we can watch it change
from day to day. That combination is completely unprecedented," said
Gaensler.
Headquartered
in Cambridge, Mass., the Harvard-Smithsonian Center for Astrophysics
(CfA) is a joint collaboration between the Smithsonian Astrophysical
Observatory and the Harvard College Observatory. CfA scientists,
organized into six research divisions, study the origin, evolution and
ultimate fate of the universe.
Distant explosion breaks
brightness records
by Maggie
McKee
19:00 18 February 2005
from NewScientist
Website
Several dozen
satellites around Earth, and one orbiting Mars, detected a flash
of high-energy photons - known as gamma rays - on 27 December
2004. The 0.25-second flash was so bright it overwhelmed the
detectors on many satellites - making an energy measurement impossible -
and disrupted some radio communication on Earth.
"It was so
bright, it came right through the body of the Swift satellite, even
though Swift wasn’t pointed at the object," says John Nousek,
mission director for NASA’s Swift spacecraft - launched
especially to detect gamma-ray bursts (GRBs) - at Pennsylvania
State University, US.
The brief
flash was followed by a fainter afterglow of gamma rays lasting for
about 500 seconds, which showed a recurring signal every 7.5 seconds.
That signal led scientists using Europe’s INTEGRAL spacecraft to trace
the source of the "superflare" to a dead star - called a neutron
star - known to spin at that rate. Measurements of the distance to
the star - called SGR 1806-20, range from 30,000 to 50,000 light years
from Earth.
That
relatively small distance, coupled with an accurate energy measurement
by NASA’s RHESSI satellite, means the explosion was not as
powerful - at source - as more distant bursts linked with black holes.
Nevertheless, it "may have sterilized any planets within a few light
years of it", says Rob Fender, an astronomer at Southampton
University, UK, who is studying the lingering radio emission from the
flare. "This may be a once-in-a-lifetime event both for astronomers and
for the neutron star itself."
Clean credit card
But Christopher Thompson, an
astrophysicist at the Canadian Institute for Theoretical Physics, says
that may not be so. The neutron star in question is rare
magnetar, with a magnetic field so strong it could wipe a credit
card clean from a distance of 160,000 kilometers. And this
magnetar is even rarer yet, one of three "soft gamma repeaters"
(SGRs) in the Milky Way.
SGRs tend to release low-energy flares of gamma rays
sporadically, but more energetic bursts have been observed twice before
- in 1998 and 1979. But the energy in the initial 0.25-second burst from
the most recent flare was 100 times that of the two previous
superflares.
But
Thompson, who worked on the most accepted magnetar model, says:
"I wasn’t
shocked at the energy it was putting out. The total energy implied by
the models is enough to power a dozen or more of these events in the
life of one magnetar."
Superflares
may occur when tightly wrapped magnetic fields inside the magnetar start
to "untwist". This briefly rips loose some magnetic fields outside the
star, releasing a "fireball" of particles, and light that astronomers
see as a bright flash of gamma rays.
Extreme distances
If this flare had been even farther away -
up to 100 million light years or so - it would have looked
"indistinguishable" from a short GRB - a cosmic phenomenon that
has baffled astronomers for years.
Short GRBs
are blasts of high-energy gamma rays that last less than two seconds.
Astronomers are unsure of their cause but think they have a different
origin than "long" GRBs - lasting for several seconds or minutes - which
are thought to be created during the birth of black holes.
This
latest observation leads David Palmer, a Swift team member at Los
Alamos National Laboratory in New Mexico, US, to say:
"I’m fairly
confident that soft gamma repeaters account for at least some short
gamma-ray bursts."
Neil
Gehrels, principal investigator for Swift at NASA, says Swift should
be able to help settle the debate about short GRBs. Swift will study
both SGRs and short GRBs, having the capability to quickly respond to
short GRBs in order to locate them in space.
But he
laments: "It’s very unlikely we’re going to see another one of these
supergiant flares."
