Excerpt from huffingtonpost.comWhat does the edge of space sound like? Pretty darn strange. Just have a listen to these acoustic signals recorded in the stratosphere some 22 miles above Earth's surface (above). At frequencies below 20 hertz, thes...
Tag: so-called (page 2 of 6)
Excerpt from nytimes.com
Leapfrogging backward in time to when the universe was apparently feeling its oats, a group of astronomers reported Tuesday that they had measured a bona fide distance to one of the farthest and thus earliest galaxies known.
The galaxy, more than a few billion light-years on the other side of the northern constellation Boötes, is one of the most massive and brightest in the early universe and goes by the name of EGS-zs8-1.
It flowered into stardom only 670 million years after the Big Bang.
The light from that galaxy has taken 13 billion years to reach telescopes on Earth. By now, however, since the universe has continued to expand during that time, the galaxy is about 30 billion light-years away, according to standard cosmological calculations.
The new measurements allow astronomers to see the galaxy in its infancy. Despite its relative youth, however, it is already about one-sixth as massive as the Milky Way, which is 10 billion years old. And it is getting bigger, making stars 80 times faster than the Milky Way is making them today. The discovery was reported in The Astrophysical Journal by Pascal Oesch of Yale University and his colleagues.
By the rules of the expanding universe, the farther away a galaxy is, the faster it is retreating from us, measured by the “redshift” of its light being broadened to longer wavelengths, the way an ambulance siren seems to lower its pitch as it goes by.
In the past few years, as astronomers have raced one another into the past with instruments like the Hubble Space Telescope, galaxies have been found that appear even more distant. Those measurements, however, were estimates based on the colors of the objects — so-called photometric redshifts.
The new galaxy stuck out in a survey of distant galaxies by the Hubble and Spitzer space telescopes known as Candels, for Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey. Its redshift was precisely measured with a powerful spectrograph known as Mosfire — Multi-Object Spectrometer for Infrared Exploration — on Keck 1, one of a pair of 10-meter-diameter telescopes on Mauna Kea in Hawaii. That makes it the highest redshift confirmed in this way, said Garth Illingworth, of the University of California, Santa Cruz, one of the astronomers in the study.
How galaxies were able to form and grow so rapidly after the lights came on in the universe is a mystery that will be addressed by a coming generation of instruments like the James Webb Space Telescope and the Thirty Meter Telescope, a goliath planned for Mauna Kea, already home to a dozen telescopes.
Recently, however, construction of the Thirty Meter Telescope, a $1.4 billion project, has been halted by protests by Hawaii residents who feel their mountain has been abused. An echo of that controversy appears in the new paper, in which Dr. Oesch and his colleagues write: “The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Mauna Kea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain.”
Reuters
With the right expertise in molecular biology, one could start a basic laboratory to modify human embryos using a genome-editing computer technique all for a couple thousand dollars, according to a new report.
Genetic modification has received heightened scrutiny recently following last week’s announcement that Chinese researchers had, for the first time, successfully edited human embryos’ genomes.
The team at Sun Yat-Sen University in Guangzhou, China, used CRISPR (clustered regularly interspaced palindromic repeats), a technique that relies on “cellular machinery” used by bacteria in defense against viruses.
This machinery is copied and altered to create specific gene-editing complexes, which include the wonder enzyme Cas9. The enzyme works its way into the DNA and can be used to alter the molecule from the inside. The combination is attached to an RNA guide that takes the gene-editing complex to its target, telling Cas9 where to operate.
Use of the CRISPR technique is not necessarily relegated to the likes of cash-flush university research operations, according to a report by Business Insider.
"You could conceivably set up a CRISPR lab for $2,000,” he said, according to Business Insider.
Other top researchers have echoed this sentiment.
"Any scientist with molecular biology skills and knowledge of how to work with [embryos] is going to be able to do this,” Jennifer Doudna, a biologist at the University of California, Berkeley, recently told MIT Tech Review, which reported that Doudna co-discovered how to edit genetic code using CRISPR in 2012.
Last week, the Sun Yat-Sen University research team said it attempted to cure a gene defect that causes beta-thalassemia (a genetic blood disorder that could lead to severe anemia, poor growth, skeletal abnormalities and even death) by editing the germ line. For that purpose they used a gene-editing technique based on injecting non-viable embryos with a complex, which consists of a protective DNA element obtained from bacteria and a specific protein.
