Scientists test skeletons for Black Death bacteria

LONDON (AP) — Scientists digging a new railway in London have uncovered 13 skeletons that will be tested to see if they died from the Black Death plague in the 14th century.

The lead archaeologist of the Crossrail project, Jay Carver, says the location of the bodies and historical records suggest that the skeletons were found in a burial ground that opened at the start of the plague. Carver says scientists will study the bones to establish cause of death, and hope to map the DNA signature of the plague bacteria.

The plague began ravaging Europe in 1347, spreading quickly and killing an estimated 30 percent to 60 percent of the European population. Some 75 million people in all are believed to have died in the four-year pandemic, including 25 million Europeans.

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Monster Black Hole Burp Surprises Scientists

LONG BEACH, Calif. – Astronomers have discovered what appears to be colossal belch from a massive black hole at the heart of a distant galaxy. The outburst was 10 times as bright as the biggest star explosion, scientists say.

The potential super-sized black hole burp find came as astronomers studied the galaxy NGC 660, which is located 44 million light-years away in the constellation Pisces.

"The discovery was entirely serendipitous. Our observations were spread over a few years, and when we looked at them, we found that one galaxy had changed over that time from being placid and quiescent to undergone a hugely energetic outburst at the end," study researcher Robert Minchin of Arecibo Observatory in Puerto Rico said in a statement.

To determine whether the outburst was from a supernova — the explosive end of a star —  or the galaxy's core, the researchers used the High Sensitivity Array, a global network of telescopes that includes the Very Long Baseline Array, the Arecibo Telescope, the NSF's 100-meter Green Bank Telescope, and the 100-meter Effelsberg Radio Telescope in Germany.

Instead of an expanding ring of material suggesting a supernova event, the researchers found five locations with bright radio emissions clustered around the galaxy's core.

"The most likely explanation is that there are jets coming from the core, but they are precessing, or wobbling, and the hot spots we see are where the jets slammed into the material near the galaxy's nucleus," said Chris Salter, also of the Arecibo Observatory.

 Those jets, the researchers said, would mean the outburst likely came from a supermassive black hole at the heart of galaxy NGC 660. As the black hole devours dust and mass, it pulls a whirling disk of matter into its heart that spews jets of particles as it is consumed.

Supermassive black holes are colossal structures at the cores of galaxies that are between millions and billions of times as massive as the sun. They are much larger than stellar-mass black holes, which are created from the deaths of giant stars and can contain the mass of about 10 suns.

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Scientists crack Black Death's genetic code

A Wayson stain of the Yersinia pestis bacterium, responsible for the plague that ravaged Europe between 1347 and 1351.

Credit: Reuters/CDC

By Kate Kelland

LONDON | Thu Oct 13, 2011 10:28am EDT

LONDON (Reuters) - Scientists have mapped out the entire genetic map of the Black Death, a 14th century bubonic plague that killed 50 million Europeans in one of the most devastating epidemics in history.

The work, which involved extracting and purifying DNA from the remains of Black death victims buried in London's "plague pits," is the first time scientists have been able to draft a reconstructed genome of any ancient pathogen.

Their result -- a full draft of the entire Black Death genome -- should allow researchers to track changes in the disease's evolution and virulence, and lead to better understanding of modern-day infectious diseases.

Building on previous research which showed that a specific variant of the Yersinia pestis (Y. pestis) bacterium was responsible for the plague that ravaged Europe between 1347 and 1351, a team of German, Canadian and American scientists went on to "capture" and sequence the entire genome of the disease.

"The genomic data show that this bacterial strain, or variant, is the ancestor of all modern plagues we have today worldwide. Every outbreak across the globe today stems from a descendant of the medieval plague," said Hendrik Poinar, of Canada's McMaster University, who worked with the team.

"With a better understanding of the evolution of this deadly pathogen, we are entering a new era of research into infectious disease."

Major technical advances in DNA recovery and sequencing have dramatically expanded the scope of genetic analysis of ancient specimens, opening up new ways of trying to understand emerging and re-emerging infections.

