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January 10, 2015

Researchers say light signal from space suggests merging black holes

Researchers say light signal from space suggests merging black holes

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Artist’s depiction of two supermassive black holes merging.
Image: NASA.

On Wednesday, George Djorgovski and collaborators reported in the journal Nature on an unusual light signal they say suggests two supermassive black holes are merging, a phenomenon never seen before, though theorized.

The discovery could clarify how black holes merge and galaxies evolve, and could also provide a better understanding of the so-called “final parsec problem” — the inability of theories to predict how, or even how quickly, the final phases of black hole mergers happen.

The team discovered the light coming from quasar PG 1302-102 in data from the Catalina Real-time Transient Survey (CTRS), which is able to study light sources from four fifths of the night sky using three ground-based US and Australian telescopes.

Coauthor and Caltech computational scientist Matthew Graham emphasized the final stages of these black hole mergers are not well understood.

Sine wave

Image: Geek3

CTRS has so far identified 20 quasars with similar signals, but Graham said this one is the best example because it has a clear signal that recurs about every five years, similar to a sine wave (see the 2D graph shown on the left).



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February 4, 2009

Stanford physicists print smallest-ever letters \’SU\’ at subatomic level of 1.5 nanometres tall

Stanford physicists print smallest-ever letters ‘SU’ at subatomic level of 1.5 nanometres tall

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Wednesday, February 4, 2009

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Stanford University view from Hoover Tower observation deck of the Quad and surrounding area, facing west
Image: User:Jawed.

A new historic physics record has been set by scientists for exceedingly small writing, opening a new door to computing’s future. Stanford University physicists have claimed to have written the letters “SU” at sub-atomic size.

Graduate students Christopher Moon, Laila Mattos, Brian Foster and Gabriel Zeltzer, under the direction of assistant professor of physics Hari Manoharan, have produced the world’s smallest lettering, which is approximately 1.5 nanometres tall, using a molecular projector, called Scanning Tunneling Microscope (STM) to push individual carbon monoxide molecules on a copper or silver sheet surface, based on interference of electron energy states.

A nanometre (Greek: νάνος, nanos, dwarf; μετρώ, metrό, count) is a unit of length in the metric system, equal to one billionth of a metre (i.e., 10-9 m or one millionth of a millimetre), and also equals ten Ångström, an internationally recognized non-SI unit of length. It is often associated with the field of nanotechnology.

“We miniaturised their size so drastically that we ended up with the smallest writing in history,” said Manoharan. “S” and “U,” the two letters in honor of their employer have been reduced so tiny in nanoimprint that if used to print out 32 volumes of an Encyclopedia, 2,000 times, the contents would easily fit on a pinhead.

In the world of downsizing, nanoscribes Manoharan and Moon have proven that information, if reduced in size smaller than an atom, can be stored in more compact form than previously thought. In computing jargon, small sizing results to greater speed and better computer data storage.

“Writing really small has a long history. We wondered: What are the limits? How far can you go? Because materials are made of atoms, it was always believed that if you continue scaling down, you’d end up at that fundamental limit. You’d hit a wall,” said Manoharan.

Scanning tunneling microscope sample under test at the University of St Andrews. Sample is MoS2 (Molybdenum Sulphide) being probed by a Platinum-Iridium tip.

In writing the letters, the Stanford team utilized an electron’s unique feature of “pinball table for electrons” — its ability to bounce between different quantum states. In the vibration-proof basement lab of Stanford’s Varian Physics Building, the physicists used a Scanning tunneling microscope in encoding the “S” and “U” within the patterns formed by the electron’s activity, called wave function, arranging carbon monoxide molecules in a very specific pattern on a copper or silver sheet surface.

“Imagine [the copper as] a very shallow pool of water into which we put some rocks [the carbon monoxide molecules]. The water waves scatter and interfere off the rocks, making well defined standing wave patterns,” Manoharan noted. If the “rocks” are placed just right, then the shapes of the waves will form any letters in the alphabet, the researchers said. They used the quantum properties of electrons, rather than photons, as their source of illumination.

According to the study, the atoms were ordered in a circular fashion, with a hole in the middle. A flow of electrons was thereafter fired at the copper support, which resulted into a ripple effect in between the existing atoms. These were pushed aside, and a holographic projection of the letters “SU” became visible in the space between them. “What we did is show that the atom is not the limit — that you can go below that,” Manoharan said.

