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New Use for a Century-Old Relativity Experiment to Measure a White Dwarf's Mass

New Use for a Century-Old Relativity Experiment to Measure a White Dwarf's Mass | Amazing Science | Scoop.it

Astronomers have used the sharp vision of NASA’s Hubble Space Telescope to repeat a century-old test of Einstein’s general theory of relativity. The team measured the mass of white dwarf Stein 2051 B, the burned-out remnant of a normal star, by seeing how much it deflects the light from a background star. The gravitational microlensing method data provide a solid estimate of the white dwarf’s mass and yield insights into theories of the structure and composition of the burned-out star.

 

Albert Einstein reshaped our understanding of the fabric of space. In his general theory of relativity in 1915, he proposed the revolutionary idea that massive objects warp space, due to the effects of gravity. Until that time, Isaac Newton's theory of gravity from two centuries earlier held sway: that space was unchanging. Einstein's theory was experimentally verified four years later when a team led by British astronomer Sir Arthur Eddington measured how much the sun's gravity deflected the image of a background star as its light grazed the sun during a solar eclipse.

 

Astronomers had to wait a century, however, to build telescopes powerful enough to detect this gravitational warping phenomenon caused by a star outside our solar system. The amount of deflection is so small only the sharpness of the Hubble Space Telescope could measure it. Hubble observed the nearby white dwarf star Stein 2051 B as it passed in front of a background star. During the close alignment, the white dwarf's gravity bent the light from the distant star, making it appear offset by about 2 milliarcseconds from its actual position. This deviation is so small that it is equivalent to observing an ant crawl across the surface of a quarter from 1,500 miles away.

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VLA Reveals Secondary Black Hole Near Supermassive Black Hole in Cygnus A Galaxy

VLA Reveals Secondary Black Hole Near Supermassive Black Hole in Cygnus A Galaxy | Amazing Science | Scoop.it
Astronomers were surprised when the VLA revealed that a bright new object has appeared near the core of a famous galaxy. They think it's a second supermassive black hole, indicating that the galaxy has merged with another in the past.

 

Pointing the National Science Foundation’s Very Large Array (VLA) at a famous galaxy for the first time in two decades, a team of astronomers got a big surprise, finding that a bright new object had appeared near the galaxy’s core. The object, the scientists concluded, is either a very rare type of supernova explosion or, more likely, an outburst from a second supermassive black hole closely orbiting the galaxy’s primary, central supermassive black hole.

 

The astronomers observed Cygnus A, a well-known and often-studied galaxy discovered by radio-astronomy pioneer Grote Reber in 1939. The radio discovery was matched to a visible-light image in 1951, and the galaxy, some 800 million light-years from Earth, was an early target of the VLA after its completion in the early 1980s. Detailed images from the VLA published in 1984 produced major advances in scientists’ understanding of the superfast “jets” of subatomic particles propelled into intergalactic space by the gravitational energy of supermassive black holes at the cores of galaxies. “This new object may have much to tell us about the history of this galaxy,” said Daniel Perley, of the Astrophysics Research Institute of Liverpool John Moores University in the U.K., lead author of a paper in the Astrophysical Journalannouncing the discovery.

 

“The VLA images of Cygnus A from the 1980s marked the state of the observational capability at that time,” said Rick Perley, of the National Radio Astronomy Observatory (NRAO). “Because of that, we didn’t look at Cygnus A again until 1996, when new VLA electronics had provided a new range of radio frequencies for our observations.” The new object does not appear in the images made then. “However, the VLA’s upgrade that was completed in 2012 made it a much more powerful telescope, so we wanted to have a look at Cygnus A using the VLA’s new capabilities,” Perley said.

 

Daniel and Rick Perley, along with Vivek Dhawan, and Chris Carilli, both of NRAO, began the new observations in 2015, and continued them in 2016. “To our surprise, we found a prominent new feature near the galaxy’s nucleus that did not appear in any previous published images. This new feature is bright enough that we definitely would have seen it in the earlier images if nothing had changed,” said Rick Perley. “That means it must have turned on sometime between 1996 and now,” he added.

 

The scientists then observed Cygnus A with the Very Long Baseline Array (VLBA) in November of 2016, clearly detecting the new object. A faint infrared object also is seen at the same location in Hubble Space Telescope and Keck observations, originally made between 1994 and 2002. The infrared astronomers, from Lawrence Livermore National Laboratory, had attributed the object to a dense group of stars, but the dramatic radio brightening is forcing a new analysis.

 

What is the new object? Based on its characteristics, the astronomers concluded it must be either a supernova explosion or an outburst from a second supermassive black hole near the galaxy’s center. While they want to watch the object’s future behavior to make sure, they pointed out that the object has remained too bright for too long to be consistent with any known type of supernova. “Because of this extraordinary brightness, we consider the supernova explanation unlikely,” Dhawan said.

While the new object definitely is separate from Cygnus A’s central supermassive black hole, by about 1500 light-years, it has many of the characteristics of a supermassive black hole that is rapidly feeding on surrounding material.

 

“We think we’ve found a second supermassive black hole in this galaxy, indicating that it has merged with another galaxy in the astronomically-recent past,” Carilli said. “These two would be one of the closest pairs of supermassive black holes ever discovered, likely themselves to merge in the future.”

