Biggest Ever Cosmic Explosion Observed 7.5 Billion Light Years Away

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A record-breaking gamma ray burst was observed yesterday (March 19th) by NASA’s Swift satellite. After red-shift observations were analysed, astronomers realized they were looking at an explosion half-way across the Universe, some 7.5 billion light years away. This means that the burst occurred 7.5 billion years ago, when the Universe was only half the age it is now. This shatters the record for the most distant object that can be seen with the naked eye…

Gamma ray bursts (GRBs) are the most powerful explosions observed in the Universe, and the most powerful explosions to occur since the Big Bang. A GRB is generated during the collapse of a massive star into a black hole or neutron star. The physics behind a GRB is highly complex, but the most accepted model is that as a massive star collapses to form a black hole, the in falling material is energetically converted into a blast of high energy radiation. It is thought the burst is highly collimated from the poles of the collapsing star. Any local matter downstream of the burst will be vaporized. This has led to the thought that historic terrestrial extinctions over the last hundreds of millions of years could be down to the Earth being irradiated by gamma radiation from such a blast within the Milky Way. But for now, all GRBs are observed outside our galaxy, out of harms way.

An artists impression of gamma ray burst (credit: Stanford.edu)

This record-breaking GRB was observed by the Swift observatory (launched into Earth orbit in 2004) which surveys the sky for GRBs. Using its Burst Alert Telescope (BAT), the initiation of an event can be relayed to Earth within 20 seconds. Once located, the spacecraft turns all its instruments toward the burst to measure the spectrum of light emitted from the afterglow. This observatory is being used to understand how GRBs are initiated and how the hot gas and dust surrounding the event evolves.

“This burst was a whopper; it blows away every gamma ray burst we’ve seen so far.” – Neil Gehrels, Swift principal investigator, NASA Goddard Space Flight Center, Greenbelt, Md.

This particular GRB was observed in the constellation of Boötes at 2:12 a.m. (EDT), March 19th. Telescopes on the ground and in space quickly turned to Boötes to analyse the afterglow of the burst. Later in the day, the Very Large Telescope in Chile and the Hobby-Eberly Telescope in Texas measured the burst’s redshift at 0.94. From this measure, scientists were able to pinpoint our distance from the explosion. This red shift corresponds to a distance of 7.5 billion light years, signifying that this huge GRB happened 7.5 billion years ago, over half the distance across the observable universe.

Source: NASA

When Black Holes Explode: Measuring the Emission from the Fifth Dimension

Exploding primordial black holes could be detected (credit: Wired.com)

Primordial black holes are remnants of the Big Bang and they are predicted to be knocking around in our universe right now. If they were 1012kg or bigger at the time of creation, they have enough mass to have survived constant evaporation from Hawking radiation over the 14 billion years since the beginning of the cosmos. But what happens when the tiny black hole evaporates so small that it becomes so tightly wrapped around the structure of a fifth dimension (other than the “normal” three spatial dimensions and one time dimension)? Well, the black hole will explosively show itself, much like an elastic band snapping, emitting energy. These final moments will signify that the primordial black hole has died. What makes this exciting is that researchers believe they can detect these events as spikes of radio wave emissions and the hunt has already begun…

Publications about primordial black holes have been very popular in recent years. There is the possibility that these ancient singularities are very common in the Universe, but as they are predicted to be quite small, their effect on local space isn’t likely to be very observable (unlike younger, super-massive black holes at the centre of galaxies or the stellar black holes remaining after supernovae). However, they could be quite mischievous. Some primordial black hole antics include kicking around asteroids if they pass through the solar system, blasting through the Earth at high velocity, or even getting stuck inside a planet, slowly eating up material like a planetary parasite.

But say if these big bang relics never come near the Earth and we never see their effect on Earth (a relief, we can do without a primordial black hole playing billiards with near Earth asteroids or the threat of a mini black hole punching through the planet!)? How are we ever going to observe these theoretical singularities?