“It’s difficult to properly express the size of their stacked S and U, but the equivalent would be 0.3 nanometres. This is sufficiently small that you could copy out the Encyclopaedia Britannica on the head of a pin not just once, but thousands of times over,” Manoharan and his nanohologram collaborator Christopher Moon explained.

The team has also shown the salient features of the holographic principle, a property of quantum gravity theories which resolves the black hole information paradox within string theory. They stacked “S” and the “U” – two layers, or pages, of information — within the hologram.

The team stressed their discovery was concentrating electrons in space, in essence, a wire, hoping such a structure could be used to wire together a super-fast quantum computer in the future. In essence, “these electron patterns can act as holograms, that pack information into subatomic spaces, which could one day lead to unlimited information storage,” the study states.

The “Conclusion” of the Stanford article goes as follows:

According to theory, a quantum state can encode any amount of information (at zero temperature), requiring only sufficiently high bandwidth and time in which to read it out. In practice, only recently has progress been made towards encoding several bits into the shapes of bosonic single-photon wave functions, which has applications in quantum key distribution. We have experimentally demonstrated that 35 bits can be permanently encoded into a time-independent fermionic state, and that two such states can be simultaneously prepared in the same area of space. We have simulated hundreds of stacked pairs of random 7 times 5-pixel arrays as well as various ideas for pathological bit patterns, and in every case the information was theoretically encodable. In all experimental attempts, extending down to the subatomic regime, the encoding was successful and the data were retrieved at 100% fidelity. We believe the limitations on bit size are approxlambda/4, but surprisingly the information density can be significantly boosted by using higher-energy electrons and stacking multiple pages holographically. Determining the full theoretical and practical limits of this technique—the trade-offs between information content (the number of pages and bits per page), contrast (the number of measurements required per bit to overcome noise), and the number of atoms in the hologram—will involve further work.
Quantum holographic encoding in a two-dimensional electron gas, Christopher R. Moon, Laila S. Mattos, Brian K. Foster, Gabriel Zeltzer & Hari C. Manoharan

The team is not the first to design or print small letters, as attempts have been made since as early as 1960. In December 1959, Nobel Prize-winning physicist Richard Feynman, who delivered his now-legendary lecture entitled “There’s Plenty of Room at the Bottom,” promised new opportunities for those who “thought small.”

Feynman was an American physicist known for the path integral formulation of quantum mechanics, the theory of quantum electrodynamics and the physics of the superfluidity of supercooled liquid helium, as well as work in particle physics (he proposed the parton model).

Nanotechnology – Energy transfer diagrammed from nano-thin layers of Sandia-grown quantum wells to the LANL nanocrystals (a.k.a. quantum dots) above the nanolayers.
Image: Marc Achermann.

Feynman offered two challenges at the annual meeting of the American Physical Society, held that year in Caltech, offering a $1000 prize to the first person to solve each of them. Both challenges involved nanotechnology, and the first prize was won by William McLellan, who solved the first. The first problem required someone to build a working electric motor that would fit inside a cube 1/64 inches on each side. McLellan achieved this feat by November 1960 with his 250-microgram 2000-rpm motor consisting of 13 separate parts.

In 1985, the prize for the second challenge was claimed by Stanford Tom Newman, who, working with electrical engineering professor Fabian Pease, used electron lithography. He wrote or engraved the first page of Charles Dickens’ A Tale of Two Cities, at the required scale, on the head of a pin, with a beam of electrons. The main problem he had before he could claim the prize was finding the text after he had written it; the head of the pin was a huge empty space compared with the text inscribed on it. Such small print could only be read with an electron microscope.

In 1989, however, Stanford lost its record, when Donald Eigler and Erhard Schweizer, scientists at IBM’s Almaden Research Center in San Jose were the first to position or manipulate 35 individual atoms of xenon one at a time to form the letters I, B and M using a STM. The atoms were pushed on the surface of the nickel to create letters 5nm tall.

In 1991, Japanese researchers managed to chisel 1.5 nm-tall characters onto a molybdenum disulphide crystal, using the same STM method. Hitachi, at that time, set the record for the smallest microscopic calligraphy ever designed. The Stanford effort failed to surpass the feat, but it, however, introduced a novel technique. Having equaled Hitachi’s record, the Stanford team went a step further. They used a holographic variation on the IBM technique, for instead of fixing the letters onto a support, the new method created them holographically.

