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  • richardmitnick 6:57 am on September 3, 2018 Permalink | Reply
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    From The Atlantic via WIRED: “China Built the World’s Largest Telescope. Then Came the Tourists” 

    Atlantic Magazine

    The Atlantic Magazine

    via

    Wired logo

    WIRED

    08.26.18
    Sarah Scoles

    Thousands of people moved[?*] to let China build and protect the world’s largest telescope. And then the government drew in orders of magnitude more tourists, potentially undercutting its own science in an attempt to promote it.

    FAST radio telescope, with phase arrays from Australia [https://sciencesprings.wordpress.com/2017/12/18/from-csiroscope-our-top-telescope-tech-travels-fast/] located in the Dawodang depression in Pingtang County, Guizhou Province, south China

    “I hope we go inside this golf ball,” Sabrina Stierwalt joked as she and a group of other radio astronomers approached what did, in fact, appear to be a giant golf ball in the middle of China’s new Pingtang Astronomy Town.

    Stierwalt was a little drunk, a lot full, even more tired. The nighttime scene felt surreal. But then again, even a sober, well-rested person might struggle to make sense of this cosmos-themed, touristy confection of a metropolis.

    On the group’s walk around town that night, they seemed to traverse the ever-expanding universe. Light from a Saturn-shaped lamp crested and receded, its rings locked into support pillars that appeared to make it levitate. Stierwalt stepped onto a sidewalk, and its panels lit up beneath her feet, leaving a trail of lights behind her like the tail of a meteor. Someone had even brought constellations down to Earth, linking together lights in the ground to match the patterns in the sky.

    1
    The tourist town, about 10 miles from the telescope, lights up at night. Credit Intentionally Withheld

    The day before, Stierwalt had traveled from Southern California to Pingtang Astronomy Town for a conference hosted by scientists from the world’s largest telescope. It was a new designation: China’s Five-Hundred-Meter Aperture Spherical Radio Telescope, or FAST, had been completed just a year before, in September 2016. Wandering, tipsy, around this shrine to the stars, the 40 or so other foreign astronomers had come to China to collaborate on the superlative-snatching instrument.

    For now, though, they wouldn’t get to see the telescope itself, nestled in a natural enclosure called a karst depression about 10 miles away. First things first: the golf ball.

    As the group got closer, they saw a red carpet unrolled into the entrance of the giant white orb, guarded by iridescent dragons on an inflatable arch. Inside, they buckled up in rows of molded yellow plastic chairs. The lights dimmed. It was an IMAX movie—a cartoon, with an animated narrator. Not the likeness of a person but … what was it? A soup bowl?

    No, Stierwalt realized. It was a clip-art version of the gargantuan telescope itself. Small cartoon FAST flew around big cartoon FAST, describing the monumental feat of engineering just over yonder: a giant geodesic dome shaped out of 4,450 triangular panels, above which receivers collect radio waves from astronomical objects.

    FAST’s dish, nestled into a depression, is made of thousands of triangular panels. located in the Dawodang depression in Pingtang County, Guizhou Province, south China located in the Dawodang depression in Pingtang County, Guizhou Province, south China VCGGetty Images

    China spent $180 million to create the telescope, which officials have repeatedly said will make the country the global leader in radio astronomy. But the local government also spent several times that on this nearby Astronomy Town—hotels, housing, a vineyard, a museum, a playground, classy restaurants, all those themed light fixtures. The government hopes that promoting their scope in this way will encourage tourists and new residents to gravitate to the historically poor Guizhou province.

    It is, in some sense, an experiment into whether this type of science and economic development can coexist. Which is strange, because normally, they purposefully don’t.

    The point of radio telescopes is to sense radio waves from space—gas clouds, galaxies, quasars. By the time those celestial objects’ emissions reach Earth, they’ve dimmed to near-nothingness, so astronomers build these gigantic dishes to pick up the faint signals. But their size makes them particularly sensitive to all radio waves, including those from cell phones, satellites, radar systems, spark plugs, microwaves, Wi-Fi, short circuits, and basically anything else that uses electricity or communicates. Protection against radio-frequency interference, or RFI, is why scientists put their radio telescopes in remote locations: the mountains of West Virginia, the deserts of Chile, the way-outback of Australia.

    FAST’s site used to be remote like that. The country even forcibly relocated thousands of villagers who lived nearby, so their modern trappings wouldn’t interfere with the new prized instrument.

    But then, paradoxically, the government built—just a few miles from the displaced villagers’ demolished houses—this astronomy town. It also plans to increase the permanent population by hundreds of thousands. That’s a lot of cell phones, each of which persistently emits radio waves with around 1 watt of power.

    By the time certain deep-space emissions reach Earth, their power often comes with 24+ zeroes in front: 0.0000000000000000000000001 watts.

    FAST has been in the making for a long time. In the early 2000s, China angled to host the Square Kilometre Array, a collection of coordinated radio antennas whose dishes would be scattered over thousands of miles. But in 2006, the international SKA committee dismissed China, and then chose to set up its distributed mondo-telescope in South Africa and Australia instead.

    Undeterred, Chinese astronomers set out to build their own powerful instrument.

    In 2007, China’s National Development and Reform Commission allocated $90 million for the project, with $90 million more streaming in from other agencies. Four years later, construction began in one of China’s poorest regions, in the karst hills of the southwestern part of the country. They do things fast in China: The team finished the telescope in just five years. In September 2016, FAST received its “first light,” from a pulsar 1,351 light-years away, during its official opening.

    A year later, Stierwalt and the other visiting scientists arrived in Pingtang, and after an evening of touring Astronomy Town, they got down to business.

    See, FAST’s opening had been more ceremony than science (the commissioning phase is officially scheduled to end by September 2019). It was still far from fully operational—engineers are still trying to perfect, for instance, the motors that push and pull its surface into shape, allowing it to point and focus correctly. And the relatively new crop of radio astronomers running the telescope were hungry for advice about how to run such a massive research instrument.

    The visiting astronomers had worked with telescopes that have contributed to understanding of hydrogen emissions, pulsars, powerful bursts, and distant galaxies. But they weren’t just subject experts: Many were logistical wizards, having worked on multiple instruments and large surveys, and with substantial and dispersed teams. Stierwalt studies interacting dwarf galaxies, and while she’s a staff scientist at Caltech/IPAC, she uses telescopes all over. “Each gives a different piece of the puzzle,” she says. Optical telescopes show the stars. Infrared instruments reveal dust and older stars. X-ray observatories pick out black holes. And single-dish radio telescopes like FAST see the bigger picture: They can map out the gas inside of and surrounding galaxies.

    So at the Radio Astronomy Conference, Stierwalt and the other visitors shared how FAST could benefit from their instruments, and vice versa, and talked about how to run big projects. That work had begun even before the participants arrived. “Prior to the meeting, I traveled extensively all over the world to personally meet with the leaders of previous large surveys,” says Marko Krčo, a research fellow who’s been working for the Chinese Academy of Sciences since the summer of 2016.

    He asked the meeting’s speakers, some of those same leaders, to talk about what had gone wrong in their own surveys, and how the interpersonal end had functioned. “How did you organize yourselves?” he says. “How did you work together? How did you communicate?”

    That kind of feedback would be especially important for FAST to accomplish one of its first, appropriately lofty goals: helping astronomers collect signals from many sides of the universe, all at once. They’d call it the Commensal Radio Astronomy FAST Survey, or CRAFTS.

    3
    Above the dish, engineers have suspended instruments that collect cosmic radio waves. Feature China/Barcroft Media/Getty Images

    Most radio astronomical surveys have a single job: Map gas. Find pulsars. Discover galaxies. They do that by collecting signals in a receiver suspended over the dish of a radio telescope, engineered to capture a certain range of frequencies from the cosmos. Normally, the different astronomer factions don’t use that receiver at the same time, because they each take their data differently. But CRAFTS aims to be the first survey that simultaneously collects data for such a broad spectrum of scientists—without having to pause to reconfigure its single receiver.

    CRAFTS has a receiver that looks for signals from 1.04 gigahertz to 1.45 gigahertz, about 10 times higher than your FM radio. Within that range, as part of CRAFTS, scientists could simultaneously look for gas inside and beyond the galaxy, scan for pulsars, watch for mysterious “fast radio bursts,” make detailed maps, and maybe even search for ET. “That sounds straightforward,” says Stierwalt. “Point the telescope. Collect the data. Mine the data.”

    4
    Engineers from FAST and the Australian science agency install the telescope’s CRAFTS receiver. Marko Krčo

    But it’s not easy. Pulsar astronomers want quicktime samples at a wide range of frequencies; hydrogen studiers, meanwhile, don’t need data chunks as often, but they care deeply about the granular frequency details. On top of that, each group adjusts the observations, calibrating them, kind of like you’d make sure your speedometer reads 45 mph when you’re going 45. And they use different kinds of adjustments.