Experts say the direct descendants of the same bubonic plague still exist today, killing around 2,000 people a year.

A virulent strain of E. coli bacteria which caused a deadly outbreak of infections in Germany and France earlier this year was also found to contain DNA sequences from plague bacteria.

For this study Poinar's team analysed skeletal remains from Black Death victims buried in London's East Smithfield "plague pits," which are located under what is now the Royal Mint.

By focusing on promising specimens from the dental pulp of five bodies, which had already been pre-screened for the presence of Y. pestis, they were able to extract, purify and enrich the disease's DNA and at the same time reduce the amount of background non-plague DNA which might interfere.

Linking the 1349 to 1350 dates of the skeletal remains to the genetic data allowed the researchers to calculate the age of the ancestor of Y. pestis that caused the mediaeval plague.

Poinar, whose work was published in the journal Nature, said the team found that in 660 years of evolution, the genetic map of the ancient organism had only barely changed. "The next step is to determine why this was so deadly," he said.

Johannes Krause Of Germany's University of Tubingen, who also worked on the study, said the same approach could now be used to study the genomes of all sorts of historic pathogens.

"This will provide us with direct insights into the evolution of human pathogens and historical pandemics," he said in a statement.

(Editing by Paul Casciato)

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Black hole shreds star, sparking gamma ray flash

An artist's impression of a growing supermassive black hole located in the early Universe is seen in this NASA handout illustration released on June 15, 2011.

Credit: Reuters/NASA/Chandra X-Ray Observatory/A.Hobart/Handout

By Deborah Zabarenko

WASHINGTON | Mon Jun 20, 2011 7:31am EDT

WASHINGTON (Reuters) - A monster black hole shredded a Sun-like star, producing a strangely long-lasting flash of gamma rays that probably won't be seen again in a million years, astronomers reported on Thursday.

That is definitely not the norm for gamma ray bursts, energetic blasts that typically flare up and end in a matter of seconds or milliseconds, often the sign of the death throes of a collapsing star.

"This is truly different from any explosive event we have seen before," said Joshua Bloom of the University of California-Berkeley, a co-author of research on the blast published in the journal Science.

Initially spied on March 28 by NASA's Swift spacecraft, which is trolling the universe for gamma ray bursts, this particular flash has lasted more than two months and is still going on, Bloom said in a telephone interview.

What makes this even stranger is that the black hole, located in the constellation Draco (The Dragon) about 4 billion light years, or 24 sextillion miles (38.62 sextillion km) -- 24 followed by 21 zeroes -- from Earth, was sitting quietly, not eating much, when a star about the mass of our Sun moved into range.

"We have this otherwise dormant black hole, not gobbling up an appreciable amount of mass, and along comes this star which just happens to be on some orbit which puts it close to the black hole," Bloom said.

FEEDING FRENZY

"This was a black hole which was otherwise quiescent and it sort of has an impulsive feeding frenzy on this one star," he said.

Bloom figures this may happen once per black hole per million years.

This kind of behavior is different from what active black holes generally do, which is to suck in everything their vast gravity can pull in, even light. Most galaxies, including our Milky Way, are thought to harbor black holes in their hearts.

Black holes are invisible, but astronomers can infer their existence because the material they pull in lights up before it gets sucked in.

In this case, though, the black hole feasted on one star -- about the same mass as our Sun -- with such relish that it tore the star apart before gulping it down. As it did so, the black hole emitted powerful gamma ray jets from its center as bits of the dying star were turned into energy.

The black hole's gravitational pull was so great that it exerted what's called a tidal disruption on the passing star.

Astronomers could use this observation to help them learn more about how black holes grow, Bloom said.

"We still don't understand how black holes and the universe grow," he said. "We think most black holes start off as being no more than the mass of our Sun ... How they go from 10 solar masses to a billion solar masses is critical."

There is a strong connection between the mass of black holes and the mass of the galaxies that host them, with black holes feeding on gas and stars that come near.