"I suspect this week will go down as a pivotal moment in the history of medicine," wrote science journalist Carl Zimmer for National Geographic.
Response to the new research has been mixed. Some experts say the gene editing could help defeat genetic diseases even before birth. Others expressed concern.
“At present, the potential safety and efficacy issues arising from the use of this technology must be thoroughly investigated and understood before any attempts at human engineering are sanctioned, if ever, for clinical testing,” a group of scientists, including some who had worked to develop CRISPR, warned in Science magazine.
Meanwhile, the director of the US National Institutes for Health (NIH) said the agency would not fund such editing of human embryo genes.
“Research using genomic editing technologies can and are being funded by NIH,” Francis Collins said Wednesday. “However, NIH will not fund any use of gene-editing technologies in human embryos. The concept of altering the human germline in embryos for clinical purposes ... has been viewed almost universally as a line that should not be crossed.”
Although the discovery of CRISPR sequences dates back to 1987 – when it was first used to cure bacteria of viruses – its successes in higher animals and humans were only achieved in 2012-13, when scientists achieved a revolution by combining the resulting treatment system with Cas9 for the first time.
On April 17, the MIT’s Broad Institute announced that has been awarded the first-ever patent for working with the Crisp-Cas9 system.
The institute’s director, Eric Lander, sees the combination as “an extraordinary, powerful tool. The ability to edit a genome makes it possible to discover the biological mechanisms underlying human biology.”
The system’s advantage over other methods is in that it can also target several genes at the same time, working its way through tens of thousands of so-called 'guide' RNA sequences that lead them to the weapon to its DNA targets.
Meanwhile, last month in the UK, a healthy baby was born from an embryo screened for genetic diseases, using karyomapping, a breakthrough testing method that allows doctors to identify about 60 debilitating hereditary disorders.
If you mention the word secession most people think of the South during the Civil War. But today, a new movement is gaining steam because of frustration over a growing, out-of-control federal government.
A number of conservative, rural Americans are taking about seceding and creating their own states, meaning a new map of the United States of America could include the following:
- A 51st state called Jefferson, made up of Northern California and Southern Oregon
- A new state called Western Maryland
- A new state called North Colorado
These are real movements gaining traction with voters across the country. Jeffrey Hare runs the 51st State Initiative in Colorado, an effort to fight an out-of-control legislature trying to ram big government policies down the throats of voters.
"We're at this point of irreconcilable differences," Hare told CBN News.
Secessionist talk has filled town hall meetings and the divide discussed is not just ideological.
"It's predominately left versus right, but it's urban versus rural because you typically find more typical conservative values in rural America," Hare said.
An Attack on Colorado?
That's the crux of the issue. Rural Americans across many states feel they're not being heard. Their laundry list is long and at the top of that list are stricter gun control laws.
According to Weld County, Colo., Sheriff John Cooke, the state legislature is out of control.
"They are out of touch with rural Colorado," he said. "There is an attack on rural Colorado and it's not just on gun control laws. It's on several of the other bills that they passed."
Government mandates on renewable energy, environmental policies restricting oil and gas drilling, and controversial social issues like gay marriage have also led to this divide and talk of secession.
Organizers want to create "North Colorado," an idea that went to voters in 11 counties this past fall. But not everyone in Colorado thinks secession is a great idea.
"I don't think that's necessarily the way to make something happen within the area you live," Colorado resident Greg Howe told CBN News. "You're supposed to work within our electoral services."
The so-called secession movement in Colorado had mixed results this past November. Some counties approved it. Others didn't.
But the organizers of the 51st State Initiative are undaunted, saying this type of movement takes time.
"Movements take a while; education takes time," Hare said. "People do have a hard time saying ,'I want to live in a different state,' even though physically they live in the same house."
"It's hard for them since their lives have been Coloradoans," he explained. "Their whole lives to say that 'I'm going to be a new Coloradoan' or 'I want to live in the state of liberty' or something different."
An 'Amicable' Divorce
That desire for something different can also be felt in Arizona, Michigan, and in Western Maryland where thousands have signed secession petitions.
One website reads, "We intend to exercise our right of self-determination and self-governance to better secure our rights to life, liberty, and the pursuit of happiness."
Scott Strzelczyk, the leader of the Western Maryland movement, is ready to get going.
"If they are not going to listen or take our needs into consideration and govern in a way that's more in accordance with the way we want to be governed we are seeking an amicable divorce," he said.