Related Articles
• Massive exploding stars create rare
magnetars 05 February 2005
• Swift mission sees its first gamma ray
bursts 07 January 2005
• Superbright gamma ray burst may be
closest ever 04 April
2003
Weblinks
• Swift, NASA
• INTEGRAL, ESA
• RHESSI, NASA
Monster star burst was
brighter than full Moon: astronomers
AFP
Fri
Feb 18, 2005 2:40 pm
from Able2Know Website
PARIS (AFP) -
Stunned astronomers described the greatest cosmic explosion ever
monitored -- a star burst from the other side of the galaxy that was
briefly brighter than the full Moon and swamped satellites and
telescopes.
The high-radiation flash, detected last December 27,
caused no harm to Earth but would have literally fried the planet had it
occurred within a few light years of home.
Normally reserved
skywatchers struggled for superlatives.
"This is a
once-in-a-lifetime event," said Rob Fender of Britain’s
Southampton University.
"We have observed an object only 20
kilometers (12 miles) across, on the other side of our galaxy,
releasing more energy in a 10th of a second than the Sun
emits in 100,000 years."
"It was the mother of all magnetic
flares -- a true monster," said Kevin Hurley, a research physicist at
the University of California at Berkeley.
Bryan
Gaensler of the United States’ Harvard-Smithsonian Center for
Astrophysics, described the burst as,
"maybe a
once per century or once per millennium event in our
galaxy.
"Astronomically speaking, this explosion happened in
our backyard. If it were in our living room, we’d be in big
trouble."
The blast was
caused by an eruption on the surface of a known, exotic kind of
neutron star called SGR 1806-20, located about 50,000 light
years from Earth in the constellation of Sagittarius and about three
billion times farther from us than the Sun.
A neutron star is the
remnant of a very large star near the end of its life -- a tiny,
extraordinarily dense core with a powerful magnetic field, spinning
swiftly on its axis.
When these ancient star cores finally run
out of fuel, they collapse in on themselves and explode as a
supernova.
There are millions of neutron stars in the Milky Way
but, so far, only a dozen have been found to be "magnetars":
neutron stars with an ultra-powerful magnetic
field.
Magnetars have have a magnetic field measuring
about 1,000 trillion gauss, hundreds of times more powerful than that of
any other object in the Universe.
To give an idea of this in
earthly terms, the field is so powerful that it could strip the data off
a credit card at a distance of 200,000 kilometers (120,000
miles).
SGR 1806-20 is an even rarer bird. It is one of only four
known "soft gamma repeater" (SGR) magnetars, so
called because they flare up randomly and release gamma rays in a
mammoth burst.
Why this happens is unknown. One theory is that
the energy release comes from magnetic fields which wrestle and overlap
because of the star’s spin and then snap back and reconnect, creating a
"starquake" rather like the competing faults that cause an
earthquake.
What is sure, though, is that the outpouring of
energy is massive.
The SGR 1806-20 spewed out about
10,000 trillion trillion watts, or about 100 times brighter than any
of the several "giant flares" that have been previously
recorded.
Despite this energy loss, the strange star did not even
pause, Britain’s Royal Astronomical Society (RAS)
said.
"SGR
1806-20 spins once in only 7.5 seconds. Amazingly, the December 27
event did not cause any slowing of its spin rate, as would be
expected," the RAS said.
The flare,
detected by satellites and telescopes operated by NASA (news -
web sites) and Europe, was so powerful that it bounced off the Moon and
lit up the Earth’s upper atmosphere. For over a tenth of the second, it
was actually brighter than a full Moon, and briefly overwhelmed delicate
sensors, RAS said.
Two science teams, formed by observations
provided by 20 institutes around the world, will report on the blast in
a forthcoming issue of the British weekly journal Nature.
Many
questions will be thrown up by the event, including the intriguing
speculation that the dinosaurs may have been wiped out by a similar,
closer gamma-ray explosion 65 million years ago, and not by climate
change inflicted by an asteroid impact.
