SUPER MASSIVE BLACK HOLE LEAVES SCIENTISTS FEELING RED

Pasadena, CA - Black holes have long been a source of mystery for both scientists and layman alike. The massive gravity wells were first postulated in 1783, just as science was truly starting to understand the nature of the universe. Since then great minds such as Albert Einstein and Robert Oppenheimer have tackled the mystery of
the Black Hole. When the term was first coined in a 1967 speech by Physicist John Wheeler, the Cosmological body suddenly thrust its way into the mainstream and became the most popular of space-borne gravity wells.

Since that rise in popularity the black hole industry has exploded. With movies and books helping to drive the popularity of the phenomenon, funding dedicated towards research has increased exponentially. Though much still remains a mystery about the cause and effects of black holes, the study has shown that their occurrence is quite common. Now though with the revelation that a nearby black hole is two to three times larger than previously thought, scientists are left reeling and a little bit red faced as questions about the reliability of their field starts to come into question.

“We did not expect it at all. This black hole is approximately 6.4 billion times the mass of the Sun and we now suspect that other black holes in neighbouring galaxies may be much larger than we previously had though,” said Karl Gebhardt of the University of Texas. “This new model gives us a much clearer picture of the size of black holes and allows us to more carefully study how they come into being and what purpose they serve. This may also help us understand the mystery behind quasars and how they function within the ecosystem of the Universe.”

The recently expanded black hole is located in the M87 galaxy, approximately 50 million light years away. Astronomers also believe that our galaxy, The Milky Way, may also have a super massive black hole at the centre of it but the veracity of that speculation is now being called into question.

“It’s a very difficult task to completely understand everything that exists in the universe. Our telescopes and satellites can only see so far, our computer models can only work on the data that we have. Cosmology after all is a very young science and it is only in the last twenty to thirty years that we have had the technology to really conduct thorough study,” said Scrape TV Science analyst Dr. Howard Poe. “That said though, science has a lot to prove. After all it postulates that God did not create the Heavens and the Earth which is a long and firmly held belief by a great many people, people who pay the taxes that pay for these kinds of studies. The obvious question for most of them is if they can underestimate the size of a black hole by this much then what else have they gotten wrong. It brings the science down to the level of speculation which opens it up for criticism.”

Modern religion, particularly the Abrahamic traditions, have eschewed any kind of rationale or logic behind the existence of the Universe and attributed it to the whims of an omniscient being. Science traditionally postulates theories and then pursues evidence to either prove or disprove those hypotheses. The two have often been in opposition.

“The biggest concern is that these black holes may be bigger still, or worse they are expanding at an incredible rate and will soon consume the known universe. If they are expanding and we have one at the centre of our universe how long will it be before we are destroyed by its gravity well? These are questions worth asking,” continued Poe. “Of course if we are doomed to destruction in a black hole in the fairly near future then this debate might well be pointless. It’s doesn’t really matter whose right and whose wrong if the planet has been utterly destroyed. This could of course be the result of a still fledgling science but of course because of that if we are on the path to destruction we may not know until it’s too late.”

Journey to the Center of the Milky Way: A Supermassive Black Hole

Take a journey to the center of our Milky Way galaxy. See what the Milky Way looks like from Earth; learn how we observe the center of our galaxy; and keep zooming in until we can learn things about the supermassive black hole that resides at the Galactic Center.

Artist's rendition of a black hole.

Black holes represent some of the most extreme environments in the Universe; places where even light can not escape! In this show, you'll learn all about what makes a black hole tick, where they come from, and why a black hole has no hair!

Black hole

Supermassive black holes found at the centers of distant galaxies undergo huge growth spurts as a result of galactic collisions, according to a new study by astronomers at Yale University and the University of Hawaii.

Their findings appear in the March 25 edition of Science Express.

As massive, gas-rich galaxies in the distant universe collide, the central black hole feeds on gas that is funneled to the center of the merger. “As a result of the violent, messy collision, the black hole also remains obscured behind a ‘veil’ of dust for between 10 million and 100 million years,” said Priyamvada Natarajan, professor of astronomy at Yale and one of the paper’s authors. After that time the dust is blown away to reveal a brightly shining quasar — the central region of a galaxy with an extremely energetic, supermassive black hole at its center — that lasts for another 100 million years, the team found.