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Astronomers Watch as Collapsing Star Turns Into a Black Hole

Astronomers Watch as Collapsing Star Turns Into a Black Hole | Amazing Science | Scoop.it
Using data from several telescopes, a team of astronomers watched as a massive, dying star was likely reborn as a black hole.

 

The doomed star, named N6946-BH1, was 25 times as massive as our sun. It began to brighten weakly in 2009. But, by 2015, it appeared to have winked out of existence. By a careful process of elimination, based on observations researchers eventually concluded that the star must have become a black hole. This may be the fate for extremely massive stars in the universe.

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How radioactive decay could support extraterrestrial life, study shows

How radioactive decay could support extraterrestrial life, study shows | Amazing Science | Scoop.it

In the icy bodies around our solar system, radiation emitted from rocky cores could break up water molecules and support hydrogen-eating microbes. To address this cosmic possibility, a University of Texas at San Antonio (UTSA) and Southwest Research Institute (SwRI) team modeled a natural water-cracking process called radiolysis. They then applied the model to several worlds with known or suspected interior oceans, including Saturn’s moon Enceladus, Jupiter’s moon Europa, Pluto and its moon Charon, as well as the dwarf planet Ceres.  

 “The physical and chemical processes that follow radiolysis release molecular hydrogen (H2), which is a molecule of astrobiological interest,” said Alexis Bouquet, lead author of the study published in the May edition of Astrophysical Journal Letters.

 

Radioactive isotopes of elements such as uranium, potassium, and thorium are found in a class of rocky meteorites known as chondrites. The cores of the worlds studied by Bouquet and his co-authors are thought to have chondrite-like compositions. Ocean water permeating the porous rock of the core could be exposed to ionizing radiation and undergo radiolysis, producing molecular hydrogen and reactive oxygen compounds.

 

Bouquet, a student in the joint doctoral program between UTSA’s Department of Physics and Astronomy and SwRI’s Space Science and Engineering Division, explained that microbial communities sustained by H2 have been found in extreme environments on Earth. These include a groundwater sample found nearly 2 miles deep in a South African gold mine and at hydrothermal vents on the ocean floor. That raises interesting possibilities for the potential existence of analogous microbes at the water-rock interfaces of ocean worlds such as Enceladus or Europa.

 

“We know that these radioactive elements exist within icy bodies, but this is the first systematic look across the solar system to estimate radiolysis. The results suggest that there are many potential targets for exploration out there, and that’s exciting,” says co-author Dr. Danielle Wyrick, a principal scientist in SwRI’s Space Science and Engineering Division.

One frequently suggested source of molecular hydrogen on ocean worlds is serpentinization. This chemical reaction between rock and water occurs, for example, in hydrothermal vents on the ocean floor.

 

The key finding of the study is that radiolysis represents a potentially important additional source of molecular hydrogen. While hydrothermal activity can produce considerable quantities of hydrogen, in porous rocks often found under seafloors, radiolysis could produce copious amounts as well.

 

Radiolysis may also contribute to the potential habitability of ocean worlds in another way. In addition to molecular hydrogen, it produces oxygen compounds that can react with certain minerals in the core to create sulfates, a food source for some kinds of microorganisms.

 

“Radiolysis in an ocean world’s outer core could be fundamental in supporting life. Because mixtures of water and rock are everywhere in the outer solar system, this insight increases the odds of abundant habitable real estate out there,” Bouquet said.

 

Co-authors of the article, “Alternative Energy: Production of H2 by Radiolysis of Water in the Rocky Cores of Icy Bodies,” are SwRI’s Dr. Christopher R. Glein, Wyrick, and Dr. J. Hunter Waite, who also serves as a UTSA adjoint professor. 

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Discovered: Fast-growing galaxies from early universe

Discovered: Fast-growing galaxies from early universe | Amazing Science | Scoop.it

A team of astronomers including Carnegie's Eduardo Bañados and led by Roberto Decarli of the Max Planck Institute for Astronomy has discovered a new kind of galaxy which, although extremely old--formed less than a billion years after the Big Bang--creates stars more than a hundred times faster than our own Milky Way.

Their findings are published by Nature.

 

The team's discovery could help solve a cosmic puzzle--a mysterious population of surprisingly massive galaxies from when the universe was only about 10 percent of its current age.

 

After first observing these galaxies a few years ago, astronomers proposed that they must have been created from hyper-productive precursor galaxies, which is the only way so many stars could have formed so quickly. But astronomers had never seen anything that fit the bill for these precursors until now.

 

This newly discovered population could solve the mystery of how these extremely large galaxies came to have hundreds of billions of stars in them when they formed only 1.5 billion years after the Big Bang, requiring very rapid star formation.

 

The team made this discovery by accident when investigating quasars, which are supermassive black holes that sit at the center of enormous galaxies, accreting matter. They were trying to study star formation in the galaxies that host these quasars. "But what we found, in four separate cases, were neighboring galaxies that were forming stars at a furious pace, producing a hundred solar masses' worth of new stars per year," Decarli explained.