    When we spoke, Krčo had just returned from a trip to Green Bank, where he was testing whether they could set everyone’s speedometer correctly. “I think it will be one of the big sort of legacies of FAST,” says Krčo. And it’s especially important since the National Science Foundation has recently cratered funding to both Arecibo and Green Bank observatories, the United States’ most significant single-dish radio telescopes.


    NAIC Arecibo Observatory, previously the largest radio telescope in the world operated by University of Central Florida, Yang Enterprises and UMET, Altitude 497 m (1,631 ft)

    Green Bank does have financial support, $2 million per year for five years from Yuri Milner’s Breaktrhough Listen Project.

    Breakthrough Listen Project

    1

    Lick Automated Planet Finder telescope, Mount Hamilton, CA, USA



    GBO radio telescope, Green Bank, West Virginia, USA


    CSIRO/Parkes Observatory, located 20 kilometres north of the town of Parkes, New South Wales, Australia

    While they remain open, they have to seek private project money, meaning chunks of time are no longer available for astronomers’ proposals. Adding hours, on a different continent, helps everybody.

    At the end of the conference in Pingtang County, Krčo and his colleagues presented a concrete plan for CRAFTS, giving all the visitors a chance to approve the proposed design. “Each group could raise any red flags, if necessary, regarding their individual science goals or suggest modifications,” says Krčo.

    In addition to the CRAFTS receiver, Krčo says they’ll add six more, sensitive to different frequencies. Together, they will detect radio waves from 70 megahertz to 3 gigahertz. He says they’ll find thousands of new pulsars (as of July 2018, they had already found more than 40), and do detailed studies of hydrogen inside the galaxy and in the wider universe, among numerous other worthy scientific goals.

    “There’s just a hell of a lot of work to do to get there,” says Krčo. “But we’re doing it.”

    For FAST to fulfill its potential, though, Krčo and his colleagues won’t just have to solve engineering problems: They’ll also have to deal with the problems that engineering created.

    During the four-day Radio Astronomy Forum, Stierwalt and the other astronomers did, finally, get to see the actual telescope, taking a bus up a tight, tortuous road through the karst between town and telescope.

    As soon as they arrived on site, they were instructed to shut down their phones to protect the instrument from the radio frequency interference. But not even these astronomers, who want pristine FAST data for themselves, could resist pressing that capture button. “Our sweet, sweet tour guide continually reminded us to please turn off our phones,” says Stierwalt, “but we all kept taking pictures and sneaking them out because no one really seemed to care.” Come on: It’s the world’s largest telescope.

    Maybe their minder stayed lax because a burst here or there wouldn’t make much of a difference in those early days. The number of regular tourists allowed at the site all day is capped at 3,000, to limit RFI, and they have to put their phones in lockers before they go see the dish. Krčo says the site bumps up against the visitor limit most days.

    But tourism and development are complicated for a sensitive scientific instrument. Within three miles of the telescope, the government passed legislation establishing a “radio-quiet zone,” where RFI-emitting devices are severely restricted. No one (not cellular providers or radio broadcasters) can get a transmitting license, and people entering the facility itself will have their electronics confiscated. “No one lives inside the zone, and the area is not open to the general public,” says Krčo, although some with commercial interests, like local farmers, can enter the zone with special permission. The government relocated villagers who lived within that protected area with promises of repayment in cash, housing, and jobs in tourism and FAST support services. (Though a 2016 report in Agence France-Presse revealed that up to 500 relocated families were suing the Pingtang government, alleging “land grabs without compensation, forced demolitions and unlawful detentions.”)

    The country’s Civil Aviation Administration has also adjusted air travel, setting up two restricted flight zones near the scope, canceling two routes, and adding or adjusting three others. “We can still see some RFI from aircraft navigational beacons,” says Krčo. “It’s much less, though, compared to what it’d look like without the adjusted air routes. It’d be impossible to fully clear a large enough air space to create a completely quiet sky.”

    None of the invisible boundaries, after all, function like force fields. RFI that originates from beyond can pass right on through. At least at the five-star tourist hotel, around 10 miles away, there’s Wi-Fi. The tour center, says an American pulsar astronomer, has a direct line of sight to the telescope.

    When Krčo first arrived on the job, he stayed in the astronomy town. “Every morning, we were counting all the new buildings springing up overnight,” Krčo says. “It would be half a dozen.”

    One day, he woke up to a new five-story structure out his window. Couldn’t be, he thought. But he checked a picture he’d taken the day before, and, sure enough, there had been no building in that spot.

    The corn close to town was covered in construction dust. “I’ve never seen anything like that in my whole life,” says Krčo. Today, though, the corn is gone, covered instead in hotels, museums, and shopping centers.

    5
    Before FAST, few large structures existed in this part of China. Feature China/Barcroft Media/Getty Images

    6
    Now, they abound. Liu Xu/Xinhua/Getty Images

    At a press conference in March 2017, Guizhou’s governor declared that the province would build 10,000 kilometers of new highway by 2020, in addition to completing 17 airports and 4,000 kilometers of high-speed train lines. That’s partly to accommodate the hundreds of thousands of people the province expects to relocate here permanently, as well as the tourists. While just those 3,000 people per day will get to visit the telescope itself, there’s no cap on how many can sojourn in Astronomy Town; the deputy director of Guizhou’s reform and development commission, according to China Daily, said it would be “a main astronomical tourism zone worldwide.” “The town has grown incredibly over the last couple of years due to tourism development,” says Krčo. “This has impacted our RFI environment, but not yet to a point where it is unmanageable.”

    Krčo says that geography protects FAST against much of that human interference. “There are a great many mountains between the telescope and the town,” says Krčo. The land blocks the waves, which you’ve seen yourself if you’ve ever tried to pick up NPR in a canyon. But even though the waves can’t go directly into the telescope, Krčo says the team still sees their echoes, reflections beamed down from the atmosphere.

    “People at the visitors’ center have been using cameras and whatnot, and we can see the RFI from that,” he said last November (enforcement seems to have ramped up since then). “During the daytime,” he adds, “our RFI is much worse than nighttime,” largely due to engineers working onsite (that should improve once commissioning is over). But the tourist traps aren’t run and weren’t developed by FAST staff but by various governmental arms—so FAST, really, has no control over what they do.

    The global radio astronomy community has concerns. “I’m absolutely sure that if people are going to bring their toys, then there’s going to be RFI,” says Carla Beaudet, an RFI engineer at Green Bank Observatory, who spends her career trying to help humans see the radio sky despite themselves. Green Bank itself sits in the middle of a strict radio protection zone with a radius of 10 miles, in which there’s no Wi-Fi or even microwaves.

    There are other ways of dealing with RFI—and Krčo says FAST has a permanent team of engineers dedicated to dealing with interference. One solution, which can pick up the strongest contamination, is a small antenna mounted to one of FAST’s support towers. “The idea is that it will observe the same RFI as the big dish,” says Krčo. “Then, in principle, we can remove the RFI from the data in real time.”

    At other telescopes, astronomers are developing machine-learning algorithms that could identify, extract, and compensate for dirty data. All telescopes, after all, have human contamination, even the ones without malls next door. You can’t stop a communications satellite from passing overhead, or a radar beam from bouncing the wrong way across the mountains. And while you can decide not to build a tourist town in the first place, you probably can’t stop a tidal wave of construction once it’s crested.

    In their free evenings at the Radio Astronomy Forum, Stierwalt and the other astronomers wandered through the development. Across from their luxury hotel, workers were constructing a huge mall. It was just scaffolding then, but sparks flew from tools every night. “So the joke was, ‘I wonder if we’ll be able to go shopping at the mall by the end of our trip,’” says Stierwalt.

    At the end of the conference, Stierwalt rode a bus back to the airport, awed by what she’d seen. The karst hills, dipping and rising out the window, looked like those in Puerto Rico, where she had used the 300-meter Arecibo telescope for weeks at a time during her graduate research.

    When she tried to check in for her flight, she didn’t know where to go, what to do. An agent wrote her passport number down wrong.

    A young Chinese man, an astronomer, saw her struggle and approached her. “I’m on your flight,” he said, “and I’ll make sure you get on it.”

    In line after line, they started talking about other things—life, science. “I was describing the astronomy landscape for me,” she says. Never enough jobs, never enough research money, necessary competition with your friends. “For him, it’s very different.”

    He lives in a country that wants to accrete a community of radio astronomers, not winnow one down. A country that wants to support (and promote) ambitious telescopes, rather than defund the ones it has. China isn’t just trying to build a tourist economy around its telescope—it’s also trying to build a scientific culture around radio astronomy.