Until now, astronomers were unsure how long the quasars spent behind the dust cloud. While unobscured quasars, which are the brightest optical objects in the early universe, were discovered in the late 1950s, examples of quasars obscured by dust were more difficult to detect, and were only discovered in the late 1990s. “For many years, astronomers believed that these sources were very rare. Now we are seeing them everywhere,” said Ezequiel Treister of the University of Hawaii, lead author of the study.

The team used observations from the Hubble, Chandra and Spitzer space telescopes to identify a large number of obscured, dust-enshrouded quasars up to 11 billion light years away, when the universe was only about one-fifth its current age. “We detected a signature of very hot dust at infrared and X-ray wavelengths to find these obscured sources,” Treister said.

“Once they had been identified, we used Hubble’s new Wide Field Camera 3 — which astronauts installed last year during the final servicing mission — to confirm that these distant quasars were actually the result of mergers,” said Kevin Schawinski, another Yale co-author.

The researchers discovered that the number of obscured quasars relative to the unobscured ones was significantly larger in the early universe than it is now, giving them a new understanding of how these objects formed and evolved over time. “We knew from theoretical models that mergers of massive, gas-rich galaxies were more frequent in the past,” said Natarajan, the theorist of the team. “Now we’ve found that these mergers are responsible for producing both the nearby obscured quasar population and their distant cousins.”

The astronomers coupled the telescope observations with estimated galaxy merger rates and theoretical models to come up with the amount of time it takes for the black hole to blow away the surrounding dust and gas and reveal the naked, bright quasar. “We found that these growing black holes spend about half their lives veiled in dust, and half their lives unveiled,” Natarajan said. “That means that, until now, we have likely been missing half of the actively growing black holes in the early universe.”

Major galaxy mergers are important triggers for star formation as well as modifying galaxy shape and structure. “This work confirms that mergers are also critical for the growth and evolution of central giant black holes, which continue to feed and gain weight during both the hidden phase and when they shine freely,” Natarajan said.

Other authors of the paper include C. Megan Urry of Yale University, David B. Sanders of the University of Hawaii and Jeyhan Kartaltepe of the University of Hawaii and the National Optical Astronomy Observatory.

Geminids Meteor shower on Friday 12th December 2008

The Geminids are Amazing!

If you see some bright lights in the sky this week, don’t set off for Bethlehem. It’s just the remnants of asteroid 3200 Phaethon. Collectively this debris is known as The Geminids Meteor shower and consists of low bright meteors. This is “the most reliable and often the most spectacular meteor shower of the year”, characterised by a multi-coloured display.

The radiant is in the region of the constellation Gemini so look in that direction for all the action.

So for those of you with not a lot to do this Friday, get on down to the The Observatory Science Centre, Herstmonceux, Hailsham, East Sussex, BN27 1RN (Tel: 01323 832731 Fax 01323 832741) for 6.30pm when they will be training their substantial telescope on the bright lights around Gemini.

Don Dixon Space Art

Meteors

The Earth travels about the Sun at 30 km/s. When the Earth enters a region containing cometary dust, the particles crash into the upper atmosphere travelling at an amazing 75 km/s. The heat and friction causes the dust to burn - we see them as shooting stars. They appear as streaks of light shooting across the night sky.

A Leonid Fireball Meteor from 1966.
Photographer: J. W. Young. Source: TMO, JPL, NASA.

There are a number of meteor showers that can be viewed from Australia. They are named after the stars or constellations from where they appear to begin their journey.

Meteorites are large meteors that pass through the atmosphere and hit the Earth. Everyday tons of meteorite dust can pass through our atmosphere undetected.

Meteor Showers visible from Australia

Meteor Shower	Activity Period	Maximum	Zenith Hourly Rate
p-Puppids	March 15 - April 28	April 23	40
h-Aquarids*	April 19 - May 28	May 4	50
Perseids	July 17 - August 24	August 12	100
Orionids*	October 2 - November 7	October 22	30
Leonids	November 14 - November 21	November 17	10-20
Geminids	December 7 - December 17	December 14	100

asteroids

Hey, here I am again……

So I hope you have read my article on the super volcano scenario. That is an event that can happen due to our earth but now the danger is from outer space. Space is one of the ventures that in unpredictable even though we have learnt quite a bit about it.

Meteorites, asteroids and comets are extraterrestrial objects that will strike earth if they come close to earth’s gravitational field. These rocks strike earth every time and are very common; it is mostly the small meteorites that fall in the oceans. But the possibility that bigger meteorites can strike is inevitable. Huge meteorites have struck earth before; there are many craters that can be found on earth like the Baringer crater in the USA. The extinction of the dinosaurs was because of a meteorite strike and during this huge impact the earth’s climate changed a lot and caused the extinction of many plant species.