"Had this
happened within 10 light years of us, it would have severely damaged
our atmosphere and possibly have triggered a mass extinction," said
lead-author Gaensler.
The good
news, he noted, is that the nearest known magnetar to Earth,
1E 2259+586, is about 13,000 light years
away.
Magnetar flare blitzed
Earth Dec. 27, could solve cosmic
mysteries
Co-authors
with Hurley, Boggs, Duncan and Thompson were
D. M. Smith of the UC Santa Cruz physics department, RHESSI and
Wind principal investigator and Space Sciences Laboratory Director
Robert Lin, and teams of U.S., Swiss, Russian, and German
scientists
This information is
co-released with The University of California, Berkeley, and co-insides
with a NASA Space Science Update
18 February
2005
from McDonaldObservatory Website
Austin, Texas
— Astronomers
around the world recorded late last year a powerful explosion of
high-energy X-rays and gamma rays — a split-second flash from the other
side of our galaxy that was strong enough to affect the Earth’s
atmosphere. The flash, called a soft gamma repeater flare, reached Earth
on Dec. 27 and was detected by at least 15 satellites and spacecraft
between Earth and Saturn, swamping most of their detectors.
Thought
to be a mighty cataclysm in a super-dense, highly magnetized star called
a magnetar, it emitted as much energy in two-tenths of a second
as the sun gives off in 250,000 years. Robert C. Duncan of the
University of Texas at Austin originally proposed and developed the
magnetar theory, along with Christopher Thompson of the
Canadian Institute of Theoretical Astrophysics.
"This is
a key event for understanding magnetars," Duncan said. Its
intrinsic power was a thousand times greater than the power of all other
stars in the galaxy put together, and at least 100 times the power of
any previous magnetar outburst in our galaxy. It was ten thousand
times brighter than the brightest supernova.
Duncan and Thompson worked with Kevin
Hurley, a research physicist at UC Berkeley who leads a major
international team studying the event, to understand the immense power
of the Dec. 27 flare. "It was the mother of all magnetic flares - a true
monster," Hurley said.
The
team’s observations and analysis are summarized in a paper that has been
submitted for publication in the journal Nature.
"Soft
gamma repeater" bursts — pinpoint flashes of highly energetic X-rays and
low-energy (soft) gamma rays coming repeatedly from one place in the sky
— were first noticed in 1979 and remained a mystery until Duncan and
Thompson proposed in 1992 that they originate from magnetically powered
neutron stars, or magnetars. Formed by the collapsing core of a
star throwing off its outer layers in a supernova explosion, neutron
stars are extremely dense, with more mass than in the Sun packed into a
ball about 10 miles across. Many neutron stars spin rapidly. These
spinning neutron stars, some rotating a thousand times a second, signal
their presence by the emission of pulsed radio waves, and are called
pulsars.
According
to Duncan, magnetars are a special kind of neutron
star. They are born rotating very quickly, which causes their
magnetic fields to get amplified. But after a few thousand years, their
intense magnetic field slows their spin to a more moderate period of one
rotation every few seconds. The magnetic fields both inside and outside
the star twist, however, and according to the theory these intense
fields can stress and move the crust much like shearing along the San
Andreas Fault. These magnetic fields are a quadrillion — a million
billion — times stronger than the field that deflects compass needles at
the Earth’s surface.
The shear
moves the crust around and the magnetic fields are tied to the crust,
generating twists in the magnetic field that can sometimes break and
reconnect in a process that sends trapped positrons and electrons flying
out from the star, annihilating each other in a gigantic explosion of
hard gamma rays.
The flare
observed Dec. 27 originated about 50,000 light years away in the
constellation Sagittarius, which means that the magnetar sits
directly opposite the center of our galaxy from the Earth in the disk of
the Milky Way Galaxy.
As the
radiation stormed through our solar system, it blitzed at least 15
spacecraft, knocking their instruments off-scale whether or not they
were pointing in the magnetar’s direction. One Russian satellite,
Coronas-F, detected gamma rays that had bounced off the Moon.