Meanwhile, in Northern California and Southern Oregon, activists want to come together in the state of "Jefferson."
Their proposed state flag includes two "Xs," representing their feeling of being double-crossed by the state capitals of Sacramento, Calif., and Salem, Ore.
No Small Task
Creating a new state isn't easy. The last time a state actually gave up territory was in 1820, when Maine split from Massachusetts. Since then, additional efforts have been unsuccessful.
The first step is getting it passed by the state legislature and then the U.S. Congress.
"This is a valid constitutional process that our founding fathers specifically wrote into the Constitution," Hare said. "Well, if they didn't write this into the Constitution to be used, then why did they write it in?"
But supporters have an uphill battle since the media will not be their friend.
"The danger is once the outside media start to grab hold of it, the attention is on the difficulty, the almost impossibility of it happening," professor Derek Everett, with Metropolitan State University in Denver, explained.
Voter 'Disconnect'
State secession proponents, like Roni Bell Sylvester of Colorado, say they will keep fighting because the dismissive attitude of state legislative bodies must end.
"I find the sort of arrogant, dismissive to be further proof as to just how disconnected the urban is from the rural," Sylvester said.
Movements like the one in Colorado and other states could be just the beginning—at least that's the talk at town hall meetings in places like Colorado and elsewhere.
It's called 'voter disconnect" where the people say they've had enough and are crying out for something to be done.
"We, at some point, have to figure out a way to get our point across or at least be able to have a dialogue and not be ignored because you haven't seen anything yet over the next 5 to 10 years," one resident warned at a recent town hall meeting in Colorado.
As for Hare, he said it boils down to one simple concept.
"I think ultimately what people want, whether you look at it from a right or left paradigm, is government to stay out of their business," he said.
Excerpt from stgist.com
The sun, or the nearest star from Earth, was formed around 5 billion years after the Milky Way galaxy’s peak production of stars, a new research published in the Astrophysical Journal.
It’s like traveling back in time. Researchers from Texas A&M University in College Station, headed by astronomer Casey Papovich, were able to see the undepicted past of our own galaxy by observing similar regions located billions of light years away from us.
The “baby boom” happened around 10 billion years ago, the new study published in Astrophysical Journal revealed. At that time, the Milky Way galaxy was producing 30 times more stars than today. If so, then our solar system’s 4.6 billion years old Sun was formed more than 5 billion years after the production peak.
Sun’s late formation allowed the solar system we know today to produce planets with heavier elements. Scientists say elements heavier than hydrogen and helium became more abundant in “late to the game systems”, and the death of massive stars that were formed before the Sun had provided materials needed to form planets, including Earth and its complex life forms.
Scientists scanned through a collection of more than 24,000 galaxies, and took at least 2,000 snapshots of galaxies that closely resemble our own. The census has provided the most complete picture yet of how spiral galaxies similar to Milky Way form in the universe.
According to Mr. Papovich, the lead author of the study who also serves as an associate professor in the Department of Physics and Astronomy at A&M University in Texas, they know where to find traces by analyzing how galaxies like our own were formed.
Papovich said his team has provided a data that clearly show the rapid phase of growth around 9 to 10 billion years ago, or at least more than 5 billion years after our Sun formed. They also found the connection between the size of the galaxy, and the formation of stars.
Surprisingly, the robust collection of distant galaxies confirmed that stars formed inside the Milky Way, instead of forming in other smaller baby galaxies that later merged to join the system.
In separate studies, scientists were able to confirm that our own solar system is wetter than thought. Beyond Earth, celestial objects like Jupiter’s Galilean moons Europa and Ganymede, Saturn’s Enceladus, and even the dwarf planet Ceres in the asteroid belt, are hosting fluid slightly similar to Earth’s — and it is highly possible that the Sun’s late formation allowed this setup to exist.
Papovich who worked alongside Texas A&M postdoctoral researchers Vithal Tilvi and Ryan Quadri, were joined by at least two dozen astronomers from other countries. The research is published April 9th entitled “ZFOURGE/CANDELS: ON THE EVOLUTION OF M* GALAXY PROGENITORS FROM z = 3 TO 0.5*.” The research was funded by NASA
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| Nova Vulpeculae 1670 |
Excerpt from thespacereporter.com
A mystery explosion in the night sky turns out to have been caused by colliding stars.