    That latter part seems like a safe bet. But the first is still uncertain. So is how the tourist economy will affect—for better or worse—FAST’s scientific payoff. “Much like their CRAFTS survey is trying to make everyone happy—all the different kinds of radio astronomers—this will be a true test of ‘Can you make everyone happy?’” says Stierwalt. “Can you make a prosperous astronomy town right next to a telescope that doesn’t want you to be using your phone or your microwave?”

    Right now, nobody knows. But if the speed of everything else in Guizhou is any indication, we’ll all find out fast.

    [* I had previously read, which I cannot any longer back up, that FAST was built in a fortunately found an empty natural bowl in the land. If anyone can correct me, please do]

    See the full article here .

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  • richardmitnick 12:52 pm on July 16, 2018 Permalink | Reply
    Tags: , , , , , , GBO -Green Bank Observatory, New images from a super-telescope, ,   

    From Netherlands Institute for Radio Astronomy: “New images from a super-telescope” 

    ASTRON bloc

    From Netherlands Institute for Radio Astronomy

    1

    New images from a super-telescope bring astronomers a step closer to understanding dark matter.

    Astronomers using a global network of radio telescopes have produced one of the sharpest astronomical images ever. The resulting image demonstrates that dark matter is distributed unevenly across a distant galaxy.

    The image was created by combining data from a global radio telescope network, comprised of the European VLBI Network, and the Very Long Baseline Array and Green Bank Telescope in the United States, in an effort to address some of the fundamental questions about dark matter. The international team of astronomers aim to determine how much dark matter is present in galaxies and how it is distributed. According to current theories, a galaxy, such as our Milky Way, should have thousands of dwarf galaxies orbiting around it, yet to date only approximately 100 have been found.

    European VLBI

    NRAO/VLBA

    Green Bank Radio Telescope, West Virginia, USA

    “It has been suggested that these dwarf galaxies could be dark matter dominated and, therefore, highly difficult to observe. However, throughout the distant Universe, we can discover the presence of these small mass structures only by using the gravitational lensing effect,” explains Cristiana Spingola, lead author on the paper, from the Kapteyn Astronomical Institute, Groningen.

    Gravitational lensing allows astronomers to observe incredibly distant radio sources that cannot be directly detected.

    Gravitational Lensing NASA/ESA

    By observing how the radio emission from the distant source is bent by the gravitational field of a massive object – the lens – located between the source and the Earth, it is possible to determine information about both the distant source and the lens. In this study the researchers used the radio source MG J0751+2716, at such great a distance that it has taken the light 11.7 billion years to reach the Earth. This object is comprised of a black hole with a powerful ejection of material, known as a jet. The lens consists of a group of galaxies located at a look-back time of 3.9 billion years from Earth.

    In the study, the astronomers were able to determine the distance, brightness and projected size of the radio source, together with the composition of dark matter across the lens, which appeared clumpy and uneven.

    “For the first time we were able to observe large gravitationally lensed arcs on extremely small angular scales. The background source – the black hole with radio jets – is distorted into these arcs on the image because of the gravitational effect of the foreground galaxies (the lens). It is a rare possibility to get such an extended arc.” Spingola added, “the unprecedented detail of these extended gravitational arcs allowed us to infer with high precision the distribution of the matter of the galaxy acting as a lens.”

    It is only possible to obtain such high-resolution data by coordinating multiple telescopes to observe the same radio source simultaneously. In this case, 24 radio antennas from across the globe were connected using a technique called Very Long Baseline Interferometry (VLBI). Data from all the telescopes was collated in a process known as correlation, at a super computer housed at the Joint Institute for VLBI ERIC in Dwingeloo, the Netherlands.

    To better understand the properties for dark matter, the team are now applying sophisticated numerical algorithms to quantify the nature of the clumpy dark matter. But, they are also on the hunt for more extended gravitational arcs just like this.

    “There are only a limited number of gravitational lenses suitable for this study, and while we have started this search using the European VLBI Network and the Very Long Baseline Array we expect that there will be more giant radio arcs in the future,” explained John McKean, project lead from the Netherlands Institute for Radio Astronomy (ASTRON) and the Kapteyn Astronomical Institute.

    This study was led by John McKean from the Kapteyn Astronomical Institute, University of Groningen and the Netherlands Institute for Radio Astronomy (ASTRON), Dwingeloo on behalf of the international research team SHARP (Strong Lensing at High Angular Resolution Project) led by Chris Fassnacht (University of California, Davis), and also including Matt Auger (University of Cambridge), Leon Koopmans (University of Groningen), David Lagattuta (University of Lyon) and Simona Vegetti (Max Planck Institute for Astrophysics). Their findings can be found in Issue 4, Volume 478 of the Monthly Notices of the Royal Astronomical Society, published by Oxford University Press.

    See the full article here .

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    LOFAR is a radio telescope composed of an international network of antenna stations and is designed to observe the universe at frequencies between 10 and 250 MHz. Operated by ASTRON, the network includes stations in the Netherlands, Germany, Sweden, the U.K., France, Poland and Ireland.
    ASTRON-Westerbork Synthesis Radio Telescope
    Westerbork Synthesis Radio Telescope (WSRT)

    ASTRON was founded in 1949, as the Foundation for Radio radiation from the Sun and Milky Way (SRZM). Its original charge was to develop and operate radio telescopes, the first being systems using surplus wartime radar dishes. The organisation has grown from twenty employees in the early 1960’s to about 180 staff members today.

     
  • richardmitnick 2:07 pm on July 12, 2018 Permalink | Reply
    Tags: Binary asteroid 2017 YE5, GBO -Green Bank Observatory, Goldstone Solar System Radar, ,   

    From JPL Caltech: “Observatories Team Up to Reveal Rare Double Asteroid” 

    NASA JPL Banner

    From JPL-Caltech

    July 12, 2018

    Calla Cofield
    Jet Propulsion Laboratory, Pasadena, Calif.
    818-393-1821
    Calla.e.cofield@jpl.nasa.gov

    JoAnna Wendel
    NASA Headquarters, Washington
    202-358-1003
    joanna.r.wendel@nasa.gov

    1
    Artist’s concept of what binary asteroid 2017 YE5 might look like. The two objects showed striking differences in radar reflectivity, which could indicate that they have different surface properties.Credit: NASA/JPL-Caltech

    2
    Observatories Team Up to Reveal Rare Double Asteroid
    Artist’s illustration of the trajectory of asteroid 2017 YE5 through the solar system. At its closest approach to Earth, the asteroid came to within 16 times the distance between Earth and the moon.Credit: NASA/JPL-Caltech

    3
    Observatories Team Up to Reveal Rare Double Asteroid
    This optical composite image shows asteroid 2017 YE5, taken on June 30, 2018, by the Cadi Ayyad University Morocco Oukaimeden Sky Survey, one of the first surveys to identify 2017 YE5 in December 2017. Credit: Cadi Ayyad University Morocco Oukaimeden Sky Survey

    New observations by three of the world’s largest radio telescopes have revealed that an asteroid discovered last year is actually two objects, each about 3,000 feet (900 meters) in size, orbiting each other.


    Three of the world’s largest radio telescopes team up to show a rare double asteroid. 2017 YE5 is only the fourth binary near-Earth asteroid ever observed in which the two bodies are roughly the same size, and not touching. This video shows radar images of the pair gathered by Goldstone Solar System Radar, Arecibo Observatory and Green Bank Observatory.

    NASA DSCC Goldstone Antenna California in the Mojave Desert, USA

    NAIC Arecibo Observatory operated by University of Central Florida, Yang Enterprises and UMET, Altitude 497 m (1,631 ft)

    Green Bank Radio Telescope, West Virginia, USA

    Near-Earth asteroid 2017 YE5 was discovered with observations provided by the Morocco Oukaimeden Sky Survey on Dec. 21, 2017, but no details about the asteroid’s physical properties were known until the end of June. This is only the fourth “equal mass” binary near-Earth asteroid ever detected, consisting of two objects nearly identical in size, orbiting each other. The new observations provide the most detailed images ever obtained of this type of binary asteroid.

    On June 21, the asteroid 2017 YE5 made its closest approach to Earth for at least the next 170 years, coming to within 3.7 million miles (6 million kilometers) of Earth, or about 16 times the distance between Earth and the Moon. On June 21 and 22, observations by NASA’s Goldstone Solar System Radar (GSSR) in California showed the first signs that 2017 YE5 could be a binary system. The observations revealed two distinct lobes, but the asteroid’s orientation was such that scientists could not see if the two bodies were separate or joined. Eventually, the two objects rotated to expose a distinct gap between them.