The flare
also ripped atoms apart, ionizing them, in much of the Earth’s
ionosphere for five minutes, to a deeper level than even the biggest
solar flares do, an effect noticed via its effect on long-wavelength
radio communications. Such events are unlikely to pose a danger to the
Earth because the chances that one would be close enough to the Earth to
cause serious disruption are exceedingly small.
Hurley and his team combined information from many
spacecraft, including neutron and gamma-ray detectors aboard Mars
Odyssey and many near-Earth satellites, in order to localize it to a
spot well-known to astronomers: a magnetar known as SGR
1806-20. This position was accurately confirmed by radio astronomers
at the Very Large Array in Socorro, N.M., who studied the fading radio
afterglow of the event and obtained important information about the
explosion.
The
tremendous power of the event has suggested a novel solution to a
long-standing mystery — the origins of a strange phenomenon known as
"Short-Duration Gamma Ray Bursts." Hundreds of brief, mysterious
flashes of high-energy radiation from deepest space, lasting less than
two seconds, have been measured and recorded over decades, but nobody
knew what they were.
The
similarity between the Dec. 27 burst and these short-duration bursts
lies in the brief spike of hard gamma rays that arrives first and
carries almost all the energy. In the recent burst, for example, the
hard spike lasted only two-tenths of a second. This was followed by a
"tail" of X-rays that lasted over six minutes. As the tail faded, its
brightness oscillated on a 7.56 second cycle, the known rotation period
of the magnetar.
According
to Duncan and Thompson’s theory, the oscillating X-ray
tail that followed was due to a residue of electrons, positrons and
gamma-rays trapped in the magnetar’s magnetic field. Such a hot "trapped
fireball" shrinks and evaporates over minutes, as electrons and
positrons annihilate. The measurements of Hurley’s team corroborate this
picture. The tail’s brightness appears to oscillate because the fireball
is stuck to the surface of the rotating star by the magnetic field, so
it rotates with the star like a lighthouse beacon.
Duncan and his team argue that the hard initial spike
of these giant flares is so bright that it can be detected from very far
away, meaning that some of the short flares we see are from other
galaxies, though the soft X-ray tails are too faint to be
seen.
Duncan
and his collaborators predict that if a magnetar flares as
brightly as the December 27 event within 100 million light-years
of Earth, astronomers should be able to detect it. Texas astronomers
John Scalo and Sheila Kannappan helped Duncan
estimate the rate at which such distant flares might be seen. They
estimated that of order 40% of the short bursts previously observed
could have been such magnetar bursts. There is a good probability that
the newly-launched Swift satellite will see a magnetar burst
once a month.
Launched
in November 2004 and gathering data only since January, Swift is
designed to automatically turn its X-ray telescope toward a burst in
order to accurately pin down its position.
Duncan’s
team estimates that Swift will spot an abundance of magnetars lurking in
other galaxies. In some cases, Swift’s X-ray telescope may even catch
the oscillating tail and measure the rotation period of the faraway
star.
"Swift
will open up a new field of astronomy: the study of extragalactic
magnetars," Duncan said.
Huge ’star-quake’ rocks
Milky Way
from 12thArmonic Website
It turns out that the 26th and
27th of December were not only turbulent for our planet, but
turbulent for our galaxy too. The explosion took place in the
constellation of Sagittarius. I’m very grateful to fixed star expert
Diana K Rosenberg for calculating the position and time of the
explosion, which in astrological tropical zodiac terms occurred at
01CAP28; LAT 3N 25 53; DECL 19S20; RA 18 06 18. It occurred Dec 27,
2004, at 21:30:26 UT.
BBC
- Astronomers
say they have been stunned by the amount of energy released in a star
explosion on the far side of our galaxy, 50,000 light-years away. The
flash of radiation on 27 December was so powerful that it bounced off
the Moon and lit up the Earth’s atmosphere. The blast occurred on the
surface of an exotic kind of star - a super-magnetic neutron star called
SGR 1806-20.