One of history’s mysteries revolved around a strange explosion observed in the sky in 1670, long thought to have been the first nova on record. Recent research suggests that this enigmatic event was actually a rare stellar collision.
According to a report by Astronomy Magazine, the so-called Nova Vulpeculae of 1670 was more likely the collision of two stars, which shines brighter than a nova but not as brightly as a supernova.
Observations made with various telescopes including the Submillimeter Array, the Effelsburg radio telescope and APEX have revealed the more unusual nature of the light source – a violent collision.
When the event first occurred, it would have been visible from Earth with the naked eye. Now, submillimeter telescopes are needed to detect the traces left in the aftermath of the event.
When first observed, 17th century astronomers described what they saw as a new star appearing in the head of Cygnus, the swan constellation.
Having observed the area of the supposed nova with both submillimeter and radio wavelengths, scientists “have found that the surroundings of the remnant are bathed in a cool gas rich in molecules with a very unusual chemical composition,” said Kaminski.
Researchers concluded that the amount of cool material they observed was too much to have been produced by a nova. The nature of the gas debris best fit with the rare scenario of two stars merging in an explosive collision.
The team’s report was published in the journal Nature.
Karl Menten of the Max Planck Institute called the discovery “the most fun – something that is completely unexpected.”
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| (Photo : NASA/ESA) In early days of solar system, Jupiter destroyed everything that came in its way, researchers have found. |
Excerpt from latimes.com
Before Mercury, Venus, Earth and Mars occupied the inner solar system, there may have been a previous generation of planets that were bigger and more numerous – but were ultimately doomed by Jupiter, according to a new study.
If indeed the early solar system was crowded with so-called super-Earths, it would have looked a lot more like the planetary systems found elsewhere in the galaxy, scientists wrote Monday in the Proceedings of the National Academy of Sciences.
As NASA’s Kepler space telescope has found more than 1,000 planets in orbit around other stars, along with more than 4,000 other objects that are believed to be planets but haven’t yet been confirmed. Kepler finds these planets by watching their host stars and registering tiny drops in their brightness – a sign that they are being ever-so-slightly darkened by a planet crossing in front of them.
In addition, ground-based telescopes have detected hundreds of exoplanets by measuring the wiggles of distant stars. Those stars wiggle thanks to the gravitational pull of orbiting planets, and the Doppler effect makes it possible to estimate the size of these planets.
The more planetary systems astronomers discovered, the more our own solar system looked like an oddball. Exoplanets – at least the ones big enough for us to see – tended to be bigger than Earth, with tight orbits that took them much closer to their host stars. In multi-planet systems, these orbits tended to be much closer together than they are in our solar system. For instance, the star known as Kepler-11 has six planets closer to it than Venus is to the sun.
Why does our solar system look so different? Astrophysicists Konstantin Batygin of Caltech and Greg Laughlin of UC Santa Cruz summed it up in one word: Jupiter.
Here’s what could have happened, according to their models:
In Solar System 1.0, the region closest to the sun was occupied by numerous planets with masses several times bigger than that of Earth. There were also planetesimals, “planetary building blocks” that formed within the first million years after the birth of the sun, Batygin and Laughlin wrote.
This is how things might have stayed if the young Jupiter had stayed put at its initial orbit, between 3 and 10 astronomical units away from the sun. (An astronomical unit, or AU, is the distance between the Earth and the sun. Today, Jupiter’s orbit ranges between 5 and 5.5 AUs from the sun.)
But Jupiter was restless, according to a scenario known as the “Grand Tack.” In this version of events, Jupiter was swept up by the currents of gas that surrounded the young sun and drifted toward the center of the solar system.
Jupiter, however, was too big to travel solo. All manner of smaller objects would have been dragged along too. With so many bodies in motion, there would have been a lot of crashes.
The result was “a collisional cascade that grinds down the planetesimal population to smaller sizes,” the astrophysicists wrote. For the most part, these planetary crumbs were swept toward the sun and ultimately destroyed, like disintegrating satellites falling back to Earth.
The planetesimals wouldn’t have been Jupiter’s only victims. Assuming the early solar system resembled the planetary systems spied by Kepler and other telescopes, there would have been “a similar population of first-generation planets,” the pair wrote. “If such planets formed, however, they were destroyed.”