    Scientists at the Arecibo Observatory in Puerto Rico had already planned to observe 2017 YE5, and they were alerted by their colleagues at Goldstone of the asteroid’s unique properties. On June 24, the scientists teamed up with researchers at the Green Bank Observatory (GBO) in West Virginia and used the two observatories together in a bi-static radar configuration (in which Arecibo transmits the radar signal and Green Bank receives the return signal). Together, they were able to confirm that 2017 YE5 consists of two separated objects. By June 26, both Goldstone and Arecibo had independently confirmed the asteroid’s binary nature.

    The new observations obtained between June 21 and 26 indicate that the two objects revolve around each other once every 20 to 24 hours. This was confirmed with visible-light observations of brightness variations by Brian Warner at the Center for Solar System Studies in Rancho Cucamonga, California.

    Radar imaging shows that the two objects are larger than their combined optical brightness originally suggested, indicating that the two rocks do not reflect as much sunlight as a typical rocky asteroid. 2017 YE5 is likely as dark as charcoal. The Goldstone images taken on June 21 also show a striking difference in the radar reflectivity of the two objects, a phenomenon not seen previously among more than 50 other binary asteroid systems studied by radar since 2000. (However, the majority of those binary asteroids consist of one large object and a much smaller satellite.) The reflectivity differences also appear in the Arecibo images and hint that the two objects may have different densities, compositions near their surfaces, or different surface roughnesses.

    Scientists estimate that among near-Earth asteroids larger than 650 feet (200 meters) in size, about 15 percent are binaries with one larger object and a much smaller satellite. Equal-mass binaries like 2017 YE5 are much rarer. Contact binaries, in which two similarly sized objects are in contact, are thought to make up another 15 percent of near-Earth asteroids larger than 650 feet (200 meters) in size.

    The discovery of the binary nature of 2017 YE5 provides scientists with an important opportunity to improve understanding of different types of binaries and to study the formation mechanisms between binaries and contact binaries, which may be related. Analysis of the combined radar and optical observations may allow scientists to estimate the densities of the 2017 YE5 objects, which will improve understanding of their composition and internal structure, and of how they formed.

    Study contributors

    The Goldstone observations were led by Marina Brozovi?, a radar scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California.

    Anne Virkki, Flaviane Venditti and Sean Marshall of the Arecibo Observatory and the University of Central Florida led the observations using the Arecibo Observatory.

    Patrick Taylor of the Universities Space Research Association (USRA), scientist at the Lunar and Planetary Institute, led the bi-static radar observations with GBO, home of the Green Bank Telescope (GBT), the world’s largest fully steerable radio telescope.

    The Arecibo, Goldstone and USRA planetary radar projects are funded through NASA’s Near-Earth Object Observations Program within the Planetary Defense Coordination Office (PDCO), which manages the Agency’s Planetary Defense Program. The Arecibo Observatory is a facility of the National Science Foundation operated under cooperative agreement by the University of Central Florida, Yang Enterprises, and Universidad Metropolitana. GBO is a facility of the National Science Foundation, operated under a cooperative agreement by Associated Universities, Inc.

    In addition to the resources NASA puts into understanding asteroids, the PDCO also partners with other U.S. government agencies, university-based astronomers, and space science institutes across the country, often with grants, interagency transfers and other contracts from NASA. They also collaborate with international space agencies and institutions that are working to track and better understand these smaller objects of the Solar System. In addition, NASA values the work of numerous highly skilled amateur astronomers, whose accurate observational data helps improve asteroid orbits after discovery.

    More information about asteroids and near-Earth objects is at these sites:

    https://cneos.jpl.nasa.gov

    https://www.jpl.nasa.gov/asteroidwatch

    See the full article here .


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    NASA JPL Campus

    Jet Propulsion Laboratory (JPL) is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. Although the facility has a Pasadena postal address, it is actually headquartered in the city of La Cañada Flintridge, on the northwest border of Pasadena. JPL is managed by the nearby California Institute of Technology (Caltech) for the National Aeronautics and Space Administration. The Laboratory’s primary function is the construction and operation of robotic planetary spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating NASA’s Deep Space Network.

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  • richardmitnick 1:45 pm on June 11, 2018 Permalink | Reply
    Tags: AME-anomalous microwave emission, , , ATCA-Australia Telescope Compact Array, , , Diamond Dust Shimmering around Distant Stars, GBO -Green Bank Observatory, Mysterious cosmic microwave “glow” emanating from several protoplanetary disks in our galaxy,   

    From Green Bank Observatory: Diamond Dust Shimmering around Distant Stars: Nanoscale gemstones source of mysterious cosmic microwave light 

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    Green Bank Radio Telescope, West Virginia, USA
    Green Bank Radio Telescope, West Virginia, USA

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    From Green Bank Observatory

    Press Release

    11 June 2018
    Paul Vosteen
    Media Specialist; Education & Public Outreach
    Green Bank Observatory
    +1.304.456.2212
    pvosteen@nrao.edu

    Some of the tiniest diamonds in the universe – bits of crystalline carbon hundreds of thousands of times smaller than a grain of sand – have been detected swirling around three infant star systems in the Milky Way. These microscopic gemstones are neither rare nor precious; they are, however, exciting for astronomers who identified them as the source of a mysterious cosmic microwave “glow” emanating from several protoplanetary disks in our galaxy.

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    Artist impression of nanoscale diamonds surrounding a young star in the Milky Way. Recent GBT and ATCA observations have identified the telltale radio signal of diamond dust around 3 such stars, suggesting they are a source of the so-called anomalous microwave emission. Credit: S. Dagnello, NRAO/AUI/NSF

    For decades, astronomers have puzzled over the exact source of a peculiar type of faint microwave light emanating from a number of regions across the Milky Way. Known as anomalous microwave emission (AME), this light comes from energy released by rapidly spinning nanoparticles – bits of matter so small that they defy detection by ordinary microscopes. (The period on an average printed page is approximately 500,000 nanometers across.)

    “Though we know that some type of particle is responsible for this microwave light, its precise source has been a puzzle since it was first detected nearly 20 years ago,” said Jane Greaves, an astronomer at Cardiff University in Wales and lead author on a paper announcing this result in Nature Astronomy.

    Until now, the most likely culprit for this microwave emission was thought to be a class of organic molecules known as polycyclic aromatic hydrocarbons (PAHs) – carbon-based molecules found throughout interstellar space and recognized by the distinct, yet faint infrared (IR) light they emit. Nanodiamonds — particularly hydrogenated nanodiamonds, those bristling with hydrogen-bearing molecules on their surfaces — also naturally emit in the infrared portion of the spectrum, but at a different wavelength.

    A series of observations with the National Science Foundation’s Green Bank Telescope (GBT) in West Virginia and the Australia Telescope Compact Array (ATCA) has — for the first time — homed in on three clear sources of AME light, the protoplanetary disks surrounding the young stars known as V892 Tau, HD 97048, and MWC 297. The GBT observed V892 Tau and the ATCA observed the other two systems.

    CSIRO ATCA at the Paul Wild Observatory, about 25 km west of the town of Narrabri in rural NSW about 500 km north-west of Sydney, AU

    “This is the first clear detection of anomalous microwave emission coming from protoplanetary disks,” said David Frayer a coauthor on the paper and astronomer with the Green Bank Observatory.

    The astronomers also note that the infrared light coming from these systems matches the unique signature of nanodiamonds. Other protoplanetary disks throughout the Milky Way, however, have the clear infrared signature of PAHs yet show no signs of the AME light.

    This strongly suggests that PAHs are not the mysterious source of anomalous microwave radiation, as astronomers once thought. Rather, hydrogenated nanodiamonds, which form naturally within protoplanetary disks and are found in meteorites on Earth, are the most likely source of AME light in our galaxy.

    “In a Sherlock Holmes-like method of eliminating all other causes, we can confidently say the best candidate capable of producing this microwave glow is the presence of nanodiamonds around these newly formed stars,” said Greaves. Based on their observations, the astronomers estimate that up to 1-2 percent of the total carbon in these protoplanetary disks has gone into forming nanodiamonds.

    Evidence for nanodiamonds in protoplanetary disks has grown over the past several decades. This is, however, the first clear connection between nanodiamonds and AME in any setting.

    Statistical models also strongly support the premise that nanodiamonds are abundant around infant stars and are responsible for the anomalous microwave emission found there. “There is a one in 10,000 chance, or less, that this connection is due to chance,” said Frayer.

    For their research, the astronomers used the GBT and ATCA to survey 14 young stars across the Milky Way for hints of anomalous microwave emission. AME was clearly seen in 3 of the 14 stars, which are also the only 3 stars of the 14 that show the IR spectral signature of hydrogenated nanodiamonds. “In fact, these are so rare,” notes Greaves, “no other young stars have the confirmed infrared imprint.”