If the
explosion had been within just 10 light-years, Earth could have suffered
a mass extinction, it is said.
"We figure
that it’s probably the biggest explosion observed by humans within our
galaxy since Johannes Kepler saw his supernova in 1604," Dr
Rob Fender, of Southampton University, UK, told the BBC News
website.
One
calculation has the giant flare on SGR 1806-20 unleashing about
10,000 trillion trillion trillion watts.
"This is a
once-in-a-lifetime event. We have observed an object only 20km across,
on the other side of our galaxy, releasing more energy in a 10th of a
second than the Sun emits in 100,000 years," said Dr
Fender.
VLA Probes Secrets of Mysterious
Magnetar
February 18,
2005
from NationalScienceFoundation
Website
|
This graphic illustrates the VLA measurements
of the exanding fireball from the Dec. 27, 2004, outburst of the
magnetar SGR 1806-20. Each color indicates the observed size of
the fireball at a different time. The sequence covers roughly
three weeks of VLA observing. The outline of the fireball in each
case is not an actual image, but rather a "best-fit" model of the
shape that best matches the data from the VLA.
Credit: G.B.
Taylor, NRAO/AUI/NSF |
A giant flash
of energy from a supermagnetic neutron star thousands of light-years
from Earth may shed a whole new light on scientists’ understanding of
such mysterious "magnetars" and of gamma-ray bursts. In the
nearly two months since the blast, the National Science Foundation’s
Very Large Array (VLA) telescope has produced a wealth of
surprising information about the event, and "the show goes on," with
continuing observations.
The blast
from an object named SGR 1806-20 came on Dec. 27, 2004, and was
first detected by orbiting gamma-ray and X-ray telescopes. It was the
brightest outburst ever seen coming from an object beyond our own solar
system, and its energy overpowered most orbiting telescopes.
The burst of
gamma rays and X-rays even disturbed the Earth’s ionosphere, causing a
sudden disruption in some radio communications.
While the intensely
bright gamma ray burst faded in a matter of minutes, the VLA and other
radio telescopes have been tracking the explosion’s "afterglow" for
weeks, providing most of the data astronomers need to figure out the
physics of the blast.
A
magnetar is a superdense neutron star with a magnetic
field thousands of trillions of times more intense than that of the
Earth. Scientists believe that SGR 1806-20’s giant burst of energy was
somehow triggered by a "starquake" in the neutron star’s crust
that caused a catastrophic disruption in the magnetar’s magnetic field.
The magnetic disruption generated the huge burst of gamma rays and
"boiled off" particles from the star’s surface into a rapidly expanding
fireball that continues to emit radio waves for weeks or
months.
The
VLA first observed SGR 1806-20 on Jan. 3, and has been
joined by other radio telescopes in Australia, the Netherlands, and
India. Scientific papers prepared for publication based on the first
month’s radio observations report a number of key discoveries about the
object.
Scientists
using the VLA have found:
• The
fireball of radio-emitting material is expanding at roughly one-third
the speed of light.
• The expanding fireball is elongated, and may
change its shape quickly.
• Alignment of the radio waves
(polarization) confirms that the fireball is not spherical.
• The
flare emitted an amount of energy that represents a significant
fraction of the total energy stored in the magnetar’s magnetic
field.
Of the dozen
or so magnetars known to astronomers, only one other has been seen to
experience a giant outburst. In 1998, SGR 1900+14 put out a blast
similar in many respects to SGR 1806-20’s, but much weaker.
National
Radio Astronomy Observatory (NRAO) astronomer Dale Frail
observed the 1998 outburst and has been watching SGR 1806-20 for a
decade. Both magnetars are part of the small group of objects
called soft gamma-ray repeaters, because they repeatedly
experience much weaker outbursts of gamma rays.
In early
January, he was hosting a visiting college student while processing the
first VLA data from SGR 1806-20’s giant outburst.
"I
literally could not believe what I was looking at," Frail said.