(Editing by Cynthia Osterman)

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Black hole shreds star, sparking gamma ray flash

An artist's impression of a growing supermassive black hole located in the early Universe is seen in this NASA handout illustration released on June 15, 2011.

Credit: Reuters/NASA/Chandra X-Ray Observatory/A.Hobart/Handout

By Deborah Zabarenko

WASHINGTON | Sat Jun 18, 2011 12:05pm EDT

WASHINGTON (Reuters) - A monster black hole shredded a Sun-like star, producing a strangely long-lasting flash of gamma rays that probably won't be seen again in a million years, astronomers reported on Thursday.

That is definitely not the norm for gamma ray bursts, energetic blasts that typically flare up and end in a matter of seconds or milliseconds, often the sign of the death throes of a collapsing star.

"This is truly different from any explosive event we have seen before," said Joshua Bloom of the University of California-Berkeley, a co-author of research on the blast published in the journal Science.

Initially spied on March 28 by NASA's Swift spacecraft, which is trolling the universe for gamma ray bursts, this particular flash has lasted more than two months and is still going on, Bloom said in a telephone interview.

What makes this even stranger is that the black hole, located in the constellation Draco (The Dragon) about 4 billion light years, or 24 sextillion miles (38.62 sextillion km) -- 24 followed by 21 zeroes -- from Earth, was sitting quietly, not eating much, when a star about the mass of our Sun moved into range.

"We have this otherwise dormant black hole, not gobbling up an appreciable amount of mass, and along comes this star which just happens to be on some orbit which puts it close to the black hole," Bloom said.

FEEDING FRENZY

"This was a black hole which was otherwise quiescent and it sort of has an impulsive feeding frenzy on this one star," he said.

Bloom figures this may happen once per black hole per million years.

This kind of behavior is different from what active black holes generally do, which is to suck in everything their vast gravity can pull in, even light. Most galaxies, including our Milky Way, are thought to harbor black holes in their hearts.

Black holes are invisible, but astronomers can infer their existence because the material they pull in lights up before it gets sucked in.

In this case, though, the black hole feasted on one star -- about the same mass as our Sun -- with such relish that it tore the star apart before gulping it down. As it did so, the black hole emitted powerful gamma ray jets from its center as bits of the dying star were turned into energy.

The black hole's gravitational pull was so great that it exerted what's called a tidal disruption on the passing star.

Astronomers could use this observation to help them learn more about how black holes grow, Bloom said.

"We still don't understand how black holes and the universe grow," he said. "We think most black holes start off as being no more than the mass of our Sun ... How they go from 10 solar masses to a billion solar masses is critical."

There is a strong connection between the mass of black holes and the mass of the galaxies that host them, with black holes feeding on gas and stars that come near.

(The distance in miles/km of black hole was corrected in paragraph 5)

(Editing by Cynthia Osterman)

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Rare Sight: Giant Black Hole Devours Star, Fires Beams at Earth (SPACE.com)

A powerful beam of energy has been spotted blasting out from the center of a massive black hole as it rips apart and devours a star in a rare sight that astronomers say likely happens only once every 100 million years, a new study finds.

When a NASA satellite first detected the intensely bright flash deep in the cosmos, astronomers initially thought it was a powerful burst of gamma rays from a collapsing star, one of the most powerful types of explosions in the universe. But, when the tremendous amount of energy could still be seen months later, they realized something more mysterious was going on.

"This is a really, really unusual event," study co-author Joshua Bloom,assistant professor of Astronomy at University of California, Berkeley, told SPACE.com. "It's now about two-and-a-half months old, and the fact that it just continues on and is only fading very slowly is the one really big piece of evidence that tells us this is not an ordinary gamma-ray burst." [Photos: Black Holes of the Universe]

NASA’s Swift Gamma Burst Mission spacecraft first detected the gamma-ray flash, called Sw 1644+57, within the constellation Draco, at the center of a galaxy nearly 4 billion light-years away.

Using Swift observations and others by the Hubble Space Telescope and the Chandra X-ray Observatory, Bloom and his colleagues concluded that the strange activity they were seeing was likely from a star being ripped apart by a massive black hole, rather than the effects of a gamma-ray burst, which typically can only be observed for about a day.