 

"Very likely it is not a coincidence to find these productive galaxies close to bright quasars. Quasars are thought to form in regions of the universe where the large-scale density of matter is much higher than average. Those same conditions should also be conducive to galaxies forming new stars at a greatly increased rate," added Fabian Walter, also of Max Planck.


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A Whole New Jupiter: Newest Results from NASA’s Juno Mission

A Whole New Jupiter: Newest Results from NASA’s Juno Mission | Amazing Science | Scoop.it
Early science results from NASA’s Juno mission to Jupiter portray the largest planet in our solar system as a complex, gigantic, turbulent world, with Earth-sized polar cyclones, plunging storm systems that travel deep into the heart of the gas giant, and a mammoth, lumpy magnetic field that may indicate it was generated closer to the planet’s surface than previously thought.

“We are excited to share these early discoveries, which help us better understand what makes Jupiter so fascinating,” said Diane Brown, Juno program executive at NASA Headquarters in Washington. "It was a long trip to get to Jupiter, but these first results already demonstrate it was well worth the journey.”

Juno launched on Aug. 5, 2011, entering Jupiter’s orbit on July 4, 2016. The findings from the first data-collection pass, which flew within about 2,600 miles (4,200 kilometers) of Jupiter's swirling cloud tops on Aug. 27, are being published this week in two papers in the journal Science, as well as 44 papers in Geophysical Research Letters.

“We knew, going in, that Jupiter would throw us some curves,” said Scott Bolton, Juno principal investigator from the Southwest Research Institute in San Antonio. “But now that we are here we are finding that Jupiter can throw the heat, as well as knuckleballs and sliders. There is so much going on here that we didn’t expect that we have had to take a step back and begin to rethink of this as a whole new Jupiter.”

Among the findings that challenge assumptions are those provided by Juno’s imager, JunoCam. The images show both of Jupiter's poles are covered in Earth-sized swirling storms that are densely clustered and rubbing together.

“We're puzzled as to how they could be formed, how stable the configuration is, and why Jupiter’s north pole doesn't look like the south pole,” said Bolton. “We're questioning whether this is a dynamic system, and are we seeing just one stage, and over the next year, we're going to watch it disappear, or is this a stable configuration and these storms are circulating around one another?”

Another surprise comes from Juno’s Microwave Radiometer (MWR), which samples the thermal microwave radiation from Jupiter’s atmosphere, from the top of the ammonia clouds to deep within its atmosphere. The MWR data indicates that Jupiter’s iconic belts and zones are mysterious, with the belt near the equator penetrating all the way down, while the belts and zones at other latitudes seem to evolve to other structures. The data suggest the ammonia is quite variable and continues to increase as far down as we can see with MWR, which is a few hundred miles or kilometers. 

Prior to the Juno mission, it was known that Jupiter had the most intense magnetic field in the solar system. Measurements of the massive planet’s magnetosphere, from Juno’s magnetometer investigation (MAG), indicate that Jupiter’s magnetic field is even stronger than models expected, and more irregular in shape. MAG data indicates the magnetic field greatly exceeded expectations at 7.766 Gauss, about 10 times stronger than the strongest magnetic field found on Earth.

“Juno is giving us a view of the magnetic field close to Jupiter that we’ve never had before,” said Jack Connerney, Juno deputy principal investigator and the lead for the mission’s magnetic field investigation at NASA's Goddard Space Flight Center in Greenbelt, Maryland. “Already we see that the magnetic field looks lumpy: it is stronger in some places and weaker in others. This uneven distribution suggests that the field might be generated by dynamo action closer to the surface, above the layer of metallic hydrogen. Every flyby we execute gets us closer to determining where and how Jupiter’s dynamo works.”
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Mining the moon for rocket fuel to get us to Mars

Mining the moon for rocket fuel to get us to Mars | Amazing Science | Scoop.it

Forty-five years have passed since humans last set foot on an extraterrestrial body. Now, the moon is back at the center of efforts not only to explore space, but to create a permanent, independent space-faring society.

 

Planning expeditions to Earth's nearest celestial neighbor is no longer just a NASA effort, though the U.S. space agency has plans for a moon-orbiting space station that would serve as a staging ground for Mars missions in the early 2030s. The United Launch Alliance, a joint venture between Lockheed Martin and Boeing, is planning a lunar fueling station for spacecraft, capable of supporting 1,000 people living in space within 30 years.

 

Billionaires Elon Musk, Jeff Bezos and Robert Bigelow all have companies aiming to deliver people or goods to the moon. Several teams competing for a share of Google's US$30 million cash prize are planning to launch rovers to the moon. Groups of students from around the world recently participated in the 2017 Caltech Space Challenge, proposing designs of what a lunar launch and supply station for deep space missions might look like, and how it would work.

 

Right now all space missions are based on, and launched from, Earth. But Earth's gravitational pull is strong. To get into orbit, a rocket has to be traveling 11 kilometers a second – 25,000 miles per hour!

 

Any rocket leaving Earth has to carry all the fuel it will ever use to get to its destination and, if needed, back again. That fuel is heavy – and getting it moving at such high speeds takes a lot of energy. If we could refuel in orbit, that launch energy could lift more people or cargo or scientific equipment into orbit. Then the spacecraft could refuel in space, where Earth's gravity is less powerful.