Eight-meter-wavelength Transient Array (credit: Virginia Tech)

Now, the ultimate observatory has been realized, but it measures a fairly observable cosmic emission: radio waves. The Eight-meter-wavelength Transient Array (ETA) run by Virginia Tech Departments of Electrical & Computer Engineering and Physics, and the Pisgah Astronomical Research Institute (PARI), is currently taking high cadence radio wave observations and has been doing so for the past few months. This basic-looking antenna system, in fields in Montgomery County and North Carolina, could receive emissions in the 29-47 MHz frequencies, giving researchers a unique opportunity to see primordial black holes as they die.

Interestingly, if their predictions are correct, this could provide evidence for the existence of a fifth dimension, a dimension operating at scales of billionths of a nanometer. If this exotic emission can be received, and if it is corroborated by both antennae, this could be evidence of the string theory prediction that there are more dimensions than the four we currently understand.

The idea we’re exploring is that the universe has an imperceptibly small dimension (about one billionth of a nanometer) in addition to the four that we know currently. This extra dimension would be curled up, in a state similar to that of the entire universe at the time of the Big Bang.” – Michael Kavic, project investigator.

As black holes are wrapped around this predicted fifth dimension, as they slowly evaporate and lose mass, eventually primordial black holes will be so stressed and stretched around the fifth dimension that the black hole will die, blasting out emissions in radio wave frequencies.

String theory requires extra dimensions to be a consistent theory. String theory suggests a minimum of 10 dimensions, but we’re only considering models with one extra dimension.” – Kavic

When the Large Hadron Collider goes online in May, it is hoped that the high energies generated may produce mini-black holes (amongst other cool things) where research can be done to look for the string theory extra dimensions. But the Eight-meter-wavelength Transient Array looking for the death of “naturally occurring” primordial black holes is a far less costly endeavour and may achieve the same goal.

Here’s an article on a theory that there could be 10 dimensions.

Source: Nature

Record Breaking “Dark Matter Web” Structures Observed Spanning 270 Million Light Years Across

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It is well documented that dark matter makes up the majority of the mass in our universe. The big problem comes when trying to prove dark matter really is out there. It is dark, and therefore cannot be seen. Dark matter may come in many shapes and sizes (from the massive black hole, to the tiny neutrino), but regardless of size, no light is emitted and therefore it cannot be observed directly. Astronomers have many tricks up their sleeves and are now able to indirectly observe massive black holes (by observing the gravitational, or lensing, effect on light passing by). Now, large-scale structures have been observed by analyzing how light from distant galaxies changes as it passes through the cosmic web of dark matter hundreds of millions of light years across…

Dark matter is believed to hold over 80% of the Universe’s total mass, leaving the remaining 20% for “normal” matter we know, understand and observe. Although we can observe billions of stars throughout space, this is only the tip of the iceberg for the total cosmic mass.

Using the influence of gravity on space-time as a tool, astronomers have observed halos of distant stars and galaxies, as their light is bent around invisible, but massive objects (such as black holes) between us and the distant light sources. Gravitational lensing has most famously been observed in the Hubble Space Telescope (HST) images where arcs of light from young and distant galaxies are warped around older galaxies in the foreground. This technique now has a use when indirectly observing the large-scale structure of dark matter intertwining its way between galaxies and clusters.

Astronomers from the University of British Columbia (UBC) in Canada have observed the largest structures ever seen of a web of dark matter stretching 270 million light years across, or 2000 times the size of the Milky Way. If we could see the web in the night sky, it would be eight times the area of the Moons disk.

This impressive observation was made possible by using dark matter gravity to signal its presence. Like the HST gravitational lensing, a similar method is employed. Called “weak gravitational lensing”, the method takes a portion of the sky and plots the distortion of the observed light from each distant galaxy. The results are then mapped to build a picture of the dark matter structure between us and the galaxies.

The team uses the Canada-France-Hawaii-Telescope (CFHT) for the observations and their technique has been developed over the last few years. The CFHT is a non-profit project that runs a 3.6 meter telescope on top of Mauna Kia in Hawaii.

Understanding the structure of dark matter as it stretches across the cosmos is essential for us to understand how the Universe was formed, how dark matter influences stars and galaxies, and will help us determine how the Universe will develop in the future.