Jupiter probably got about as close to the sun as Mars is today before reversing course, pulled away by the gravity of the newly formed Saturn. That would have ended the chaos in the inner solar system, allowing Earth and the other rocky planets to form from the debris that remained.
“This scenario provides a natural explanation for why the inner Solar System bears scant resemblance to the ubiquitous multi-planet systems” discovered by Kepler and other survey efforts, Batygin and Laughlin wrote.
Although their models show that this is what might have happened, they don’t prove that it actually did. But there may be a way to get closer to the truth.
The scientists’ equations suggest that if a star is orbited by a cluster of close-in planets, there won’t be a larger, farther-out planet in the same system. As astronomers find more exoplanetary systems, they can see whether this prediction holds up.
Also, if far-away solar systems are experiencing a similar series of events, telescopes ought to be able to detect the extra heat thrown off by all of the planetesimal collisions, they added.
Sadly for those hoping to find life on other planets, the pair’s calculations also imply that most Earth-sized planets are lacking in water and other essential compounds that can exist in liquid or solid form. As a result, they would be “uninhabitable,” they wrote.
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| March 9 Rosetta was 45 miles from Comet 67P/C-G when it photographed the comet’s head ringed with a halo of gas and dust. These jets extend from active areas of the comet’s surface and will become much more prominent over the next few months as the comet approaches the sun. |
Excerpt from dailytimesgazette.com
Astronomers have been on a mission to tail a slow moving comet in the outer space. Their mission started early last 2014, and they are getting better observations than they thought they would.
The comet, Comet 67P, would take 12.4 hours to complete one rotation in the circular path it’s moving in. Controllers of Rosetta are noticing that the icy ball approximately a second every day before it completes a rotation. The flight director of Rosetta – Andrea Accomazzo, said that, “The gas jets coming out of the comet, are acting like thrusters and are slowing down the comet.”
During the Royal Aeronautical Society in London earlier this week, the European Space Agency officially revealed some juicy details on how their team learned to maneuver Rosetta to fly precisely around the massive astral body. Comet 67P is said to weigh 10-billion tons with 4-km size in width.
The controllers and navigators use the landmark-method on the comet to understand its rotation. The team is moving around the outer space relying only on the information provided by the model. Both the model and information guides them in accurately projecting the trajectory of the satellite in the best position.
As they were trying out the model, the ESA team noticed that the landmarks were not following the usual track at the expected time.
During September 2014, the team were determined and very convinced that comet’s rotation period lengthen by 33 milliseconds per day. At present, the comet is approaching the Sun. As it does, it releases great volumes of gas and dust as a result of the so-called Spin-Down effect; further lengthening the rotation period to a second per day.
Accomazzo clarified that Comet 67P is not going to slow down in a slow motion. But its current speed allows them achieve the great magnitude of accuracy in navigating the spacecraft around the comet.
Rosetta made significant observations of the comet last December and January as it moves like an orbit within 30 km distance from the comet. However, this movement is no longer going to happen because Rosetta has retreated from the comet as the gas and dust are being released.
But it does them well as Accomazzo said that, “The aerodynamic effects are now more and more important. The jets are getting stronger and stronger… To give you an idea, these gases come out of the comet for a few kilometers and are moving at 800 meters per second. We definitely have to take this into account. We are a big spacecraft with 64 square meter s of solar panels. We’re like a big sail.”
The trackers were confused during the recent weeks because they have mistaken the dust particles for stars. It was due to the fact that the dusts in the atmosphere were moving around the comet.
Now, Rosetta is using its propulsion system to move in a hyperbolic orbital rotation around Comet 67P. It approaches the comet no closer than 60 to 70 km. With the slowdown of the comet, the ESA team is planning to fly closer.
They were estimating a flight as close as 20 km to get a better look at the surface of the comet and find their lost landing probe, Philae. They lost contact with the robotic probe since November 12 due to lost battery power only days after it successfully landed on the comet.
The slowdown gives them an opportunity to search for Philae. As it moves closer to the Sun, lighting conditions are definitely better than their previous runs. The controllers are now calling onto Philae using radio shout outs.
Philae is solar powered so the team hopes that enough solar energy falls on the panels awaking the probe. But one problem still persist, “The problem is that even if Philae hears Rosetta, it has to have enough charge to turn on its radio transmitter.”