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Massive galaxy clusters: The final frontier of the Frontier Fields

Massive galaxy clusters: The final frontier of the Frontier Fields | Amazing Science | Scoop.it

The NASA/ESA Hubble Telescope has peered across six billion light years of space to resolve extremely faint features of the galaxy cluster Abell 370 that have not been seen before. Imaged here in stunning detail, Abell 370 is part of the Frontier Fields program which uses massive galaxy clusters to study the mysteries of dark matter and the very early Universe.

 

Six billion light-years away in the constellation Cetus (the Sea Monster), Abell 370 is made up of hundreds of galaxies [1]. Already in the mid-1980s higher-resolution images of the cluster showed that the giant luminous arc in the lower left of the image was not a curious structure within the cluster, but rather an astrophysical phenomenon: the gravitationally lensed image of a galaxy twice as far away as the cluster itself. Hubble helped show that this arc is composed of two distorted images of an ordinary spiral galaxy that just happens to lie behind the cluster.

 

Abell 370's enormous gravitational influence warps the shape of spacetime around it, causing the light of background galaxies to spread out along multiple paths and appear both distorted and magnified. The effect can be seen as a series of streaks and arcs curving around the centre of the image. Massive galaxy clusters can therefore act like natural telescopes, giving astronomers a close-up view of the very distant galaxies behind the cluster – a glimpse of the Universe in its infancy, only a few hundred million years after the Big Bang.

 

This image of Abell 370 was captured as part of the Frontier Fields program, which used a whopping 630 hours of Hubble observing time, over 560 orbits of the Earth. Six clusters of galaxies were imaged in exquisite detail, including Abell 370 which was the very last one to be finished. An earlier image of this object – using less observation time and therefore not recording such faint detail – was published in 2009.

 

During the cluster observations, Hubble also looked at six "parallel fields", regions near the galaxy clusters which were imaged with the same exposure times as the clusters themselves. Each cluster and parallel field were imaged in infrared light by the Wide Field Camera 3 (WFC3), and in visible light by the Advanced Camera for Surveys (ACS).

 

The Frontier Fields programme produced the deepest observations ever made of galaxy clusters and the magnified galaxies behind them. These observations are helping astronomers understand how stars and galaxies emerged out of the dark ages of the Universe, when space was dark, opaque, and filled with hydrogen.

 

Studying massive galaxy clusters like Abell 370 also helps with measuring the distribution of normal matter and dark matter within such clusters [heic1506]. By studying its lensing properties, astronomers have determined that Abell 370 contains two large, separate clumps of dark matter, contributing to the evidence that this massive galaxy cluster is actually the result of two smaller clusters merging together.

 

Now that the observations for the Frontier Fields program are complete, astronomers can use the full dataset to explore the clusters, their gravitational lensing effects and the magnified galaxies from the early Universe in full detail.

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Christopher Chilvers's curator insight, May 21, 1:56 AM
Studying a galactic cluster 6 billion light years away and how it creates a gravitational lens for a spiral galaxy behind it.
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Epsilon Eridani bears striking resemblance to our own solar system

Epsilon Eridani bears striking resemblance to our own solar system | Amazing Science | Scoop.it
A team of University of Arizona researchers led by Kate Su have used NASA's Stratospheric Observatory for Infrared Astronomy (SOFIA) flying observatory to take a closer look at a system 10.5 light years away and discovered it has a familiar general structure.

 

Located 10.5 light-years away in the southern hemisphere of the constellation Eridanus, the star Epsilon Eridani, eps Eri for short, is the closest planetary system around a star similar to the early sun. It is a prime location to research how planets form around stars like our sun, and is also the storied location of the Babylon 5 space station in the science fictional television series of the same name.

 

Previous studies indicate that eps Eri has a debris disk, which is the name astronomers give to leftover material still orbiting a star after planetary construction has completed. The debris can take the form of gas and dust, as well as small rocky and icy bodies. Debris disks can be broad, continuous disks or concentrated into belts of debris, similar to our solar system’s asteroid belt and the Kuiper Belt – the region beyond Neptune where hundreds of thousands of icy-rocky objects reside. Furthermore, careful measurements of the motion of eps Eri indicates that a planet with nearly the same mass as Jupiter circles the star at a distance comparable to Jupiter’s distance from the Sun.

 

With the new SOFIA images, Kate Su of the University of Arizona and her research team were able to distinguish between two theoretical models of the location of warm debris, such as dust and gas, in the eps Eri system. These models were based on prior data obtained with NASA’s Spitzer space telescope.

 

One model indicates that warm material is in two narrow rings of debris, which would correspond respectively to the positions of the asteroid belt and the orbit of Uranus in our solar system. Using this model, theorists indicate that the largest planet in a planetary system might normally be associated with an adjacent debris belt.

 

The other model attributes the warm material to dust originating in the outer Kuiper-Belt-like zone and filling in a disk of debris toward the central star. In this model, the warm material is in a broad disk, and is not concentrated into asteroid belt-like rings nor is it associated with any planets in the inner region.