If this occurs again which it will probably, the changes will be devastating. There has been close impacts with large comets before but was missed by earth due to slight changes in the comets direction. Like the super volcano the impact will cause huge pressure on life. First, these huge rocks cannot be diverted by a rocket very easily, you need a lot of nuclear power and then also there is little chance of diverting it.

At the moment the meteorite crashes onto the land, a huge fireball will be blown in all direction and the rock will push deeply into the soil. The heat from the meteorite will melt the rocks forming a pool of lave in the crater. Electromagnetic waves from the impact site will destroy all electronics with a computer chip in it. At impact rocks fly into the sky and some even into space, these rocks fallback on earth causing a shower of fireballs, and after some time there will be ashes clouding the sky blocking out sunlight completely and there will be showers of heavy ash and acid rain due to the injection of gases into the atmosphere. The temperature of the earth will rise dramatically well over the normal range causing forest fires to break out. Then after some days of soldering heat, the temperature at parts could plummet below zero degrees due to no sunlight; thus an ice age may form. If the meteorite lands in the ocean alongside these effects, tsunamis will occur and flood coastal regions. These changes will destroy all plant life and few humans will survive as evacuation at an huge size is just impossible. The plants can’t grow as there is no sunlight hence no photosynthesis but fungi will thrive as they don’t depend on photosynthesis.

But there is always hope even though these effects would destroy everything. Our earth has always recovered itself after global catastrophes and there is always a chance that people with shear will power would survive this event and animals and plants that can handle harsh conditions will thrive. So, never forget there are always good chance things will become normal again even if it seems like the end of the world.

How Asteroids are Formed

I’m sure you may of heard of an asteroid before. These objects occasionally hit the Earth and leave a big crater depending on the size of the asteroid. They are sometimes called “minor planets” and there are literally millions of asteroids scattered throughout our solar system. Asteroids are presumed to be remnants of matter that did not clump during the formation of the solar system. They are composed of rock, dust, and metal. When asteroids are first formed, the metal sinks to the center forming a metal core. The lighter rocks formed layers around the core and then with cooling, the asteroid starts becoming a solid. The first asteroid to ever of been sited was in 1801 by Giuseppe Piazzi.

The Milky Way

Our own galaxy is called the Milky Way. It contains about 200 billion stars and can be seen on a very dark night as a bright band stretching across the sky. It is a spiral galaxy, so wide that light would take 100 000 years to travel across it, and so thick that it would take 5000 years for light to pass through it. Our Sun is in one of the spiral arms, called the Orion arm, about two-thirds of the way from the centre. It moves around the centre of the galaxy just like the planets move around the Sun, and each of these orbits takes 200 million years.

The centre of the Milky Way appears to be in the constellation of Sagittarius. Astronomers now think that there is a black hole there.

We cannot see the spiral structure of the Milky Way because we are inside it. Instead we look at other spiral galaxies to try to understand our own.

The pictures below show two spiral galaxies like our own. If they were the Milky Way, the Sun would be about two-thirds of the way to the edge. This has been marked on the pictures to show where the Sun would be in our own galaxy.

How the Universe Changes

Scientists believe that the Universe began in a big explosion called the Big Bang. It started off as one tiny point, too small to see, but has been getting bigger ever since.

We don’t really know anything about the first moments of the Universe, but very early on, the Universe grew very quickly in a very short time. This is called “inflation”. When inflation ended, the Universe was 1,000,000,000,000,000,000,000,000,000 times bigger than it had been.

The Universe carried on growing much more slowly, and started to cool down. Light was made very early on, followed by dust and gas. In some places there was more of this dust and gas than in others. This was pulled in by gravity to make galaxies.



The earliest of these galaxies can be seen as faint blue dots in the Hubble Deep Field. This image covers a tiny patch of sky - only 1/30 the size of the full Moon - which seemed to be completely empty before the Hubble Space Telescope took this picture.

The Size of the Universe

We don’t know how big the Universe really is because we can’t see all the way to the edge of it. This is because light takes a long time to travel from very far off galaxies. The Universe is only 15,000,000,000 years old, which sounds like a long time but isn’t long enough for the light from some very far off galaxies to have reached us yet.

Looking at the light from distant stars is like looking back in time. If you look up at a star, the light that you see left that star millions of years ago. You are seeing the star as it looked then, not as it looks now. You would have to wait another few million years for the light that is leaving the star today to travel all the way through space to Earth before you could see how the star looks now.