The flight director is quite doubtful if Philae will be awakening. Andrea suggested, “I put it at 50-50, but I will be the happiest person in the world if it happens,”
Their mission achieved great progress and observation of a comet. The team is wishing for better things as the 67P slow down leaving them with more advantage
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| In this undated photo made available by Britain’s Channel 4 television of Oxford University genetics professor Bryan Sykes posing with a prepared DNA sample taken from hair from a Himalayan animal. |
Excerpt from theblaze.com
A new study that re-analyzed so-called “yeti” hair samples from previous research that had identified them as belonging to an “anomalous ursid” might have disappointing news for those who thought the findings last year meant a “bigfoot” of sorts was still out there. Yet, the author of the original findings stands by his claims.
Research published in the journal ZooKeys found that the hair samples said to be from Central Asia and the Himalayas belong to a known species in those regions.
“We have concluded that there is no reason to believe that the two samples came from anything other than brown bears,” the authors wrote in the study abstract.
After scientists analyzed more than 30 hair samples reportedly left behind by Bigfoot and other related beasts like Yeti, they found all of them came from more mundane animals like bears, wolves, cows and raccoons. Two samples were said to have been from an “anomalous ursid,” but new analysis suggests that the samples were from brown bears. (AP/Channel 4)
“We made this discovery that basically that fragment of DNA is not informative to tell apart two species of bears: the brown bear and [modern-day Alaskan] polar bear,” Gutierrez told Live Science.
At the time of his 2014 study, Sykes et al. wrote “[...] it is important to bear in mind that absence of evidence is not evidence of absence and this survey cannot refute the existence of anomalous primates, neither has it found any evidence in support. […] The techniques described here put an end to decades of ambiguity about species identification of anomalous primate samples and set a rigorous standard against which to judge any future claims.”
And Sykes still holds his ground, despite the more recent findings.
“What mattered most to us was that these two hairs were definitely not from unknown primates,” Sykes told Live Science in light of the recent research. “The explanation by Gutierrez and [Ronald] Pine might be right, or it might not be.”
To NBC News, Sykes said that Gutierrez’ findings are “entirely statistical.”
“The only way forward, as I have repeatedly said, is to find a living bear that matches the 12S RNA and study fresh material from it,” he continued. “Which involves getting off your butt, not an activity I usually associate with desk-bound molecular taxonomists.”
Daniel Loxton, an editor for Junior Skeptic, which is produced by the Skeptics Society, told Live Science that people will continue to believe in and seek out yetis, bigfoots and the like, because they are”fascinated by monsters, and they’re fascinated by mysteries in general.”
Blake Smith, in a blog post for the Skeptics Society laid out the whole saga involving Sykes research and the more recent analysis by Guiterrez. Smith ultimately concluded that he’s “still convinced that Yeti and Bigfoot are not to be found in the forests and mountains of the Earth, but in the minds of people.”
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| Astronomers in Brazil have discovered a cluster of stars forming at the edge of the Milky Way, according to a press release from the Royal Astronomical Society. |
Excerpt from news.discovery.com
This is unusual because it was believed that stars generally take form closer to the center of our spiral-shaped galaxy, rather than from its swirling, spiral arms, which are thousands of light-years away. These two clusters of stars — named Camargo 438 and 439 — were seen in a cloud at the galaxy’s outskirts.
Denilso Camargo, an astronomer at the Federal University of Rio Grande do Sul in Porto Alegre, Brazil, led a team that analyzed data from NASA’s orbiting Wide-Field Infrared Survey Explorer (WISE) observatory. They zeroed in on dense clumps of gas in so-called giant molecular clouds(GMCs) that are known to generate stars. GMCs are mainly located in the inner part of the galactic disc.
The new star clusters lie about 16,000 light-years away from the main disk of the Milky Way galaxy. How did they form there? The scientists aren’t yet sure but Camargo theorizes that one of two scenarios could have led to the stars’ formation.
In the first scenario, called the “chimney model,” supernovas could have flung the gas and dust that formed the cloud out of the Milky Way. Another explanation is the material could have drifted in from outside the galaxy.
“Our work shows that the space around the Galaxy is a lot less empty that we thought,” said Camargo. “The new clusters of stars are truly exotic.”
Camargo’s team published their results in the journal Monthly
Excerpt from csmonitor.com
Thanks to a phenomenon known as gravitational lensing, the Hubble Space Telescope has captured four images of the same supernova explosion.