 

Using SOFIA, Su and her team ascertained that the warm material around eps Eri is in fact arranged like the first model suggests; it is in at least one narrow belt rather than in a broad continuous disk.

 

These observations were possible because SOFIA has a larger telescope diameter than Spitzer, 100 inches (2.5 meters) in diameter compared to Spitzer’s 33.5 inches (0.85 meters), which allowed the team onboard SOFIA to discern details that are three times smaller than what could be seen with Spitzer. Additionally, SOFIA’s powerful mid-infrared camera called FORCAST, the Faint Object infraRed CAmera for the SOFIA Telescope, allowed the team to study the strongest infrared emission from the warm material around eps Eri, at wavelengths between 25-40 microns, which are undetectable by ground-based observatories.

 

“The high spatial resolution of SOFIA combined with the unique wavelength coverage and impressive dynamic range of the FORCAST camera allowed us to resolve the warm emission around eps Eri, confirming the model that located the warm material near the Jovian planet’s orbit,” said Su. “Furthermore, a planetary mass object is needed to stop the sheet of dust from the outer zone, similar to Neptune’s role in our solar system. It really is impressive how eps Eri, a much younger version of our solar system, is put together like ours.”

 

This study was published in the Astronomical Journal on April 25, 2017.


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Epsilon Eridani system found to have structure quite similar to the Solar System.
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Astronomers detect dozens of new quasars and galaxies

Astronomers detect dozens of new quasars and galaxies | Amazing Science | Scoop.it

A team of astronomers led by Yoshiki Matsuoka of the National Astronomical Observatory of Japan (NAOJ) has detected a treasure trove of new high-redshift quasars (or quasi-stellar objects) and luminous galaxies. The newly found objects could be very important for our understanding of the early universe. The findings were presented Apr. 19 in a paper published on arXiv.org.

 

High-redshift quasars and galaxies (at redshift higher than 5.0) are useful probes of the early universe in many respects. They offer essential clues on the evolution of the intergalactic medium, quasar evolution, early supermassive black hole growth, as well as evolution of galaxies through cosmic times. Generally speaking, they enable scientists to study the universe when it looked much different than it does today.

 

Recently, Matsuoka's team has presented the results from the Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs) project, which uses multi-band photometry data provided by the Hyper Suprime-Cam (HSC) Subaru Strategic Program (SSP) survey. HSC is a wide-field camera installed on the Subaru 8.2 m telescope located at the summit of Maunakea, Hawaii and operated by NAOJ. The researchers selected nearly 50 photometric candidates from the HSC-SSP source catalog and then observed them with spectrographs on the Subaru Telescope and the Gran Telescopio Canarias (GTC), located on the island on the Canary Island of La Palma, Spain.

 

The observations resulted in the identification of 24 new quasars and eight new luminous galaxies at redshift between 5.7 and 6.8.

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Breakthrough Listen Search for Intelligent Life: First Results from 1709 Stars

Breakthrough Listen Search for Intelligent Life: First Results from 1709 Stars | Amazing Science | Scoop.it

Breakthrough Listen — the largest ever research program aimed at finding evidence of intelligent life beyond Earth — has released its eleven events ranked highest for significance as well as summary data analysis results.

 

The Breakthrough Listen project, announced in 2015, is currently using the Green Bank Telescope in West Virginia, the Automated Planet Finder optical telescope at Lick Observatory and the Parkes Telescope in Australia, with plans to incorporate other large telescopes around the world. The Breakthrough Listen science team has so far acquired several petabytes of data — available at breakthroughinitiatives.org — using these telescopes.

 

The researchers designed and built an analysis pipeline that scans through billions of radio channels in a search for unique signals from extraterrestrial civilizations. “The basics of searching for signatures of extraterrestrial technology are quite simple,” the scientists explained.

 

“Artificial signals can be distinguished from natural processes through features like narrow bandwidth; irregular spectral behavior, pulsing, or modulation patterns; as well as broad-band signals with unusual characteristics.”

 

“However, human technology emits signals similar to the ones being searched for. This means that algorithms must be designed to ensure that signals are coming from a fixed point relative to the stars or other targets being observed, and not from local interferers.”

 

The initial results from deploying the pipeline on the first year of Breakthrough Listen data taken with the 100-m Green Bank Telescope have been submitted for publication in the Astrophysical Journal. “With the submission of this paper, the first scientific results from Breakthrough Listen are now available for the world to review,” said Dr. Andrew Siemion, an astrophysicist and Director of the Berkeley SETI Research Center.

 

“Although the search has not yet detected a convincing signal from extraterrestrial intelligence, these are early days.”

Dr. Siemion and co-authors examined data on 692 stars, consisting of three 5-min observations per star, interspersed with 5-min observations of a set of secondary targets.

 

The total number of Breakthrough Listen target stars, described by Isaacson et al in a recent paper in the Publications of the Astronomical Society of the Pacific (arXiv.org preprint), is 1709.

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The final chapter in a remarkable mission of exploration and discovery: Cassini's Grand Finale

The final chapter in a remarkable mission of exploration and discovery: Cassini's Grand Finale | Amazing Science | Scoop.it
Cassini is one of the most ambitious efforts in planetary space exploration. A joint endeavour of NASA, ESA and the Italian space agency, Cassini is a sophisticated spacecraft exploring the Saturnian system since 2004.