"This burst produced a tremendous amount of energy over a fairly long period of time," Bloom said. "That's because as the black hole rips the star apart, the mass swirls around like water going down a drain, and this swirling process releases a lot of energy."

These findings are published online in the June 16 issue of the journal Science.

Death of a star

Bloom's research showed that the highly energetic and long-lasting X-rays and gamma-rays were produced as a star about the size of our sun was violently shredded by a black hole a million times more massive.

But, what makes this a rare event is that this particular black hole has not been eating up matter around it like some other active black holes in the universe, Bloom said. In fact, the researchers sifted through historical records of that region of the cosmos and could not find evidence of previous long-lived X-ray or gamma-ray emissions.

"This event was not the act of gobbling lots of gas, but instead was a sort of impulsive thing," Bloom said. "This sort of thing could happen at the center of any galaxy, but the rate at which this happens is very low. It's sort of a one-off event that really shouldn't happen again." [Top 10 Strangest Things in Space]

Astronomers were even luckier to have been able to witness the event with such detail and clarity, since the jet of X-rays and high-energy gamma rays were punched out along a rotation axis that placed Earth in the eye of the beam.

“The best explanation that so far fits the size, intensity, time scale, and level of fluctuation of the observed event, is that a massive black hole at the very center of that galaxy has pulled in a star and ripped it apart by tidal disruption," said Andrew Levan of the University of Warwick in the U.K., lead author of a companion piece that was also published in Science. "The spinning black hole then created the two jets, one of which pointed straight to Earth.”

A lucky view

Essentially, astronomers here on Earth are looking down the barrel of the jet, witnessing an event which is likely to happen about once in 100 million years in any given galaxy, Bloom said.

"This is part of the special nature of the event," he said. "What we have is a geometrical rarity on top of an already rare event. I would be surprised if we saw another one of these anywhere in the sky in the next decade."

The astronomers suspect that the gamma-ray emissions began on March 24 or 25, at a distance of about 3.8 billion light-years away. And while they are still detecting activity from this event, Bloom and his colleagues estimate that the emissions will fade over the next year.

And while this may be an incredibly rare event, it does help astronomers further understand how black holes grow.

"I think this adds another piece of evidence that black holes grow organically by gobbling not just other black holes during mergers of galaxies, which is one of the ways people think black holes grow, but they also grow by eating up their surroundings in the form of gas and stars," Bloom said. "If this picture is right, black holes grow in many different ways. It addresses some unanswered question in astrophysics: these infants aren't just feeding on one baby product, namely merging with brethren, but they're gobbling up different types of foodstuffs."

You can follow SPACE.com Staff Writer Denise Chow on Twitter @denisechow. Follow SPACE.com for the latest in space science and exploration news on Twitter @Spacedotcom and on Facebook.

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Black hole shreds star, sparking gamma ray flash (Reuters)

WASHINGTON (Reuters) – A monster black hole shredded a Sun-like star, producing a strangely long-lasting flash of gamma rays that probably won't be seen again in a million years, astronomers reported on Thursday.

That is definitely not the norm for gamma ray bursts, energetic blasts that typically flare up and end in a matter of seconds or milliseconds, often the sign of the death throes of a collapsing star.

"This is truly different from any explosive event we have seen before," said Joshua Bloom of the University of California-Berkeley, a co-author of research on the blast published in the journal Science.

Initially spied on March 28 by NASA's Swift spacecraft, which is trolling the universe for gamma ray bursts, this particular flash has lasted more than two months and is still going on, Bloom said in a telephone interview.

What makes this even stranger is that the black hole, located in the constellation Draco (The Dragon) about 4 billion light years, or 24 sextillion miles (38.62 sextillion km) -- 24 followed by 21 zeroes -- from Earth, was sitting quietly, not eating much, when a star about the mass of our Sun moved into range.

"We have this otherwise dormant black hole, not gobbling up an appreciable amount of mass, and along comes this star which just happens to be on some orbit which puts it close to the black hole," Bloom said.