How the Universe will End

We don’t really know how the Universe is going to end. It might stop growing and fall back in again in a “Big Crunch” or it might keep growing forever. At the moment it looks like the Universe is growing faster and faster, so it will probably keep growing forever.

Objects to Observe with the Faulkes

This is a list of star-related objects that can be observed with the Faulkes Telescope. They are split into sections: planetary nebulae and supernova remnants. The information about each object is given in the table. The first column is the name of the object, the second and third are the co-ordinates of where to find it in the sky. The final column indicates which of the two Faulkes telescopes the object can be viewed from, either Australia or Hawaii.The objects are listed in order of the best to observe first.

The coordinates are given in Right Ascension and Declination. Right Ascension is given in hours, minutes and seconds and is the equivalent of longitude on Earth. 00h is the equivalent of the Greenwich meridian, and the 360° full circle of the sky is split into 24 hours. The RA coordinate therefore determines the position of the object with respect to the 00h line.

Declination is the 'up and down' angle of the galaxy in the sky compared to the equator. A negative value is below the equator and a positive value is above it. Declination is measured in degrees, arcminutes and arcseconds. There are 60 arcseconds in an arcminute and 60 arcminutes in a degree.

See the section on stellar evolution for more information about these objects.

Planetary Nebulae

Name	RA	Dec	Visible From
M 76	01h 42m 19.7s	+51d 34m 32s	Hawaii
M 57	18h 53m 35.0s	+33d 01m 43s	Hawaii
M 97	11h 14m 47.8s	+55d 01m 10s	Hawaii
NGC 1514	04h 09m 16.9s	+30d 46m 33s	Hawaii

Supernova Remnants

Name	RA	Dec	Visible From
M 1	05h 34m 32s	+22d 00m 52s	Hawaii

Variable Stars, or "Stars That Change"

When looking at most stars, their brightness stays the same during our lifetime. However, some stars do change and these are called variable, or pulsating, stars. The time these stars take to change can be as short as a few hours or as long as a few months, but the brighter stars always take longer. If we measure this time, called the period, we can work out how bright the star actually is. We can then compare this to how bright the star looks from Earth, which lets us work out the distance to the star. This means we can use these stars to find the distances to the galaxies where they live. The stars usually used for these types of calculations are called Cepheids. These are very large bright stars and can be seen from a very long way away, so we can find the distance to very far-off galaxies.

Lives of Stars

Stars are formed from large clouds of dust and hydrogen gas left over from the creation of the Universe.

If the clouds are disturbed, the dust and gas will start to clump together and rub against each other, making them heat up. The cloud will start to spin as it collapses. This hot, spinning ball is called a ‘protostar’.

As more dust and gas falls into the middle, the protostar will keep heating up. If it gets hot enough, a reaction called nuclear fusion will start in the centre. This changes hydrogen into helium, and all of the star’s energy comes from this reaction. We see and feel this energy as light and heat. This is what is happening in our Sun at the moment.

When the hydrogen in the star runs out, it will grow and become a red giant. This will happen to the Sun in about 5 billion years, and it will become so big that it will reach the Earth. If the star is hot enough in the centre, a new nuclear reaction can start. This will turn helium into carbon. If it gets even hotter it may start to turn carbon into oxygen, and then oxygen into silicon.

Our Sun will not get this hot, so the nuclear reactions will stop when all the helium has turned to carbon. When this happens, the middle of the star will shrink and the outer parts will fly off into space. We call this a ‘planetary nebula.’

The star that is left is called a ‘white dwarf’. The white dwarf is about the same size as the Earth, but is much, much heavier. A chunk the size of a sugar cube would be as heavy as two large polar bears. At first the white dwarf is very hot, but it cools down and gets dimmer until it can no longer be seen. It is then called a ‘black dwarf.’ It will stay like this forever.

In bigger stars, the middle gets hot enough for other nuclear reactions to happen. When these reactions stop, the middle of the star shrinks very quickly and the outside explodes. This is called a ‘supernova’. There is then a very small and very heavy star left behind. This is called a neutron star. A lump of neutron star the size of a sugar cube would be as heavy as all of the people on the Earth put together.

An even bigger star, one more than 25 times heavier than the Sun, would shrink even more and become a black hole.

Inside a Star

Stars are balls of gas held together by gravity. Gravity is the same force that keeps us on the surface of the Earth instead of drifting off into space. The main gas in stars is called hydrogen.