    This detection has interesting implications for the study of cosmology and the search for evidence that our universe began with a period of inflation. If immediately after the Big Bang, our universe grew at a pace that vastly outstripped the speed of light, a trace of that period of inflation should be seen in a peculiar polarization of the cosmic microwave background. Though this signature of polarization has yet to be conclusively detected, the work by Greaves and her colleagues offers some hope that it could be.

    “This is good news for those who study polarization of the cosmic microwave background, since the signal from spinning nanodiamonds would be weakly polarized at best,” said Brian Mason, an astronomer at the National Radio Astronomy Observatory and coauthor on the paper. “This means that astronomers can now make better models of the foreground microwave light from our galaxy, which must be removed to study the distant afterglow of the Big Bang.”

    Nanodiamonds likely form out of a superheated vapor of carbon atoms in highly energized star-forming regions. This is not unlike industrial methods of creating nanodiamonds on Earth.

    In astronomy, nanodiamonds are special in that their structure produces what is known as a “dipole moment” – an arrangement of atoms that allows them to emit electromagnetic radiation when they spin. Because these particles are so small – smaller than normal dust particles in a protoplanetary disk — they are able to spin exceptionally fast, emitting radiation in the microwave range rather than in the meter-wavelength range, where galactic and intergalactic radiation would probably drown it out.

    “This is a cool and unexpected resolution to the puzzle of anomalous microwave radiation,” concluded Greaves. “It’s even more interesting that it was obtained by looking at protoplanetary disks, shedding light on the chemical features of early solar systems, including our own.”

    “It is an exciting result,” concluded co-author Anna Scaife from Manchester University. “It’s not often you find yourself putting new words to famous tunes, but ‘AME in the Sky with Diamonds’ seems a thoughtful way of summarizing our research.”

    Future centimeter-wave instruments, like the planned Band 1 receivers on ALMA and the Next Generation Very Large Array, will be able to study this phenomenon in much greater detail. Now that there is a physical model and, for the first time, a clear spectral signature, astronomers expect our understanding will improve quickly.

    See the full article here .


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    Mission Statement

    Green Bank Observatory enables leading edge research at radio wavelengths by offering telescope, facility and advanced instrumentation access to the astronomy community as well as to other basic and applied research communities. With radio astronomy as its foundation, the Green Bank Observatory is a world leader in advancing research, innovation, and education.

    History

    60 years ago, the trailblazers of American radio astronomy declared this facility their home, establishing the first ever National Radio Astronomy Observatory within the United States and the first ever national laboratory dedicated to open access science. Today their legacy is alive and well.

     
  • richardmitnick 3:59 pm on April 30, 2018 Permalink | Reply
    Tags: , , , , GBO -Green Bank Observatory, , , Phased Array Feeds,   

    From National Radio Astronomy Observatory via newswise: “New Technology Offers to Broaden Vision for Radio Astronomy” 

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    National Radio Astronomy Observatory

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    @newswise

    newswise

    30-Apr-2018

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    Infographic demonstrating the layout of the newly designed Phased Array Feed receiver that was tested on the Green Bank Telescope. Credit: NRAO/AUI/NSF; S. Dangello.



    GBO radio telescope, Green Bank, West Virginia, USA

    To accelerate the pace of discovery and exploration of the cosmos, a multi-institution team of astronomers and engineers has developed a new and improved version of an unconventional radio-astronomy imaging system known as a Phased Array Feed (PAF). This remarkable instrument can survey vast swaths of the sky and generate multiple views of astronomical objects with unparalleled efficiency.

    Looking nothing like a camera or other traditional imaging technologies – like CCDs in optical telescopes or single receivers in radio telescopes – this new Phased Array Feed design resembles a forest of miniature tree-like antennas evenly arranged on a meter-wide metal plate. When mounted on a single-dish radio telescope, specialized computers and signal processors are able to combine the signals among the antennas to create a virtual multi-pixel camera.

    This type of instrument is particularly useful in a number of important areas of astronomical research, including the study of hydrogen gas raining in on our galaxy and in searches for enigmatic Fast Radio Bursts.

    Over the years, various other radio astronomy research facilities have developed phased array receiver designs. Most, however, have not achieved the efficiency necessary to compete with classical radio receiver designs, which process one signal from one spot on the sky at a time. The value of the new PAF is that it can form multiple views (or “beams on the sky,” in radio astronomy terms) with the same efficiency as a classical receiver, which can enable faster scans of multiple astronomical targets.

    This newly developed system helps take Phased Array Feed technology from a curious area of research to a highly efficient, multipurpose tool for exploring the universe.

    Commissioning observations with the National Science Foundation’s Green Bank Telescope (GBT) using this new design show that this instrument met and exceeded all testing goals. It also achieved the lowest operating noise temperature – a normally vexing problem for clear views of the sky — of any phased array receiver to date. This milestone is critical to move the technology from an experimental design to a fully fledged observing instrument.

    The results are published in The Astronomical Journal.

    “When looking at all phased array receiver technologies currently operating or in development, our new design clearly raises the bar and gives the astronomy community a new, more rapid way of conducting large-scale surveys,” said Anish Roshi, an astronomer-engineer with the National Radio Astronomy Observatory (NRAO) and a member of the design team.

    The new PAF was designed by a consortium of institutions: the NRAO’s Central Development Laboratory, Green Bank Observatory, and Brigham Young University.

    “The collaborative work that went into designing, building, and ultimately verifying this remarkable system is truly astounding,” said NRAO Director Tony Beasley. “It highlights the fact that new and emerging radio astronomy technology can have an immense impact on research.”

    The new PAF design consists of 19 dipole antennas, radio receivers that resemble miniature umbrellas without a covering. A dipole, which simply means “two poles,” is the most basic type of antenna. Its length determines the frequency — or wavelength of radio light — it is able to receive. In the PAF radio system, the strength of the signal can vary across the surface of the array. By calculating how the signal is received by each of the antennas, the system produces what is known as a “point-spread function” – essentially, a pattern of dots concentrated in one region.

    The PAF’s computer and signal processors can calculate up to seven point-spread functions at a time, enabling the receiver to synthesize seven individual beams on the sky. The new design also allows these regions to overlap, creating a more comprehensive view of the region of space being surveyed.

    “This project brings together in one instrument a state-of-the-art, low-noise receiver design, next generation multi-channel digital radio technology, and advanced phased array modeling and beamforming,” said Bill Shillue, PAF group lead at the NRAO’s Central Development Laboratory.

    The astronomical value of the receiver was demonstrated by GBT observations of the pulsar B0329+54 and the Rosette Nebula, a star-forming region of the Milky Way filled with ionized hydrogen gas.

    Additional development and computing power could enable this same design to generated an even greater number of beams on the sky, greatly expanding its utility.

    The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

    See the full article here.

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    NRAO/Karl V Jansky VLA, on the Plains of San Agustin fifty miles west of Socorro, NM, USA

    The NRAO operates a complementary, state-of-the-art suite of radio telescope facilities for use by the scientific community, regardless of institutional or national affiliation: the Very Large Array (VLA), and the Very Long Baseline Array (VLBA)*.

    ESO/NRAO/NAOJ ALMA Array in Chile in the Atacama at Chajnantor plateau, at 5,000 metres

    Access to ALMA observing time by the North American astronomical community will be through the North American ALMA Science Center (NAASC).

    NRAO VLBA

    NRAO VLBA

    *The Very Long Baseline Array (VLBA) comprises ten radio telescopes spanning 5,351 miles. It’s the world’s largest, sharpest, dedicated telescope array. With an eye this sharp, you could be in Los Angeles and clearly read a street sign in New York City!

    Astronomers use the continent-sized VLBA to zoom in on objects that shine brightly in radio waves, long-wavelength light that’s well below infrared on the spectrum. They observe blazars, quasars, black holes, and stars in every stage of the stellar life cycle. They plot pulsars, exoplanets, and masers, and track asteroids and planets.

    And the future Expanded Very Large Array (EVLA).