In the scientific breakthrough, the Stanford team has now claimed they have written the smallest letters ever – assembled from subatomic-sized bits as small as 0.3 nanometers, or roughly one third of a billionth of a meter. The new super-mini letters created are 40 times smaller than the original effort and more than four times smaller than the IBM initials, states the paper Quantum holographic encoding in a two-dimensional electron gas, published online in the journal Nature Nanotechnology. The new sub-atomic size letters are around a third of the size of the atomic ones created by Eigler and Schweizer at IBM.

Experiments with Crookes tube first demonstrated the particle nature of electrons. In this illustration, the profile of the cross-shaped target is projected against the tube face at right by a beam of electrons.

A subatomic particle is an elementary or composite particle smaller than an atom. Particle physics and nuclear physics are concerned with the study of these particles, their interactions, and non-atomic matter. Subatomic particles include the atomic constituents electrons, protons, and neutrons. Protons and neutrons are composite particles, consisting of quarks.

“Everyone can look around and see the growing amount of information we deal with on a daily basis. All that knowledge is out there. For society to move forward, we need a better way to process it, and store it more densely,” Manoharan said. “Although these projections are stable — they’ll last as long as none of the carbon dioxide molecules move — this technique is unlikely to revolutionize storage, as it’s currently a bit too challenging to determine and create the appropriate pattern of molecules to create a desired hologram,” the authors cautioned. Nevertheless, they suggest that “the practical limits of both the technique and the data density it enables merit further research.”

In 2000, it was Hari Manoharan, Christopher Lutz and Donald Eigler who first experimentally observed quantum mirage at the IBM Almaden Research Center in San Jose, California. In physics, a quantum mirage is a peculiar result in quantum chaos. Their study in a paper published in Nature, states they demonstrated that the Kondo resonance signature of a magnetic adatom located at one focus of an elliptically shaped quantum corral could be projected to, and made large at the other focus of the corral.



Related news

  • “Wikinews Shorts: September 3, 2008” — Wikinews, September 3, 2008
  • “Scientist makes world’s smallest soccer pitch” — Wikinews, July 5, 2006

Sources

Wikipedia Learn more about Nanotechnology, Electron beam lithography and Stanford University on Wikipedia.
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December 13, 2008

Wikinews Shorts: December 13, 2008

Wikinews Shorts: December 13, 2008 – Wikinews, the free news source

Wikinews Shorts: December 13, 2008

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A compilation of brief news reports for Saturday, December 13, 2008.

President-Elect Obama’s inaugural donations to be listed online

President-Elect Obama in Austin, TX during the campaign. (Courtesy of Roxanne Mitchel)

The Presidential Inaugural Committee says it is “taking unprecedented steps to insure transparency in the public reporting of donors” by listing the names of individuals or organizations who donate over $200 towards President-Elect Barack Obama’s upcoming inaugural.

Logging onto http://www.pic2009.org/page/content/donors/ will show you a current list of over 169 current donors who have given at least that amount, and for most of the donors, much more. Donors include movie stars, real estate moguls, and sports stars, many of whom also contributed to Obama’s presidential campaign.

The Presidential Inaugural Committee states that it has raised almost $10 million dollars to cover the inaugural; and while that may seem like a large amount, the spending record for an inaugural is held by the current president, George W. Bush, with $42.8 million spent on his 2004 inaugural.


Scientists detect black hole at center of Milky Way Galaxy

A simulation of the black hole.

American and German astronomers have detected and confirmed that there is a ‘super-massive’ black hole at the center of the Milky Way galaxy. It is approximately 27,000 light years from Earth, and four million times bigger than the Sun. Scientists say it plays a significant role in forming all galaxies.

The 16-year study was performed using two telescopes located in Chile. They discovered it by tracking the movement of over two dozen separate stars. The study will be published next month in The Astrophysical Journal.

Sources


Zimbabwe accuses United Kingdom of causing cholera epidemic

An ally of Zimbabwean president Robert Mugabe, Information Minister Sikhanyiso Ndlovu, has said that a cholera epidemic in the country, which killed hundreds of people, was caused by the United Kingdom.

Ndlovu said of the outbreak that it was a “genocidal onslaught on the people of Zimbabwe by the British.” It was compared to a “serious biological chemical weapon”.