"Immediately I could see that this flare was 100 times stronger than
the 1998 flare, and 10,000 times brighter than anything this object
had done before."
"I
couldn’t stay in my chair, and this student got to see a real, live
astronomer acting like an excited little kid," Frail
said.
The
excitement isn’t over, either. "The show goes on and we continue to
observe this thing and continue to get surprises," said Greg
Taylor, an astronomer for NRAO and the Kavli Institute of
Particle Astrophysics and Cosmology in Stanford, Calif..
One
VLA measurement may cause difficulties for scientists trying to
fit SGR 1806-20 into a larger picture of gamma ray bursts (GRBs).
GRBs, seen regularly from throughout the universe, come in two main
types--very short bursts and longer ones. The longer ones are generally
believed to result when a massive star collapses into a black hole,
rather than into a neutron star as in a supernova explosion.
The strength
and short duration of SGR 1806-20’s December outburst has led some
astronomers to speculate that a similar event could be seen out to a
considerable distance from Earth. That means, they say, that
magnetars may be the source of the short-period
GRBs.
That
interpretation is based to some extent on a previous measurement that
indicates SGR 1806-20 is nearly 50,000 light-years from Earth. One team
of observers, however, analyzed the radio emission from SGR 1806-20 and
found evidence that the magnetar is only about 30,000 light-years
distant. The difference, they say, reduces the likelihood that SGR
1806-20 could be a parallel for short-period GRBs.
In any case,
the wealth of information astronomers have gathered about the tremendous
December blast makes it an extremely important event for understanding
magnetars and GRBs.
Continuing Earth Changes
Cripple American Submarine and Pose New Dangers for the American
Continents
by
Sorcha Faal, and as reported to her Russian
Subscribers
January
10, 2005
from WhatDoesItMean Website
Continued energy surges, and as yet still
unexplained by Western scientists, continue to bombard the earth’s
Southern Hemispheric Regions this morning causing many widespread
and anomalous events throughout the world and affecting all of its
peoples.
Western media sources are presently reporting the dire
circumstances surrounding the United States Los Angeles Class Nuclear
Submarine San Francisco and the latest reports are saying that one
crewman has died and ‘23 other crew members are being treated aboard for
injuries including broken bones, bruises and lacerations’.
The
BBC also reports in this article that,
“The US
Navy said it did not know what the vessel had struck and was
investigating severe damage to the outside of the
submarine.”
Not being
reported by the Western media though is that the USS San
Francisco (SSN 711) is part of the United States Navy’s Pacific
Fleet, and a part of what is known as Submarine Squadron Fifteen based
out of the US Territory of Guam, located in the Mariana Islands Region
of the Pacific Ocean.
The significance of this lies in the
eruption on Anatahan Island, a part of the Mariana Islands and in
the ‘patrol zone’ of the USS San Francisco.
As related to us by
one Russian Naval Official,
“Imagine
you walking around your house at night with the lights off and someone
had re-arranged the furniture, make no mistake about it, the American
submariners ‘know’ their courses too well and are too highly trained
for this to happen suddenly. Some extreme geologic ‘change’ had
to have happened for this accident to occur.”
Could this
‘extreme geologic change’ have been this eruption?
As reported
in the Western media regarding this event we hear,
“The
volcano’s activity intensified beginning Tuesday and Wednesday last
week after months of extremely low seismic activities, which followed
the second batch of eruptions from April to June last year. The
volcano on Anatahan first erupted after centuries of dormancy
on May 10, 2003, with ash plume rising to more than 30,000
feet.”
We are also
continuing to receive reports of meteor fireballs entering the
earth’s atmosphere. Yesterday another such sighting was reported as
occurring in the United States region of Alaska, and where it is said,
“It
streaked quickly from the west to the east in a steep downward arc,
and soon wasn’t visible behind the mountains.”
More
information also continues to be received by us also relating to my
December 28, 2004 report, Evidence for Sumatra 9.0 Quake Leans towards
Meteorite Strike.