     
  • richardmitnick 1:34 pm on March 22, 2018 Permalink | Reply
    Tags: "Leading Arm" in the Magellanic Cloud swarf galaxies, , , , , GBO -Green Bank Observatory,   

    From Hubble: “Hubble Solves Cosmic ‘Whodunit’ with Interstellar Forensics” 

    NASA Hubble Banner

    NASA/ESA Hubble Telescope

    NASA/ESA Hubble Telescope

    Mar 22, 2018

    Ann Jenkins
    Space Telescope Science Institute, Baltimore, Maryland
    410-338-4488
    jenkins@stsci.edu

    Ray Villard
    Space Telescope Science Institute, Baltimore, Maryland
    410-338-4514
    villard@stsci.edu

    Andrew Fox
    Space Telescope Science Institute, Baltimore, Maryland
    410-338-5083
    afox@stsci.edu

    Image credits: D. Nidever et al., NRAO/AUI/NSF and A. Mellinger, Leiden-Argentine-Bonn (LAB) Survey, Parkes Observatory, Westerbork Observatory, Arecibo Observatory, and A. Feild (STScI)

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    Winner Declared in Tug-of-War Between Two Satellite Galaxies of the Milky Way
    In a cosmic tug-of-war between two dwarf galaxies orbiting the Milky Way, only NASA’s Hubble Space Telescope can see who’s winning. The players are the Large and Small Magellanic Clouds, and as they gravitationally tug at each other, one of them has pulled out a huge amount of gas from its companion.

    Large Magellanic Cloud. Adrian Pingstone December 2003

    Small Magellanic Cloud. NASA/ESA Hubble and ESO/Digitized Sky Survey 2

    This shredded and fragmented gas, called the Leading Arm, is being devoured by the Milky Way and feeding new star birth in our galaxy. But which dwarf galaxy is doing the pulling, and whose gas is now being feasted upon? Scientists used Hubble’s ultraviolet vision to chemically analyze the gas in the Leading Arm and determine its origin. After years of debate, we now have the answer to this “whodunit” mystery.

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    On the outskirts of our galaxy, a cosmic tug-of-war is unfolding—and only NASA’s Hubble Space Telescope can see who’s winning.

    The players are two dwarf galaxies, the Large Magellanic Cloud and the Small Magellanic Cloud, both of which orbit our own Milky Way Galaxy. But as they go around the Milky Way, they are also orbiting each other. Each one tugs at the other, and one of them has pulled out a huge cloud of gas from its companion.

    Called the Leading Arm, this arching collection of gas connects the Magellanic Clouds to the Milky Way. Roughly half the size of our galaxy, this structure is thought to be about 1 or 2 billion years old. Its name comes from the fact that it’s leading the motion of the Magellanic Clouds.

    The enormous concentration of gas is being devoured by the Milky Way and feeding new star birth in our galaxy. But which dwarf galaxy is doing the pulling, and whose gas is now being feasted upon? After years of debate, scientists now have the answer to this “whodunit” mystery.

    “There’s been a question: Did the gas come from the Large Magellanic Cloud or the Small Magellanic Cloud? At first glance, it looks like it tracks back to the Large Magellanic Cloud,” explained lead researcher Andrew Fox of the Space Telescope Science Institute in Baltimore, Maryland. “But we’ve approached that question differently, by asking: What is the Leading Arm made of? Does it have the composition of the Large Magellanic Cloud or the composition of the Small Magellanic Cloud?”

    Fox’s research is a follow-up to his 2013 work, which focused on a trailing feature behind the Large and Small Magellanic Clouds. This gas in this ribbon-like structure, called the Magellanic Stream, was found to come from both dwarf galaxies. Now Fox wondered about its counterpart, the Leading Arm. Unlike the trailing Magellanic Stream, this tattered and shredded “arm” has already reached the Milky Way and survived its journey to the galactic disk.

    The Leading Arm is a real-time example of gas accretion, the process of gas falling onto galaxies. This is very difficult to see in galaxies outside the Milky Way, because they are too far away and too faint. “As these two galaxies are in our backyard, we essentially have a front-row seat to view the action,” said collaborator Kat Barger at Texas Christian University.

    In a new kind of forensics, Fox and his team used Hubble’s ultraviolet vision to chemically analyze the gas in the Leading Arm. They observed the light from seven quasars, the bright cores of active galaxies that reside billions of light-years beyond this gas cloud. Using Hubble’s Cosmic Origins Spectrograph, the scientists measured how this light filters through the cloud.

    In particular, they looked for the absorption of ultraviolet light by oxygen and sulfur in the cloud. These are good gauges of how many heavier elements reside in the gas. The team then compared Hubble’s measurements to hydrogen measurements made by the National Science Foundation’s Robert C. Byrd Green Bank Telescope at the Green Bank Observatory in West Virginia, as well as several other radio telescopes.



    GBO radio telescope, Green Bank, West Virginia, USA

    “With the combination of Hubble and Green Bank Telescope observations, we can measure the composition and velocity of the gas to determine which dwarf galaxy is the culprit,” explained Barger.

    After much analysis, the team finally had conclusive chemical “fingerprints” to match the origin of the Leading Arm’s gas. “We’ve found that the gas matches the Small Magellanic Cloud,” said Fox. “That indicates the Large Magellanic Cloud is winning the tug-of-war, because it has pulled so much gas out of its smaller neighbor.”

    This answer was possible only because of Hubble’s unique ultraviolet capability. Because of the filtering effects of Earth’s atmosphere, ultraviolet light cannot be studied from the ground. “Hubble is the only game in town,” explained Fox. “All the lines of interest, including oxygen and sulfur, are in the ultraviolet. So if you work in the optical and infrared, you can’t see them.”

    Gas from the Leading Arm is now crossing the disk of our galaxy. As it crosses, it interacts with the Milky Way’s own gas, becoming shredded and fragmented.

    This is an important case study of how gas gets into galaxies and fuels star birth. Astronomers use simulations and try to understand the inflow of gas in other galaxies. But here, the gas is being caught red-handed as it moves across the Milky Way’s disk. Sometime in the future, planets and solar systems in our galaxy may be born out of material that used to be part of the Small Magellanic Cloud.

    The team’s study appears in the Feb. 20 issue of The Astrophysical Journal.
    As Fox and his team look ahead, they hope to map out the full size of the Leading Arm—something that is still unknown.

    Also see:
    Chemical Composition of Young Stars in the Leading Arm of the Magellanic System
    The Astrophysical Journal

    The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, in Washington, D.C.

    See the full article here .

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    The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI), is a free-standing science center, located on the campus of The Johns Hopkins University and operated by the Association of Universities for Research in Astronomy (AURA) for NASA, conducts Hubble science operations.

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  • richardmitnick 9:41 am on March 15, 2018 Permalink | Reply
    Tags: "little green men” Documentary Presentation, , , , , GBO -Green Bank Observatory,   

    From GBO: ““little green men” Documentary Presentation” 

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    Green Bank Radio Telescope, West Virginia, USA
    Green Bank Radio Telescope, West Virginia, USA

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    Green Bank Observatory

    1
    Learn about the Pulsar Collaboratory Program that is enabling West Virginia high school students to use the Green Bank Telescopes in Pocahontas County to search for exotic stars called pulsars.

    “little green men” Documentary Presentation

    Enjoy a film documentary on the program followed by a discussion with film producers as well as astronomers and students involved in the program.

    Details

    Date:
    March 20
    Time:
    6:00 pm – 8:00 pm
    Event Category:
    Caperton Planetarium and Theater

    2
    All activities will take place in the Caperton Planetarium and Theater and are free to the public.
    304-561-3570 1 Clay Square | Charleston, WV 25301

    See the full article here .

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    Mission Statement

    Green Bank Observatory enables leading edge research at radio wavelengths by offering telescope, facility and advanced instrumentation access to the astronomy community as well as to other basic and applied research communities. With radio astronomy as its foundation, the Green Bank Observatory is a world leader in advancing research, innovation, and education.

    History

    60 years ago, the trailblazers of American radio astronomy declared this facility their home, establishing the first ever National Radio Astronomy Observatory within the United States and the first ever national laboratory dedicated to open access science. Today their legacy is alive and well.

     
  • richardmitnick 9:43 pm on March 1, 2018 Permalink | Reply
    Tags: , , , , , GBO -Green Bank Observatory, NANOGrav-North American Nanohertz Observatory for Gravitational Waves, , ,   

    From GBO: “Pulsar Watchers Close In On Galaxy Merger History” 

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    Green Bank Radio Telescope, West Virginia, USA
    Green Bank Radio Telescope, West Virginia, USA

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    Green Bank Observatory

    2018-02-28
    Paul Vosteen

    1
    Astronomers see galaxies merging throughout the universe, some of which should result in binary supermassive black holes. Credit: NASA

    Fifty years after pulsar discovery published, massive new data set moves closer to finding very-low-frequency gravitational waves, researchers say.

    For the past twelve years, a group of astronomers have been watching the sky carefully, timing pulses of radio waves being emitted by rapidly spinning stars called pulsars, first discovered 50 years ago. These astronomers are interested in understanding pulsars, but their true goal is much more profound; the detection of a new kind of gravitational waves. With a new, more sophisticated analysis, they are much closer than ever before.