This comes just a day after President Mugabe announced that the cholera epidemic had been stopped, contradicting aid workers saying that the crisis was only getting worse.

Mugabe has already accused Western powers of planning to use the epidemic as a reason to oust him.

Sources


Colombia extradites drug lord to the United States

Montoya’s mugshot

Diego Montoya, who is alleged to be one of the Colombia’s most powerful drug lords, has been handed over to the United States authorities by Colombia to face trial. Montoya will face 12 charges, including those of murder, money laundering, and the trafficking of drugs. If convicted, he will serve no less than twenty years in prison.

Montoya was the leader of the Norte del Valle cartel, which is reported to have exported 70% of all the cocaine sold in both the European Union and the United States at its height. He was on the U.S. Federal Bureau of Investigation’s “Top Ten” most wanted fugitives.

Sources


Rare snowfall strikes southern United States

Snow has started falling in some southern states of the US, including Louisiana and Mississippi. As much as eight inches of snow were recorded, and thousands of people were left without power – one of Louisiana’s largest power suppliers, Cleco Corporation, reported ten thousand outages. Forecasters warned of dangerous driving conditions, and some flights at Louis Armstrong International Airport, located near New Orleans, were affected.

In New Orleans, snow fell today for the first time in four years. The largest snowfall amount for the city ever recorded is about 5 inches, on December 30, 1963.

Sources


Pin-up queen Bettie Page dies at age 85

Bettie Page, a model who became famous for her pin-up photos, has died at the age of 85. Page died of complications from a heart attack on Thursday, December 11.

She was born Bettie Mae Page on April 22, 1923 in Nashville, Tennessee. She was also one of the earliest Playmates of the Month for Playboy magazine.

Sources


Estonian law to allow voting by cell phone

The Parliament of Estonia has passed a law that will allow citizens to vote by mobile phone in the 2011 parliamentary elections. Voters will need free, authorized chips for their phones.

In last year’s elections, Estonians voted online. The country’s Reform Party proposed mobile voting in September 2007.

Sources



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June 11, 2008

Delta II rocket launches GLAST observatory

Delta II rocket launches GLAST observatory

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Wednesday, June 11, 2008

GLAST launches aboard a Delta II rocket
Image: NASA.

The Gamma-ray Large Area Space Telescope (GLAST) satellite has been launched aboard a United Launch Alliance Delta II Heavy carrier rocket. Lift-off occurred from Launch Complex 17B at the Cape Canaveral Air Force Station in Florida, United States, at 16:05 GMT. Spacecraft separation occurred about 75 minutes after launch, just before 17:20 GMT. The launch was reported to have been successful.

Another view of the launch
Image: NASA.

The Delta II rocket flew in the 7920H configuration, with nine GEM-46 solid rocket motors, and no third stage. This is the fifth flight of a Delta II Heavy, which differs from the standard Delta II in that it has more powerful solid rocket motors, originally developed for the Delta III. At 4627 kg (10201 lbs), GLAST is the heaviest payload ever launched by a Delta II. It will operate in a low Earth orbit, approximately 550 kilometres above the Earth’s surface.

GLAST will be used to study gamma rays emitted from supermassive black holes in other galaxies, and pulsars in our own galaxy. It is a replacement for the Compton Gamma Ray Observatory, which operated between April 1991 and June 2000. It will be used by scientists in France, Germany, Italy, Japan, Sweden and the United States. The spacecraft will be operated by the US space agency, NASA. The United States Department of Energy is also involved in the mission.

This is the 29th orbital launch of 2008, and the second to be conducted by a Delta II. The next Delta II launch will occur in just over a week, when a lighter configuration 7420 rocket will be used to place the Jason-2 satellite into orbit. In total, this is the 136th launch of a Delta II, the 134th successful Delta II launch, and the 81st consecutive success.



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April 14, 2008

Physicist John Wheeler dies at age 96

Physicist John Wheeler dies at age 96 – Wikinews, the free news source

Physicist John Wheeler dies at age 96

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Monday, April 14, 2008

Theoretical physicist John Archibald Wheeler died of pneumonia at his residence in Hightstown, New Jersey yesterday. Wheeler is most known in the popular culture for popularizing the term “black hole” to describe stars which had become so dense that nothing, not even light, could escape their gravitational pull. Although Wheeler initially objected to the idea, he later accepted the idea and coined the term “black hole” to describe such objects.