 

The final chapter in a remarkable mission of exploration and discovery, Cassini's Grand Finale is in many ways like a brand new mission. Twenty-two times, NASA's Cassini spacecraft will dive through the unexplored space between Saturn and its rings. What we learn from these ultra-close passes over the planet could be some of the most exciting revelations ever returned by the long-lived spacecraft. This animated video tells the story of Cassini's final, daring assignment and looks back at what the mission has accomplished.

For more about the making of this video, including the science behind the imagery, see the feature at https://saturn.jpl.nasa.gov

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Scientists identify a black hole choking on stardust

Scientists identify a black hole choking on stardust | Amazing Science | Scoop.it

In the center of a distant galaxy, almost 300 million light years from Earth, scientists have discovered a supermassive black hole that is “choking” on a sudden influx of stellar debris.

 

In a paper published today in Astrophysical Journal Letters, researchers from MIT, NASA’s Goddard Space Flight Center, and elsewhere report on a “tidal disruption flare” — a dramatic burst of electromagnetic activity that occurs when a black hole obliterates a nearby star. The flare was first discovered on Nov. 11, 2014, and scientists have since trained a variety of telescopes on the event to learn more about how black holes grow and evolve.

 

The MIT-led team looked through data collected by two different telescopes and identified a curious pattern in the energy emitted by the flare: As the obliterated star’s dust fell into the black hole, the researchers observed small fluctuations in the optical and ultraviolet (UV) bands of the electromagnetic spectrum. This very same pattern repeated itself 32 days later, this time in the X-ray band.

 

The researchers used simulations of the event performed by others to infer that such energy “echoes” were produced from the following scenario: As a star migrated close to the black hole, it was quickly ripped apart by the black hole’s gravitational energy. The resulting stellar debris, swirling ever closer to the black hole, collided with itself, giving off bursts of optical and UV light at the collision sites. As it was pulled further in, the colliding debris heated up, producing X-ray flares, in the same pattern as the optical bursts, just before the debris fell into the black hole.

 

“In essence, this black hole has not had much to feed on for a while, and suddenly along comes an unlucky star full of matter,” says Dheeraj Pasham, the paper’s first author and a postdoc in MIT’s Kavli Institute for Astrophysics and Space Research. “What we’re seeing is, this stellar material is not just continuously being fed onto the black hole, but it’s interacting with itself — stopping and going, stopping and going. This is telling us that the black hole is ‘choking’ on this sudden supply of stellar debris.”

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Exoplanet KELT9b breaks all heat records and is hotter than many stars

Exoplanet KELT9b breaks all heat records and is hotter than many stars | Amazing Science | Scoop.it

The planet KELT 9b is so hot — hotter than many stars — that it shatters gas giant temperature records, researchers report online June 5 in Nature. This Jupiter-like exoplanet revolves around a star just 650 light-years away, locked in an orbit that keeps one side always facing its star. With blistering temps hovering at about 4,300o Celsius, the atmosphere on KELT 9b’s dayside is over 700 degrees hotter than the previous record-holder — and hot enough that atoms cannot bind together to form molecules.

 

“It’s like a star-planet hybrid,” says Drake Deming, a planetary scientist at the University of Maryland in College Park who was not involved in the research. “A kind of object we’ve never seen before.”

 

KELT 9b also boasts an unusual orbit, traveling around the poles of its star, rather than the equator, once every 36 hours. And radiation from KELT 9b’s host star is so intense that it blows the planet’s atmosphere out like a comet tail — and may eventually strip it away completely.

 

The planet is so bizarre that it took scientists nearly three years to convince themselves it was real, says Scott Gaudi of Ohio State University. Deming suspects KELT 9b is “the tip of the iceberg” for an undiscovered population of scalding-hot gas giants.

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Scientists solve mystery of how most antimatter in the Milky Way forms

Scientists solve mystery of how most antimatter in the Milky Way forms | Amazing Science | Scoop.it

A team of international astrophysicists led by ANU has shown how most of the antimatter in the Milky Way forms.

Antimatter is material composed of the antiparticle partners of ordinary matter -- when antimatter meets with matter, they quickly annihilate each other to form a burst of energy in the form of gamma-rays.

 

Scientists have known since the early 1970s that the inner parts of the Milky Way galaxy are a strong source of gamma-rays, indicating the existence of antimatter, but there had been no settled view on where the antimatter came from. ANU researcher Dr Roland Crocker said the team had shown that the cause was a series of weak supernova explosions over millions of years, each created by the convergence of two white dwarfs which are ultra-compact remnants of stars no larger than two suns.

 

"Our research provides new insight into a part of the Milky Way where we find some of the oldest stars in our galaxy," said Dr Crocker from the ANU Research School of Astronomy and Astrophysics.

 

Dr Crocker said the team had ruled out the supermassive black hole at the centre of the Milky Way and the still-mysterious dark matter as being the sources of the antimatter. He said the antimatter came from a system where two white dwarfs form a binary system and collide with each other. The smaller of the binary stars loses mass to the larger star and ends its life as a helium white dwarf, while the larger star ends as a carbon-oxygen white dwarf.