We see stars because they give off a large amount of light. If you stand out in the sun, you can also feel the heat coming from it. All stars produce heat like this. Where does this energy come from?

The energy given out by stars comes from a process called “nuclear fusion” which turns hydrogen into another gas called helium. If the star is big enough and hot enough, fusion will carry on, turning the helium into other materials such as carbon and oxygen.

At each stage the new material will form in the centre, or “core”, of the star. If you could cut the star in half it would look a bit like an onion, like in the diagram below.

The Sun

The Sun is our closest star, and is very ordinary. It has a surface temperature of about 6000 C. The centre of the Sun is much hotter, at a temperature of about 15.6 million C.


The Sun turns faster at the equator than near the north and south poles. This is called “differential rotation” and is possible because the Sun is made of gas and has no solid surface.


The Sun is about 4.6 billion years old and is about half way through its lifetime.


The outer layer of the Sun that we actually see is called the photosphere. This is then surrounded by a very thin gas called the corona. The corona can only be seen during a solar eclipse, but is at a temperature of around 1 million C.


On the surface of the Sun we often see dark patches called sunspots. These are slightly cooler areas that have strong magnetic fields. The number of sunspots on the surface of the Sun changes over a length of time of about 22 years. Each sunspot will last from a few hours to a few days.


We also see big loops of hot gas coming from the Sun’s surface. These start and end at sunspots and are called "solar prominences."


As well as a lot of light and heat, the Sun also gives out a stream of very light particles called the “solar wind”. When this meets the Earth’s magnetic field, it causes the Northern and Southern Lights, called aurora.

What Are Stars?

Stars are huge balls of gas that give out large amounts of heat and light. Our Sun is just like the other stars in the sky, but it looks very different to the stars that we see at night because it is much closer.

Sizes of StarsOur Sun is about 1.4 million km across, but its size will change throughout its lifetime. This happens to all stars. White dwarf stars can be one thousand times smaller than our Sun, whilst red giant stars can be over one hundred times larger than our Sun.

The white dwarf stars are all circled. They are much smaller than the other Sun-like stars in the picture.

Colours and Temperatures

When you look up at the night sky, the stars all look white, but if you stop and look more closely, their colours are different. Some stars look redder in colour, like the star called Betelgeuse (shown on the right). These are cooler stars. Others stars look blue, like Sirius, the Dog Star. These are hot stars. Our Sun is an average yellow star. It has a surface temperature of about 6000 C.

Twinkling

When you look up at stars, many of them will seem to twinkle as you watch. Astronauts in space do not see this because it is caused by the Earth’s atmosphere. The atmosphere is made up of many different layers which bend light from the stars in a different way. As these layers move and change, the light we see also changes and the stars seem to twinkle. This is a bit like looking at the bottom of a swimming pool through the water. The black lines on the bottom seem to move around as the water moves.

Distances to Stars

Our closest star is the Sun. The other stars are much further away. The nearest is called Alpha Centauri. Even the very closest stars are much too far away for us to explore by spacecraft. It would take a rocket about 42,000 years to reach Alpha Centurai.

Measuring the Brightness of Stars

The brightness of a star is called its magnitude. The brightest stars have a magnitude of 1, while the dimmest stars that we can see have a magnitude of 6. The lower the number, the brighter the star. We can use the magnitude to work out the distance to the star.

Stars

Introduction

If you look up at the sky on a clear night, it is filled with thousands of twinkling points of light that we call stars. Between 2000 and 4000 can be seen without binoculars or a telescope, but these are just a few compared to the many billions that exist. There are more stars in the Universe than there are grains of sand on every beach in the world.

All of the stars that we can see belong to our own galaxy, the Milky Way. This is just one of many millions of galaxies that make up the Universe.

"ROSETTA STONE" FOUND TO DECODE THE MYSTERY OF GAMMA RAY BURSTS

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Scientists have pieced together the key elements of a gamma-ray burst, from star death to dramatic black hole birth, thanks to a March 29, 2003 explosion considered the "Rosetta stone" of such bursts.

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This telling March 29 burst in the constellation Leo, one of the brightest and closest on record, reveals for the first time that a gamma-ray burst and a supernova -- the two most energetic explosions known in the Universe -- occur essentially simultaneously, a quick and powerful one-two punch.

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The results appear in the June 19 issue of Nature. The burst was detected by NASA's High-Energy Transient Explorer (HETE) and observed in detail with the European Southern Observatory's Very Large Telescope (VLT) at the Paranal Observatory in Chile.