FEEDING FRENZY

"This was a black hole which was otherwise quiescent and it sort of has an impulsive feeding frenzy on this one star," he said.

Bloom figures this may happen once per black hole per million years.

This kind of behavior is different from what active black holes generally do, which is to suck in everything their vast gravity can pull in, even light. Most galaxies, including our Milky Way, are thought to harbor black holes in their hearts.

Black holes are invisible, but astronomers can infer their existence because the material they pull in lights up before it gets sucked in.

In this case, though, the black hole feasted on one star -- about the same mass as our Sun -- with such relish that it tore the star apart before gulping it down. As it did so, the black hole emitted powerful gamma ray jets from its center as bits of the dying star were turned into energy.

The black hole's gravitational pull was so great that it exerted what's called a tidal disruption on the passing star.

Astronomers could use this observation to help them learn more about how black holes grow, Bloom said.

"We still don't understand how black holes and the universe grow," he said. "We think most black holes start off as being no more than the mass of our Sun ... How they go from 10 solar masses to a billion solar masses is critical."

There is a strong connection between the mass of black holes and the mass of the galaxies that host them, with black holes feeding on gas and stars that come near.

(The distance in miles/km of black hole was corrected in paragraph 5)

(Editing by Cynthia Osterman)

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Monster Black Hole Twins Found Inside Galaxy's Belly (SPACE.com)

A galaxy already known to have one ginormous black hole at its core is actually home to two of these cosmic giants, a new study reveals.

Astronomers discovered the second monster black hole at the center of the galaxy Markarian 739, which is about 425 million light-years from Earth, toward the constellation Leo. Its presence was revealed in observations by NASA's Swift satellite and the Chandra X-Ray Observatory.

The two black holes are separated by about 11,000 light years, which is about one-third the distance between our solar system and the center of the Milky Way. One light-year is about 6 trillion miles (10 trillion kilometers). [Photos: Black Holes of the Universe]

Supermassive black hole twins

Both black holes are intensely active and classified as "supermassive," that is, they can each have a mindboggling mass equivalent to millions — or even billions — of stars like our sun.  Stellar black holes, formed by the collapse of massive stars, typically have up to 10 or 20 times the mass of the sun.  

"At the hearts of most large galaxies, including our own Milky Way, lies a supermassive black hole weighing millions of times the sun's mass," said the study's lead author Michael Koss,  a researcher at NASA's Goddard Space Flight Center and the University of Maryland in College Park, in a statement. "Some of them radiate billions of times as much energy as the sun."

While supermassive black holes are relatively common at the core of galaxies, not all are radiating energy to be what astronomers call "active galactic nuclei" (AGN). So it is rare to find one active monster black hole, let alone two, in the same galaxy, researchers said.

When galaxies collide

Astronomers suspect that the active binary supermassive black hole setup can occur when galaxies collide.

"If two galaxies collide and each possesses a supermassive black hole, there should be times when both black holes switch on as AGN," said study co-author Richard Mushotzky, also of the University of Maryland in College Park.

The astronomers discovered the dual black hole heart of Markarian 739 by using NASA's Swift satellite's Burst Alert Telescope, which maps intense sources of X-ray emissions in the sky, to seek out potential active galactic nuclei. Researchers can then zoom in on potential candidates with the Chandra X-Ray Observatory.

Markarian 739's second black hole was invisible in the ultraviolet, visible and radio ranges of the light spectrum, so it remained hidden until this new study, researchers said. The findings will be detailed in an upcoming edition of The Astrophysical Journal Letters.

The two giant black holes at the center of Markarian 739, which is also known by the name NGC 3758, are not the first monster black hole twins seen by astronomers, and they're not the closest either.  Both records are held by the galaxy NGC 6240, a galaxy that is about 330 million light-years from Earth.

You can follow SPACE.com Managing Editor Tariq Malik on Twitter @tariqjmalik. Follow SPACE.com for the latest in space science and exploration news on Twitter @Spacedotcom and on Facebook.

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