 

"The binary system is granted one final moment of extreme drama: as the white dwarfs orbit each other, the system loses energy to gravitational waves causing them to spiral closer and closer to each other," Dr Crocker said.

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NASA invites scientists to submit ideas for successful Europa lander

NASA invites scientists to submit ideas for successful Europa lander | Amazing Science | Scoop.it

Now is the time to voice your opinions on the lander’s instruments. NASA recently informed the science community to prepare for a planned competition to select science instruments for a potential Europa lander. While a Europa lander mission is not yet approved by NASA, the agency's Planetary Science Division has funding in Fiscal Year 2017 to conduct the announcement of opportunity process. "The possibility of placing a lander on the surface of this intriguing icy moon, touching and exploring a world that might harbor life is at the heart of the Europa lander mission," said Thomas Zurbuchen, associate administrator of NASA's Science Mission Directorate in Washington. "We want the community to be prepared for this announcement of opportunity, because NASA recognizes the immense amount of work involved in preparing proposals for this potential future exploration."

 

The community announcement provides advance notice of NASA's plan to hold a competition for instrument investigations for a potential Europa lander mission. Proposed investigations will be evaluated and selected through a two-step competitive process to fund development of a variety of relevant instruments and then to ensure the instruments are compatible with the mission concept. Approximately 10 proposals may be selected to proceed into a competitive Phase A. The Phase A concept study will be limited to approximately 12 months with a $1.5 million budget per investigation. At the conclusion of these studies, NASA may select some of these concepts to complete Phase A and subsequent mission phases.

 

Investigations will be limited to those addressing the following science objectives, which are listed in order of decreasing priority:

  • Search for evidence of life on Europa
  • Assess the habitability of Europa via in situ techniques uniquely available to a lander mission
  • Characterize surface and subsurface properties at the scale of the lander

 

In early 2016, in response to a congressional directive, NASA's Planetary Science Division began a study to assess the science and engineering design of a future Europa lander mission. NASA routinely conducts such studies—known as Science Definition Team (SDT) reports—long before the start of any mission to gain an understanding of the challenges, feasibility and science value of the potential mission. The 21-member team began work almost one year ago. The agency briefed the community on the Europa Lander SDT study at recent town halls at the 2017 Lunar and Planetary Science Conference (LPSC) at The Woodlands, Texas, and the Astrobiology Science Conference (AbSciCon) in Mesa, Arizona.

 

The proposed Europa lander is separate from and would follow its predecessor—the Europa Clipper multiple flyby mission - which now is in preliminary design phase and planned for launch in the early 2020s. Arriving in the Jupiter system after a journey of several years, the spacecraft would orbit the planet about every two weeks, providing opportunities for 40 to 45 flybys in the prime mission. The Clipper spacecraft would image Europa's icy surface at high resolution, and investigate its composition and structure of its interior and icy shell.

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Methanol detected for first time around young star

Methanol detected for first time around young star | Amazing Science | Scoop.it
Methanol, a key building block for the complex organic compounds that comprise life, has been detected for the first time in the protoplanetary disk of a young, distant star. This finding could help scientists better understand the chemistry occurring during a planet's formation that could ultimately lead to the emergence of life.

Scientists made the methanol discovery around TW Hydrae, a star about 80 percent of our sun's mass and roughly 5 million to 10 million years old. It represents a younger version of what our solar system may have looked like during its formation more than 4 billion years ago. At about 170 light-years away, TW Hydrae has the closest protoplanetary disk to Earth.

The methanol appears to be located in a ring peaking 30 astronomical units from the star. (An astronomical unit, or AU, is the average distance between Earth and the sun, or about 93 million miles.)

This methanol gas likely came from methanol ice located slightly further away from the star. The scientists detailed their findings in the paper, "First detection of gas-phase methanol in a protoplanetary disk," published the journal Astrophysical Journal Letters.

"Methanol is an important molecule because it has been shown in laboratory ice experiments to be a feedstock of larger and more complex molecules," said study lead author Catherine Walsh, an astrochemist at the University of Leeds in England. "The successful detection of methanol in a protoplanetary disk provides compelling evidence that larger molecules are also present."

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Research increases distance at which supernovas could spark mass extinctions on Earth

Research increases distance at which supernovas could spark mass extinctions on Earth | Amazing Science | Scoop.it

In 2016, researchers published “slam dunk” evidence, based on iron-60 isotopes in ancient seabed, that supernovae buffeted the Earth — one of them about 2.6 million years ago. University of Kansas researcher Adrian Melott, professor of physics and astronomy, supported those findings in Nature with an associated letter, titled “Supernovae in the neighborhood.”

 

Melott has followed up since those findings with an examination of the effects of the supernovae on Earth’s biology. In new research to appear in Astrophysical Journal, the KU researcher and colleagues argue the estimated distance of the supernova thought to have occurred roughly 2.6 million years ago should be cut in half.  

 

“There’s even more evidence of that supernova now,” he said. “The timing estimates are still not exact, but the thing that changed to cause us to write this paper is the distance. We did this computation because other people did work that made a revised distance estimate, which cut the distance in half. But now, our distance estimate is more like 150 light years.” A supernova exploding at such a range probably wouldn’t touch off mass extinctions on Earth, Melott said.  