Wheeler was also known for his work along with Richard Feynman and others in the Manhattan Project, which produced the first nuclear fission bomb. He was later involved in the work to build the first fusion bomb. As much as he was known for his research, Wheeler was known for his skill and accomplishment in teaching.

Wheeler was born July 9, 1911, in Jacksonville, Florida and went on to earn his doctorate in physics at the early age of 21. He then went on to work in Copenhagen with Niels Bohr and later returned to the United States to become part of the Manhattan Project during World War II.

Wheeler continued to work in physics after the war and was involved in the United States Matterhorn project to build a hydrogen bomb before the Soviet Union. His politics were more militaristic than many of his fellow scientists at the time, in that he supported the Vietnam War and the building of the hydrogen bomb.

For a long time Wheeler was at Princeton University as the doctoral adviser for many prominent physicists including Kip Thorne and Nobel Prize winner Richard Feynman. Wheeler went on to the University of Texas at Austin in 1976 when Princeton’s mandatory retirement age neared.

Wheeler continued to work until near his death. Physicists both young and old have paid tribute to Wheeler; cosmologist Max Tegmark told the New York Times that Wheeler had been “the only physics superhero still standing”.

He is survived by three children, along with grandchildren and great-grandchildren.



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April 13, 2005

NASA rethinks abandoning Hubble

NASA rethinks abandoning Hubble – Wikinews, the free news source

NASA rethinks abandoning Hubble

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Wednesday, April 13, 2005

Hubble Space Telescope seen from Shuttle Discovery

In the aftermath of the Columbia space shuttle accident, which cost the lives of seven astronauts, the current chief of NASA Sean O’Keefe had decided further maintenance to the space telescope of Hubble was too dangerous, and that maintenance of the telescope would be dropped, essentially decommissioning the satellite. This caused some concern in the scientific community. A mission to repair the satellite using robots was dismissed as too complicated.

However, in light of space flight being resumed as of May 19th, the decision should be reconsidered, according to the nominee for the next chief of NASA, Griffin.

“We should revisit the earlier decision in light of what we learn after return to flight,” Griffin told the Senate Commerce committee Tuesday. He noted when NASA resumes space flight, it will be with the completely-overhauled Shuttle – effectively a new vehicle – which will require new risk-analyses.

The Hubble telescope has some major discoveries on its record, providing the first visual proof for black holes, the big bang theory and establishing for the first time the age of the universe. Hubble’s solar cells should provide it with enough power in its current state to maintain orbit until 2007. It was hoped that with servicing, the telescope could be maintained until 2011. Its replacement the James Webb telescope, which will be equipped with infra-red, will not be launched until 2010.

Sources


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March 21, 2005

Possible black hole created in US

Possible black hole created in US – Wikinews, the free news source

Possible black hole created in US

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Monday, March 21, 2005

A concept drawing of a natural Black hole by NASA

US particle physicists at Brookhaven National Laboratory in Upton, New York have created a fireball in a particle accelerator that bears a striking similarity to a black hole. It was generated at the Relativistic Heavy Ion Collider (RHIC) by smashing beams of gold nuclei together at almost the speed of light.

The collision produces a ball of plasma which is about 300 million times hotter that the surface of the Sun. The fireball can be detected because it absorbs jets of particles produced by the collision, but in this case 10 times as many jets were being absorbed as had been predicted by calculations.

Physicist Horatiu Nastase of Brown University in Providence, Rhode Island says that the calculations show that the fireball has properties similar to that of a black hole. Nastase says this could help explain why so few jets are seen coming out of the fireball. He thinks the particles are being absorbed into the core and reappearing as thermal (Hawking) radiation, just like theory predicts happens in a black hole.

Other physicists have pointed out possible holes in Nastase’s calculations. Carlos Nunez of MIT in Cambridge, Massachusetts said, “I wouldn’t say his model is wrong, but it’s clearly under construction.”

Even if Nastase turns out to be right, the black holes created pose no danger. At this scale gravity is not the dominant force in a black hole and they quickly evaporate away – this one lasted a mere 10-23 seconds, that is 10 million, billion, billionths of a second.