For the first time, a cosmic magnifying glass has allowed scientists to see the same star explosion four times, possibly offering a revealing glimpse into these explosive stellar deaths and the nature of the accelerating universe.
Astronomers using the Hubble Space Telescope have captured four images of a supernova explosion in deep space thanks to a galaxy located between Earth and the massive star explosion. You can see how Hubble saw the supernova in this NASA video. The galaxy cluster warped the fabric of space and time around it — like a bowling ball placed on a bed sheet — allowing scientists to see the supernova in four images.
"It was predicted 50 years ago that a supernova could be gravitationally lensed like this, but it's taken a long time for someone to find an example," lead study author Patrick Kelly, an astronomer at the University of California, Berkeley told Space.com. "It's fun to have been able to find the first one."
The supernova, which was discovered on Nov. 11, 2014, is located about 9.3 billion light-years away from Earth, near the edge of the observable universe. The researchers have named the distant supernova SN Refsdal in honor of the late Norwegian astrophysicist Sjur Refsdal, a pioneer of gravitational lensing studies. Due to gravitational lensing, "the supernova appears 20 times brighter than its normal brightness," study co-author Jens Hjorth, head of the Dark Cosmology Centre at the Niels Bohr Institute at the University of Copenhagen, said in a statement.
The lensing galaxy, which is about 5 billion light-years from Earth, is part of a large cluster of galaxies known MACS J1149.6+2223. In 2009, astronomers discovered that this cluster was the source of the largest known image of a spiral galaxy ever seen through a gravitational lens.
The four images of the supernova each appeared separately over the course of a few weeks. This is because light can take various paths around and through a gravitational lens, arriving at Earth at different times.
Using gravity as a lens
Gravity is created when matter warps the fabric of reality. The greater the mass of an object, the more space-time curves around that object and the stronger its gravitational pull, the discovery enshrined in Einstein's theory of general relativity, which celebrates its centennial this year.
As a result, gravity can also bend light like a lens, meaning objects see n behind powerful gravitational fields, such as those of massive galaxies, are magnified. Gravitational lensing was first discovered in 1979, and today gravitational lenses can help astronomers see features otherwise too distant and faint to detect with even the largest telescopes.
"These gravitational lenses are like a natural magnifying glass. It's like having a much bigger telescope," Kelly said in a statement. "We can get magnifications of up to 100 times by looking through these galaxy clusters."
When light is far from a gravitationally lensing mass, or if the gravitationally lensing mass is not especially large, only "weak lensing" occurs, barely distorting the light. However, when the light comes from almost exactly behind the gravitationally lensing mass, "strong lensing" can happen.
When a strongly lensed object occupies a large patch of space — for instance, if it's a galaxy — it can get smeared into an "Einstein ring" surrounding a gravitationally lensing mass. However, strong lensing of small, pointlike items — for instance, super-bright objects known as quasars — often produces multiple images surrounding the gravitationally lensing mass, resulting in a so-called "Einstein cross."
The observations of SN Refsdal mark the first time astronomers on Earth have witnessed strong lensing of a supernova, with four images of an exploding star arrayed as an Einstein cross.
An expanding universe
These new findings could help scientists measure the accelerating rate at which the universe is expanding, researchers say.
A computer model of the lensing cluster suggests the scientists missed chances to see the lensed supernova 50 and 10 years ago. However, the model also suggests more images of the explosion will repeat again within the next 10 years.
The timing of when all these images of the supernova arrive depends on the gravitational pull of the matter generating the gravitational lens. So, by measuring those times, the researchers hope to map how visible normal matter and invisible dark matter is distributed in the lensing galaxy.
Dark matter is currently one of the greatest mysteries in science, a poorly understood substance thought to make up five-sixths of all matter in the universe. A better understanding of how dark matter is behaving in this gravitationally lensing cluster might help shed light on the material's nature, Kelly said.
Analyzing when the images arrive could also help scientists pinpoint the rate at which the universe is expanding. Although there are already several ways to measure the cosmic expansion rate, "there has been a lot of heated debate between different methods, so it'd be interesting to see how this new technique might affect the area," Kelly said. "It's always nice to have completely independent measurements of the same quantity."
The scientists detailed their findings in the March 6 issue of the journal Science.
The background image in this composite shows the Hubble Space Telescope image of the region known as the Hubble Deep Field South. The boxes show distant galaxies that were invisible to Hubble.Excerpt from huffingtonpost.comAlong with Earthrise ...
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