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"We've been waiting for this one for a long, long time," said Dr. Jens Hjorth, University of Copenhagen, lead author on one of three Nature letters. "The March 29 burst contains all the missing information. It was created through the core collapse of a massive star."

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The team said that the Rosetta stone burst also provides a lower limit on how energetic gamma-ray bursts truly are and rules out most theories concerning the origin of "long bursts," lasting longer than two seconds.

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Gamma-ray bursts temporarily outshine the entire Universe in gamma-ray light, packing the energy of over a million billion suns. Yet these explosions are fleeting -- lasting only seconds to minutes -- and occur randomly from all directions on the sky, making them difficult to study.

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A supernova is associated with the death of a star about eight times as massive as the Sun or more. When such stars deplete their nuclear fuel, they no longer have the energy (in the form of radiation pressure outward) to support their mass. Their cores implode, forming either a neutron star or (if there is enough mass) a black hole. The surface layers of the star blast outward, forming the colorful patterns typical of supernova remnants.

	Image 5

Scientists have suspected gamma-ray bursts and supernovae were related, but they have had little observational evidence, until March 29.

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"The March 29 burst changes everything," said co-author Dr. Stan Woosley, University of California, Santa Cruz. Just as the Rosetta stone helped us understand a lost, ancient language, this burst will serve as a tool to decode gamma-ray bursts. It's now known for certain that at least some gamma-ray bursts are produced when black holes, or perhaps very unusual neutron stars, are born inside massive stars, according to the team.

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GRB 030329, named after its detection date, occurred relatively close, approximately 2 billion light years away (at redshift 0.1685). The burst lasted over 30 seconds. ("Short bursts" are less than 2 seconds long.) GRB 030329 is among the 0.2% brightest bursts ever recorded. Its afterglow lingered for weeks in lower-energy X-ray and visible light.

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With the VLT, Hjorth and his colleagues uncovered evidence in the afterglow of a massive, rapidly expanding supernova shell, called a hypernova, at the same position and created at the same time as the afterglow. The following scenario emerged:

	Image 9

Thousands of years prior to this explosion, a very massive star, running out of fuel, let loose much of its outer envelope, transforming itself into a bluish Wolf-Rayet star. The Wolf-Rayet star -- containing about 10 solar masses worth of helium, oxygen and heavier elements -- rapidly depleted its fuel, triggering the Type Ic supernova / gamma-ray burst event. The core collapsed, without the star's outer part knowing. A black hole formed inside surrounded by a disk of accreting matter, and, within a few seconds, launched a jet of matter away from the black hole that ultimately made the gamma-ray burst.

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The jet passed through the outer shell of the star and, in conjunction with vigorous winds of newly forged radioactive nickel-56 blowing off the disk inside, shattered the star. This shattering represents the supernova event. Meanwhile, collisions among pieces of the jet moving at different velocities, all very close to light speed, created the gamma-ray burst. This "collapsar" model, introduced by Woosley in 1993, best explains the observation of GRB 030329, as opposed to the "supranova" and "merging neutron star" models.

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In previous gamma-ray bursts, scientists had found evidence of iron in the afterglow light, a signature of a star explosion. Also, the location of a supernova occurring in 1998, named SN1998bw, appeared to be in the same vicinity as a gamma-ray burst. The data was inconclusive, however, and many scientists remained skeptical of the association.

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"Supernova 1998bw whetted our appetite," said co-author Dr. Chryssa Kouveliotou of the NASA Marshall Space Flight Center in Huntsville, Ala. "But it took five more years before we could confidently say we found the smoking gun that nailed the association between gamma-ray bursts and supernovae, at least for some bursts."

"This does not mean that the gamma-ray burst mystery is solved," Woosley said. "We are confident that long bursts involve a core collapse, probably creating a black hole. We have convinced most skeptics. We cannot reach any conclusion yet, however, on what causes short gamma-ray bursts."

Short bursts might be caused by neutron star mergers. A NASA-led international satellite named Swift, to be launched in January 2004, will "swiftly" locate gamma-ray bursts and may capture short-burst afterglows, which have yet to be detected.

The VLT is the world's most advanced optical telescope, comprising four 8.2-meter reflecting Unit Telescopes and, in the future, four moving 1.8-meter Auxiliary Telescopes for interferometry. HETE was built by MIT as a mission of opportunity under the NASA Explorer Program, with collaboration among U.S. universities, Los Alamos National Laboratory, and scientists and organizations in Brazil, France, India, Italy and Japan.