References

See also

  • New Scientist, 16 October 2004, p 35


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March 18, 2005

Fireball generated in U.S. laboratory resembles black hole

Fireball generated in U.S. laboratory resembles black hole

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Friday, March 18, 2005

File:Rhictunnel.jpg

The Relativistic Heavy Ion Collider
(Image missing from commons: image; log)

Brown University professor Horatiu Nastase has written a paper detailing calculations that suggest that a fireball created in the Relativistic Heavy Ion Collider at Brookhaven National Laboratory in Upton, New York, may have been a black hole.

The fireball occurred as scientists conducted experiments involving the smashing of streams of gold nuclei together in the RHIC and is reported to have been three hundred times hotter than the sun. It absorbed more than ten times the predicted amount of energy and radiated it as heat, a behavior characteristic of black holes.

Scientists have reassured the public that this phenomenon does not pose a threat; the fireball existed for one millionth of one billionth of one billionth of one second (one second divided by 10 septillion — a 1 followed by 25 zeroes) and was not dominated by gravity as previously observed black holes have been, providing the energy for their cataclysmic appetites.

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February 9, 2005

Star ousted from galaxy by black hole

Star ousted from galaxy by black hole – Wikinews, the free news source

Star ousted from galaxy by black hole

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Wednesday, February 9, 2005

A close encounter with the supermassive black hole at the center of the Milky Way has set a star on a one way trip into intergalactic space. The star, detected at the MMT Observatory in Tucson, Arizona, is zipping outward at a speed of 1.5 million miles per hour. Rocketing along at twice the galactic escape velocity, the Milky Way’s gravitational attraction doesn’t have the holding power to keep the star from disappearing into the emptiness between galaxies.

“We have never before seen a star moving fast enough to completely escape the confines of our galaxy,” Warren Brown of the Harvard-Smithsonian Center for Astrophysics (CfA) said. “We’re tempted to call it the outcast star because it was forcefully tossed from its home. Only the powerful gravity of a very massive black hole could propel a star with enough force to exit our galaxy.”

Using measurements of the star’s line-of-sight velocity, the scientists have concluded the star, cataloged as SDSS J090745.0+24507, is moving almost directly away from galactic center. Composition and age of the star also provide evidence of the star’s origin and ultimate fate. “Because this is a metal-rich star, we believe that it recently came from a star-forming region like that in the galactic center,” said Brown. Less than 80 million years were needed for the star to reach its current location, which is consistent with its estimated age.

Margaret J. Geller, Michael J. Kurtz and Scott J. Kenyon, along with Brown, will publish their find in an upcoming issue of The Astrophysical Journal.

The Harvard-Smithsonian Center for Astrophysics is based in Cambridge, Massachusetts, where scientists study the origin, evolution and ultimate fate of the universe.

References

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February 2, 2005

Swift satellite goes fully on-line

Swift satellite goes fully on-line – Wikinews, the free news source

Swift satellite goes fully on-line

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Wednesday, February 2, 2005

Swift satellite

NASA’s Swift satellite has completed all tests since its launch last November and with the Ultravioliet/Optical Telescope (UVOT) now on line, is now fully functional for the mission’s 2 year quest for gamma-ray bursts.

Swift image of Pinwheel Galaxy

The UVOT was tested on the Pinwheel Galaxy (M101).

“After many years of effort building the UVOT, it was exciting to point it toward the famous Pinwheel Galaxy, M101,” said Dr. Peter Roming, UVOT Lead Scientist at Penn State University. “The ultraviolet wavelengths in particular reveal regions of star formation in the galaxy’s wispy spiral arms. But more than a pretty image, this first-light observation is a test of the UVOT’s capabilities.”

Gamma ray bursts are some of the most powerful objects observed in the Universe and are thought to signal the birth of black holes.

Swift is designed to detect the bursts and automatically re-orient itself to gather images and data of the phenomenon. Swift detected and imaged its first official burst on January 17, 2005, before the UVOT was operational with the aid of the Burst Alert (BAT) and X-ray (XRT) telescopes activated several weeks earlier. The BAT detects the gamma-ray bursts, automatically and immediately turns the telescope, bringing the XRT and UVOT to bear on the location of the event which record detailed observations of the burst afterglow.

The UVOT is a joint product of Penn State University and the Mullard Space Science Laboratory.

See also

  • January 21, 2005: NASA’s Swift detects possible birth of black hole

References

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