    Gravitational waves are wrinkles in space-time that stretch and squeeze the distances between objects. In 2015, a hundred years after Albert Einstein realized that accelerating massive objects should produce them, these waves were finally detected from black holes with masses roughly 30 times the mass of our sun colliding with each other. However, Einstein’s theory also predicts another kind of wave, one that comes from the mergers of black holes with masses of hundred million times the sun’s.

    Astronomers believe that nearly all galaxies have supermassive black holes at their centers. When two galaxies collide, these black holes will slowly fall toward each other, finally merging long after the initial galaxy collision. In the last stage of this process, as the two black holes spiral closer to each other, strong gravitational waves can be produced.

    While these waves travel at the speed of light, their strength varies quite slowly, on timescales ranging from months to years. This means that gravitational wave observatories on Earth can’t measure them. For that, you need an observatory with detectors light-years apart.

    “We know that galaxy mergers are an important part of galaxy growth and evolution through cosmic time. By detecting gravitational waves from supermassive binary black holes at the cores of merging galaxies, we will be able to probe how galaxies are shaped by those black holes,” said Sarah Burke-Spolaor, assistant professor at West Virginia University.

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    Nature publication of the discovery of pulsar B1919+21. Credit: Reproduced by permission from Springer Nature

    Fifty years ago, the February 24, 1968 edition of the journal Nature provided the solution, with the discovery of a new kind of star. This new star was curious, emitting regular radio pulses once every 1.3 seconds. Graduate student Jocelyn Bell (now Dr. Bell Burnell [now really Dame Susan Jocelyn Bell Burnell, one of the many women denied a deserved Nobel]) was the first to spot the signal, seeing it as “a bit of scruff” in her radio surveys. Zooming in on the scruff, Bell saw the regular pulses from the star.

    After first entertaining the possibility that the pulses could be the result of LGM, or “little green men,” the new star was dubbed a pulsar, with the understanding that the pulses represented the rotation rate of the star. Such a rapid rotation rate meant that the star must be small, about the size of a city. Only a few years later, a pulsar in a binary system was found, and the first mass estimate indicated that this tiny object held about one and a half times the mass of our sun.

    “Before this time, no one thought stars so small could actually exist! It wasn’t until a pulsar was found at the center of a supernova remnant in 1968 that astronomers realized that pulsars were neutron stars born in the explosions of massive stars,” said Maura McLaughlin, professor at West Virginia University.

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    After detecting unexpected signals at the same location in the sky (top left), graduate student Jocelyn Bell (right) [now Dame Susan Jocelyn Bell Burnell] observed individual pulses from the new source (bottom left) in late 1967. Credit: UK National Science & Media Museum

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    2009 Dame Susan Jocelyn Bell Burnell. Wikipedia

    The fastest pulsars, called millisecond pulsars, spin hundreds of times every second (faster than your kitchen blender!), and are the most stable natural clocks known in the universe. Pulsar astronomers around the globe are monitoring these stellar clocks in order to form a new kind of cosmic gravitational wave detector known as a “Pulsar Timing Array.” By carefully measuring when radio pulses arrive from millisecond pulsars, astronomers can track the tiny changes in the distance from the Earth to the pulsars caused by the stretching and squeezing of spacetime due to a gravitational wave.

    In the US and Canada, a group called NANOGrav (North American Nanohertz Observatory for Gravitational Waves) is searching for these gravitational waves using some of the largest telescopes in the world, including the Green Bank Telescope in West Virginia and the Arecibo Observatory in Puerto Rico.

    NAIC/Arecibo Observatory, Puerto Rico, USA, at 497 m (1,631 ft)

    NANOGrav routinely joins forces with groups in Europe and Australia to improve their sky coverage and sensitivity. Collectively known as the International Pulsar Timing Array, the combined observations from these groups constitute the most sensitive data set in the world for searching for low-frequency gravitational waves.

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    International Pulsar Timing Array

    This month, fifty years after the publication of the first pulsar discovery, NANOGrav has submitted a pair of companion papers to The Astrophysical Journal describing eleven years of monthly observations of 45 millisecond pulsars along with the astrophysical implications of their results. For the first time, the data set includes a six-pulsar “high-frequency” sample, with measurements made every week to expand the pulsar timing array’s sensitivity range. NANOGrav is able to set sensitive upper limits that constrain the physical processes at play in galaxy mergers. As their sensitivity improves, NANOGrav is uncovering new sources of background noise that must be accounted for. Most recently, uncertainties in the pull of Jupiter on the sun have been found to affect pulsar timing. As a result, the team is implementing new computational methods to account for this, in effect determining Jupiter’s orbit more precisely than possible except by planetary missions.

    “This is the most sensitive pulsar timing dataset ever created for both gravitational wave analysis and a host of other astrophysical measurements. And with each new release, we will add more pulsars and data, which increase our sensitivity to gravitational waves”, said David Nice, professor at Lafayette College.

    Last year, the journal that announced the discovery of pulsars once again played host to a pulsar first. In November, Nature Astronomy published their first-ever article describing the gravitational wave environment that pulsar timing arrays are working to uncover. By looking at galaxy surveys, the article estimates there are about 100 supermassive black hole binaries that are close enough to affect pulsar timing array measurements. Given their expected future sensitivity, the authors state that pulsar timing arrays should be able to isolate the gravitational waves from a specific individual galaxy within about 10 years.

    “From city-sized pulsars spinning fast in galaxies to large, massive galaxies themselves and their merging central black holes, all in 50 years! That is a large step for humankind, and not one that we could have foreseen. What will the next 50 years bring? Pulsars and gravitational waves will continue to be big news, I’m sure!” said Jocelyn Bell Burnell.

    A century after Einstein first predicted them, gravitational waves were finally detected. Now, 50 years after Jocelyn Bell’s discovery, pulsars have become a new tool for measuring both gravitational waves and the distant black holes that create them. If predictions are correct, the next decade will be an exciting period of discovery for radio astronomers, pulsars, and gravitational waves!

    Links to supporting materials:
    1-page summary of 11-year results: https://nanograv.github.io/11yr_stochastic_analysis/ Submitted to the Astrophysical Journal, Dec 31, 2017

    11-Year Data Release paper: https://arxiv.org/abs/1801.01837 Submitted to The Astrophysical Journal

    Gravitational Wave Search paper: https://arxiv.org/abs/1801.02617 Submitted to The Astrophysical Journal

    See the full article here .

    Please help promote STEM in your local schools.

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    gbo-science-building

    Mission Statement

    Green Bank Observatory enables leading edge research at radio wavelengths by offering telescope, facility and advanced instrumentation access to the astronomy community as well as to other basic and applied research communities. With radio astronomy as its foundation, the Green Bank Observatory is a world leader in advancing research, innovation, and education.

    History

    60 years ago, the trailblazers of American radio astronomy declared this facility their home, establishing the first ever National Radio Astronomy Observatory within the United States and the first ever national laboratory dedicated to open access science. Today their legacy is alive and well.

     
  • richardmitnick 7:48 am on February 7, 2018 Permalink | Reply
    Tags: Astronomers peer into the lair of a mysterious source of cosmic radio bursts, , , , , , GBO -Green Bank Observatory, ,   

    From GBO: “Astronomers peer into the lair of a mysterious source of cosmic radio bursts” 

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    Green Bank Radio Telescope, West Virginia, USA
    Green Bank Radio Telescope, West Virginia, USA

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    Green Bank Observatory

    2018-01-10
    Paul Vosteen
    Media Specialist; Education & Public Outreach
    Green Bank Observatory
    +1.304.456.2212
    pvosteen@nrao.edu

    Contact:
    Dr. Jason Hessels, University of Amsterdam, Anton Pannekoek Institute for Astronomy / ASTRON – Netherlands Institute for Radio Astronomy
    E-mail: J.W.T.Hessels@uva.nl
    Tel: +31 (0)610260062

    Daniele Michilli, University of Amsterdam, Anton Pannekoek Institute for Astronomy / ASTRON – Netherlands Institute for Radio Astronomy
    E-mail: danielemichilli@gmail.com

    Dr. Andrew Seymour, National Astronomy and Ionosphere Center Arecibo Observatory, Puerto Rico
    E-mail: seymour.andrew@gmail.com

    Dr. Laura Spitler, Max-Planck-Institute for Radioastronomy, Bonn, Germany
    E-mail: lspitler@mpifr-bonn.mpg.de

    Dr. Shami Chatterjee, Cornell University
    Tel: +1 (607) 279 2076
    E-mail: shami@astro.cornell.edu

    Dr. Ryan Lynch, Green Bank Observatory
    Tel: 1+ (304) 456 2357
    E-mail: rlynch@nrao.edu

    1
    Artist concept of fast radio burst. Image Credit: Design: Danielle Futselaar; photo usage: shutterstock.com

    Using two of the world’s largest radio telescopes, an international team of astronomers have gained new insight into the extreme home of a mysterious source of cosmic radio bursts. The discovery suggests that the source of the radio emission lies near a massive black hole or within an extremely powerful nebula, and may help shed light on what is causing these strange bursts.