This new knowledge is crucial for us to understand the history and evolution of the cosmos […] Such a tool will also enable us to glimpse a little more of the nature of dark matter.” – Ludovic Van Waerbeke, Assistant Professor, Department of Physics and Astronomy, UBC

Source: UBC Press Release

Forget Black Holes, How Do You Find A Wormhole?

An artists impression of what it would look like inside a wormhole. Pretty. (credit: Space.com)

Finding a black hole is an easy task… compared with searching for a wormhole. Suspected black holes have a massive gravitational effect on planets, stars and even galaxies, generating radiation, producing jets and accretion disks. Black holes will even bend light through gravitational lensing. Now, try finding a wormhole… Any ideas? Well, a Russian researcher thinks he has found an answer, but a highly sensitive radio telescope plus a truckload of patience (I’d imagine) is needed to find a special wormhole signature…

A wormhole connecting two points within spacetime.
Wormholes are a valid consequence of Einstein’s general relativity view on the universe. A wormhole, in theory, acts as a shortcut or tunnel through space and time. There are several versions on the same theme (i.e. wormholes may link different universes; they may link the two separate locations in the same universe; they may even link black and white holes together), but the physics is similar, wormholes create a link two locations in space-time, bypassing normal three dimensional travel through space. Also, it is theorized, that matter can travel through some wormholes fuelling sci-fi stories like in the film Stargate or Star Trek: Deep Space Nine. If wormholes do exist however, it is highly unlikely that you’ll find a handy key to open the mouth of a wormhole in your back yard, they are likely to be very elusive and you’ll probably need some specialist equipment to travel through them (although this will be virtually impossible).

Alexander Shatskiy, from the Lebedev Physical Institute in Moscow, has an idea how these wormholes may be observed. For a start, they can be distinguished from black holes, as wormhole mouths do not have an event horizon. Secondly, if matter could possibly travel through wormholes, light certainly can, but the light emitted will have a characteristic angular intensity distribution. If we were viewing a wormhole’s mouth, we would be witness to a circle, resembling a bubble, with intense light radiating from the inside “rim”. Looking toward the center, we would notice the light sharply dim. At the center we would notice no light, but we would see right through the mouth of the wormhole and see stars (from our side of the universe) shining straight through.

For the possibility to observe the wormhole mouth, sufficiently advanced radio interferometers would be required to look deep into the extreme environments of galactic cores to distinguish this exotic cosmic ghost from its black hole counterpart.

However, just because wormholes are possible does not mean they do exist. They could simply be the mathematical leftovers of general relativity. And even if they do exist, they are likely to be highly unstable, so any possibility of traveling through time and space will be short lived. Besides, the radiation passing through will be extremely blueshifted, so expect to burn up very quickly. Don’t pack your bags quite yet…

Source: arXiv publication

Flying Telescope Passes Its First Stage of Tests

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Telescopes on the ground – while having all sorts of good qualities – have the disadvantage of peering through the whole of the atmosphere when looking at the stars. Space-based telescopes like Hubble are an effective way around this, but launching a telescope into space and maintaining it is not exactly cheap. What about something in between the two?

This is where SOFIA (Stratospheric Observatory for Infrared Astronomy) flies in. SOFIA is a converted 747SP airliner that used to carry passengers for United Airlines and Pan Am, but now only has one voyager: an infrared telescope.

SOFIA recently completed the first phase of flight tests to determine its structural integrity, aerodynamics and handling abilities. This first series of tests were done with the door through which the telescope will peer closed, and open-door testing will begin in late 2008.

What makes SOFIA valuable is its ability to fly high in the stratosphere for observations, at around 41,000 feet (12.5km). This eliminates the atmosphere in between the ground and space, which causes turbulence in the light coming through, and also absorbs almost completely some wavelengths of infrared light.

Cloudy nights, normally the bane of observational astronomy, will not impede the ability of SOFIA. Other advantages are that scientists will be able to add specialized observing instruments for specific observations, and fly to anywhere in the world.

The telescope is 10 feet across, and weighs around 19 tons. It will look through a 16-foot high door in the fuselage to study planetary atmospheres, star formation and comets in the infrared spectrum.