In one research report by the United States
National Geophysical Data Center (NGDC) it clearly states, and in
apparent contradiction to the known facts about The Great Tsunami of
2004, that,
“In the
Indian Ocean, however, the Indo-Australian plate is being subducted
beneath the Eurasian plate at its east margin. Therefore, most
tsunamis generated in this area are propagated toward the
southwest shores of Java and Sumatra, rather than into the Indian
Ocean.”
As recent
events have occurred however we know this not to be the case due to the
fact that the waves propagated out from a ‘center’ to all areas of the
Indian Ocean, to even the African Coast and beyond.
Numerous, yet
conflicting, Western media reports also continue to be generated about
this cataclysmic event with no regard to science fact but rather relying
on speculation alone.
Reports are varying to many extremes of sea
floor horizontal and/or vertical movement, such as one report that
states, “slippage occurred along about 1,200 km of the interface between
the tectonic plates”, and another that states that it was, “…a
600-mile-long (965km) rupture that generated a 35ft vertical
displacement in the sea floor.”
But the differences in how many
kilometers of vertical displacement did or did not occur, or how high or
low various parts of the sea floor rose or fell are not as important as
to how fast these assertions of fact were being spread by the Western
media sources.
They in fact began within hours of the cataclysm
occurring, with no scientific research being conducted and in
contradiction to what the United States National Geophysical Data Center
had reported and Prof Ravinder Kumar of the Centre of Advance
Studies in Geology, Punjab University who has said, “There is no
historic record of a tsunami in the Indian Ocean.”
This
information alone does not constitute proof of a meteorite strike
being the cause of this cataclysmic, but neither do the pronouncements
by the Western media stating the cause as being an earthquake
event. The behavior of the waves in the Indian Ocean though do
suggest a meteorite due to their concentric nature of flowing throughout
the oceans basin, where if these were caused by an earthquake would have
been omni or bi directed only as scientists have previously predicted,
and particularly in a region where no historical reports of a tsunami
had ever been recorded.
Not being connected in the Western Media
about this event either was its precursor which occurred in the
Macquarie Island region of Antarctica and was measured as an 8.2
event on the Richter scale. (An 8.2 Richter event is equal to 3 billion
tons of TNT and the 9.0 event in the Indian Ocean was equal to 32
billion tons.)
But released
almost simultaneously with the Antarctica 8.2 event was a report from
the United States space organization NASA’s Near Earth Object Program in
an ‘Asteroid Alert’ which in part said,
“For
comparison, the Barringer Meteor Crater in northern
Arizona is thought to have been created by an iron meteorite
between 30 and 100 meters in diameter. Its impact would have released
energy equivalent to about 3.5 million tons of
TNT.”
More
interesting in the light of these recent events are that these two
events have more in common than their historically rare power in that
both the Antarctica event and the Indian Ocean event are connected by
their sameness in both geological and magnetic anomalous features, and
as previously mapped by scientists.
One such other area on the
earth is known as the Cayman Trough and is located in the Northwest
Caribbean Sea.
A number of the world’s top scientists in their
fields have reported on this region in a report that in part
says,
“We review
the plate tectonic evolution of the Caribbean area based on a revised
model for the opening of the central North Atlantic and the South
Atlantic, as well based on an updated model of the motion of the
Americas relative to the Atlantic-Indian hotspot reference frame. We
focus on post-83 Ma reconstructions, for which we have combined a set
of new magnetic anomaly data in the central North Atlantic between the
Kane and Atlantis fracture zones with existing magnetic anomaly data
in the central North and South Atlantic oceans and fracture zone
identifications from a dense gravity grid from satellite altimetry to
compute North America-South America plate motions and their
uncertainties.”
As we are all
aware, the largest magnetic anomalous area in the world is located in
Russia and is named the Kursk Satellite Magnetic Anomaly
(KMA), and in the memory of our fallen heroes from the great
Russian Submarine Kursk of the same naming.