    The team presented their findings at the American Astronomical Society’s winter meeting (#AAS231) in Washington, D.C. The results are presented in the journal Nature.

    Using data from the Arecibo Observatory in Puerto Rico and the Green Bank Telescope in West Virginia, researchers have shown that the radio bursts from an object known as FRB121102 have a property known as polarization, and are “twisted” through a process called Faraday rotation.

    NAIC/Arecibo Observatory, Puerto Rico, USA, at 497 m (1,631 ft)

    “I couldn’t believe my eyes when I first saw the data. Such extreme Faraday rotation is unprecedented,” says Jason Hessels of the University of Amsterdam and ASTRON (Netherlands Institute for Radio Astronomy), the leader of the team.

    FRB121102 is an example of a fast radio burst (FRB) – a mysterious and very short flash of radio waves emanating from deep in extragalactic space. The home galaxy of FRB121102 is located 3 billion light-years from Earth; at this distance, the bursts must be nearly 100 million times more powerful than the Sun to be seen from Earth. The cause of FRBs is one of the biggest mysteries in astronomy today. “FRB 121102 was already unique because it repeats, which hasn’t yet been observed in any other FRBs; now the huge Faraday rotation we have detected singles it out yet again. We’re curious as to whether these two unique aspects are linked,” says Daniele Michilli, a PhD candidate at the University of Amsterdam and ASTRON (Netherlands Institute for Radio Astronomy).

    Faraday rotation occurs when polarized light travels through a strongly magnetized, hot gas known as plasma. Faraday rotation this strong has not been found anywhere else in the Universe, though the conditions near the black hole that lies at the center of Earth’s own Milky Way galaxy come close. This leads researchers to propose that FRB121102 could be located near a massive black hole of its own, or embedded within the remains of a dead star.

    Key to the discovery was detecting the bursts at a higher radio frequency than ever before. “At the Arecibo Observatory, we developed a new observing setup and additional hardware that allowed us to observe at these higher frequencies,” says Andrew Seymour, staff astronomer at the National Astronomy and Ionosphere Center, which operates Arecibo. “What’s more, one of the bursts we detected lasted less than 30 microseconds. Such a short duration argues that the bursts originate from a neutron star in an extreme environment of magnetized plasma,” he adds.

    “Our partners in the Breakthrough Listen project were able to use the Green Bank Telescope and a fantastic new instrument that they built to observe this source over the widest range of radio frequencies to-date, confirming what had been seen at Arecibo Observatory. It’s such a surprising result, so this was a really important step in convincing everyone that this unprecedented degree of Faraday rotation is real,” explains Ryan Lynch, a staff scientist at the Green Bank Observatory.

    As a fun way of visualizing the shapes of the bursts, team member Anne Archibald (University of Amsterdam) has made 3D printed models, which show the brightness of each burst as a function of both time and the observed radio frequency. These designs are freely available for download at https://www.thingiverse.com/thing:2723399.

    In future research, the astronomers hope to distinguish between the two leading hypotheses – either a neutron star near a black hole or one embedded in a powerful nebula – or possibly other, more exotic interpretations, by monitoring how the Faraday rotation and other properties of the bursts change with time. With a number of wide-field radio telescopes now coming online, more such sources are expected to be discovered in the coming year, and astronomers are poised to answer more fundamental questions about FRBs.

    See the full article here .

    Please help promote STEM in your local schools.

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    Stem Education Coalition

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    Mission Statement

    Green Bank Observatory enables leading edge research at radio wavelengths by offering telescope, facility and advanced instrumentation access to the astronomy community as well as to other basic and applied research communities. With radio astronomy as its foundation, the Green Bank Observatory is a world leader in advancing research, innovation, and education.

    History

    60 years ago, the trailblazers of American radio astronomy declared this facility their home, establishing the first ever National Radio Astronomy Observatory within the United States and the first ever national laboratory dedicated to open access science. Today their legacy is alive and well.

     
  • richardmitnick 8:52 pm on January 10, 2018 Permalink | Reply
    Tags: , , , , GBO -Green Bank Observatory, Swarm of Hydrogen Clouds Flying Away from Center of our Galaxy   

    From GBO: “Swarm of Hydrogen Clouds Flying Away from Center of our Galaxy” 

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    Green Bank Radio Telescope, West Virginia, USA
    Green Bank Radio Telescope, West Virginia, USA

    gbo-sign

    Green Bank Observatory

    Contact:
    Mike Holstine
    Business Manager, Green Bank Observatory
    +1 (304) 456-2011
    michaelholstine@gbobservatory.org

    2018-01-10
    Paul Vosteen

    1
    Photo Source: S. Brunier; Design & Illustration: P. Vosteen

    A team of astronomers has discovered what appears to be a grand exodus of more than 100 hydrogen clouds streaming away from the center of the Milky Way and heading into intergalactic space. This observation, made with the National Science Foundation’s Green Bank Telescope (GBT), may give astronomers a clearer picture of the so-called Fermi Bubbles, giant balloons of superheated gas billowing out above and below the disk of our galaxy.

    The results are presented today at the 231st meeting of the American Astronomical Society in Washington, D.C.

    “The center of the Milky Way is a special place,” notes Jay Lockman, an astronomer at the Green Bank Observatory in West Virginia. “At its heart is a black hole several million times more massive than the Sun and there are regions of intense star birth and explosive star destruction.”

    These energetic processes, perhaps individually or together, have generated a powerful cosmic “wind” that has blown two enormous bubbles above and below the disk of the Milky Way that are filled with gas at tens-of-millions of degrees. This superheated gas, however, shines feebly at radio, X-ray and gamma-ray wavelengths.

    The bubbles appear prominently in observations made by NASA’s Fermi Gamma-ray Space Telescope, which is why astronomers refer to them as the Fermi Bubbles.

    NASA/Fermi Gamma Ray Space Telescope

    “One problem that hinders study of this hot cosmic wind is that the gas has such low density that its emission is very faint, so there is no practical way to track its motion,” notes Lockman. “This is where the hydrogen clouds come in.”

    Just like a handful of dust thrown into the air can show the motion of wind on Earth, the hydrogen clouds can act as test particles revealing the flow of the hotter, invisible wind from the center of the Milky Way.

    Neutral hydrogen gas, the principal component of these clouds, shines brightly at the radio wavelength of 21 centimeters. These hydrogen clouds were first discovered by a team led by Naomi McClure-Griffiths of the Australian National University using a radio telescope array in Australia. However, that survey was confined to a region just a few degrees around the galactic center, so it gave only limited information on the number and extent of these clouds.

    New research with the 100-meter GBT greatly extends these observations.

    A group led by Lockman, McClure-Griffiths, and Enrico DiTeodoro, who is also with the Australian National University, mapped a much larger area around the galactic center in search of additional hydrogen clouds that might be entrained in the nuclear wind. They found a gigantic swarm of more than 100 high-velocity gas clouds. The properties of these clouds allow the scientists to learn about the shape of the wind-blown region and the enormous energies that are involved.

    “The signature of these clouds being blown out of the Milky Way is that their velocities are crazy,” said Lockman. “Gas motions in the Milky Way are usually quite regular and are dominated by the orderly rotation of the Galaxy. In the Fermi Bubbles we see clouds right next to each other on the sky that have velocities differing by as much as 400 kilometers per second.”

    According to the researchers, the most likely explanation for these wildly differing velocities is that they’re traveling within a cone of material that is expanding upward and away from the galactic center, so the front portion is coming toward us and the back part is flying away.

    By modeling the distribution and velocities of the clouds, the astronomers found that they would fill a cone stretching above and below the galaxy to a distance of at least 5,000 light-years from the center. The clouds have an average speed of about 330 kilometers per second.

    Di Teodoro notes: “What is especially puzzling is that we have not yet found the edge of the swarm of clouds. Somewhere above the galactic center, the hydrogen clouds have to dissipate or become ionized. But we have not found that edge yet, so there’s still a lot to learn.”

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    gbo-science-building

    Mission Statement

    Green Bank Observatory enables leading edge research at radio wavelengths by offering telescope, facility and advanced instrumentation access to the astronomy community as well as to other basic and applied research communities. With radio astronomy as its foundation, the Green Bank Observatory is a world leader in advancing research, innovation, and education.

    History

    60 years ago, the trailblazers of American radio astronomy declared this facility their home, establishing the first ever National Radio Astronomy Observatory within the United States and the first ever national laboratory dedicated to open access science. Today their legacy is alive and well.

     
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