During this stage of testing, the ability of the telescope to compensate for the motion and vibrations of the airplane was checked. After the first open-door tests are run this year, the mobile observatory will begin making observations in 2009, and will be completely operational in 2014.

SOFIA is a cooperation between NASA, who will maintain the plane, and the German Aerospace Center, who built and will maintain the telescope.

Source: NASA Press Release

Meteor Shower Throws Over 100 Meteors per Hour

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With over 100 meteors per hour, the Quadrantid Meteor Shower is one of the latest mergers between Google and NASA, a major asset to space research due to their successful combination of ideas and plans. This peak shower began around 0200 UTC on Friday morning, January 4th, with the jet owned by the founders of Mountain View-based Google flying amongst big science players, such as the SETI research team.

To see this spectacular sight and to partake in a scientific mission, Google carried a team of NASA scientists and their high-technology instruments on board the Google owned Gulfstream V jet, which left the Mineta San Jose International Airport on Thursday late afternoon about 4:30 p.m. Plans were made for a ten-hour flight over the Arctic, returning to home base when the meteor shower mission was accomplished with the resulting data.

The GOOG Google.com Stock Message Board is full of the things that Google has been doing to improve the world—a real biggie was to develop a cheaper solar, wind power for Earth—excellent idea from a company whose corporate motto is to “do not be evil.â€? That plan involved the creation of a research group to develop energy sources that was a cheaper renewable alternative which focuses on solar, wind and any other forms of power through the Renewable Energy “Cheaper Than Coalâ€? project. And of course, lowering Google’s power bill was top of the list before anyone else as a huge incentive.

Last September, as most are aware of, NASA and Google had launched a $2.6 million dollar agreement to let the Google co-founders house their aircraft at Moffett Field while NASA was to be allowed to use it for their science work, such as that of the Quadrantid Meteor Shower. Other prospective plans for Google are to hand out $30 million dollars to any company that successfully comes up with a plan to bring people to the moon. Another plan is to fund a space race through Google’s Lunar X Prize competition.

Original Source: NASA News Release

Perseus, Hero of the Night

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With the Moon quickly departing early evening skies, now is the time to find a hero. Thanks to attention Comet 17/P Holmes has generated, many SkyWatchers have now become familiar with the constellation Perseus, but there’s a lot more there than just a comet! Only a few days ago, Holmes passed a wonderful bright star named Mirfak – a part of the Alpha Persei Association. Viewable with the unaided eye, but best in binoculars, this young, moving cluster is also known as Melotte 20 or Collinder 39 and is around 601 light years away. What a treat to catch a comet overlaying a star cluster!

But that’s not all… As the old year ends and a new one begins, Comet Holmes will sweep round to visit with Messier 34. At a little fainter than magnitude 5, you might be able to spot this 1400 light year distant star cluster as a hazy patch with just your eyes, but its full-moon size will make it a special treat in binoculars as Holmes passes it by!

As Comet Holmes continues to spread and dim, it will round its orbital turn and head towards a great variable star – Beta Persei. For readers, the “Demon Star” – Algol – is a familiar target, but what a treat to catch this eclipsing variable with the the comet by the last week of January 2008! Keep watching this 93 light year distant star, because as regular as clockwork – every 2.867 days – it will drop from magnitude 2.1 to magnitude 3.4 in matter of hours. To calculate Algol’s changes for yourself, try using this great interactive tool provided by Sky & Telescope: The Minima Of Algol. How fun to watch an eclipse that happens on such a regular basis!

But don’t stop watching just yet! While the comet will probably dim to telescope only range by mid-February, it’s going to slide its way past NGC 1342! This small, compressed, open cluster of stars is around 6.5 magnitude and well within binocular and small telescope range. Still not enough? Then hang on as Holmes continues takes a run for the west coast and slides by NGC 1499 – the “California Nebula” around the first week of March! If you’re able to view under very dark skies, the California Nebula can be seen unaided and in binoculars, but its low surface brightness makes it tough for a
telescope. What a great opportunity for astrophotographers!

Isn’t it time to make Perseus your hero?