 

“People estimated the ‘kill zone’ for a supernova in a paper in 2003, and they came up with about 25 light years from Earth,” he said. “Now we think maybe it’s a bit greater than that. They left some effects out or didn’t have good numbers, so now we think it may be a bit larger distance. We don’t know precisely, and of course it wouldn’t be a hard-cutoff distance. It would be a gradual change. But we think something more like 40 or 50 light years. So, an event at 150 light years should have some effects here but not set off a mass extinction.”

 

In addition to its distance, interstellar conditions at the time of a supernova would influence its lethality to biology on Earth. “Cosmic rays like to travel along magnetic field lines,” Melott said. “They don’t like to cut across magnetic field lines as they experience forces to stop them from doing that. If there’s a magnetic field, we don’t know its orientation, so it can either create a superhighway for cosmic ray, or it could block them.

 

The main interesting case did not assume the superhighway. It assumed that much of the magnetic field was blasted out by a series of supernovae, which made the Local Bubble — and we and the most recent supernovae were inside. This is a weak, disordered magnetic field. The best analogy I can think of is more like off-road driving.” In such a case, the authors think cosmic rays from the supernova at 150 light years would have penetrated to Earth’s lower atmosphere. 

 

“This is a much stronger thing,” he said. “The cosmic rays from the supernova would be getting down into the lower atmosphere — having an effect on the troposphere. All kinds of elementary particles are penetrating from altitudes of 45-10 miles, and many muons get to the ground. The effect of the muons is greater — it’s not overwhelming, but imagine every organism on Earth gets the equivalent of several CT scans per year. CT scans have some danger associated with them. Your doctor wouldn’t recommend a CT scan unless you really needed it.” 

 

Melott said cancer and mutations would be the most obvious consequences for Earth’s biology of a supernova’s cosmic rays. With his co-authors —  B.C. Thomas of Washburn University (2005 KU physics doctoral graduate and recent winner of the A. Roy Myers Excellence in Research Award), M. Kachelrieß of Institutt for fysikk in Norway, D.V. Semikoz of the Observatoire de Paris, Sorbonne Paris Cite in France and the National Research Nuclear University in Moscow, and A.C. Overholt (2013 KU physics doctoral graduate) of MidAmerica Nazarene University — Melott looked at the fossil record in Africa, the most geographically stable continent on earth during the Pleistocene, when a  supernova was likely to have occurred.

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Biggest ever simulations help to uncover the history of the galaxy

Biggest ever simulations help to uncover the history of the galaxy | Amazing Science | Scoop.it
The Royal Astronomical Society, encourages and promotes the study of astronomy, solar-system science, geophysics and closely related branches of science. The RAS organizes scientific meetings in Burlington House, its London HQ, and throughout the country, publishes international research and review journals, recognizes outstanding achievements by the award of medals and prizes, maintains an extensive library, supports education through grants and outreach activities and represents UK astronomy nationally and internationally.

 

Thousands of processors, terabytes of data, and months of computing time have helped a group of researchers in Germany create some of the largest and highest resolution simulations ever made of galaxies like our Milky Way. Led by Dr Robert Grand of the Heidelberger Institut fuer Theoretische Studien, the work of the Auriga Project appears in the journal Monthly Notices of the Royal Astronomical Society.

 

A composite of images from the simulation. (Left) Projected gas density of the galaxy environment about 10 billion years ago. Depicted are filamentary gas structures that feed the main galaxy at the centre. (Middle) Bird’s eye view of the gas disc in the present day. The fine detailed spiral pattern is clearly visible. (Right) Side-on view of the same gas disc in the present day. Cold gas is shown as blue, warm gas as green and hot gas as red.

 

Astronomers study our own and other galaxies with telescopes and simulations, in an effort to piece together their structure and history. Spiral galaxies like the Milky Way are thought to contain several hundred thousand million stars, as well as copious amounts of gas and dust. The spiral shape is commonplace, with a massive black hole at the centre, surrounded by a bulge of old stars, and arms winding outwards where relatively young stars like the Sun are found. However understanding how systems like our galaxy came into being continues to remain a key question in the history of the cosmos.

 

The enormous range of scales (stars, the building blocks of galaxies, are each about one trillion times smaller in mass than the galaxy they make up), as well as the complex physics involved, presents a formidable challenge for any computer model. Using the Hornet and SuperMUC supercomputers in Germany and a state-of-the-art code, the team ran 30 simulations at high resolution, and 6 at very high resolution, for several months.

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Massive Lava Waves Detected on Jupiter’s Moon Io

Massive Lava Waves Detected on Jupiter’s Moon Io | Amazing Science | Scoop.it
Io is the closest thing we have to hell in our Solar System, a Jovian moon that features hundreds of active volcanoes and expansive lakes filled with lava. New observations suggests that the largest of these lakes, Loki Patera, produces enormous waves that repeatedly flow around the molten surface.

 

Jupiter's moon Io has the biggest active volcano in the Solar System. Inside the volcano, a warm floor surrounds a cool central island. Previous observations have indicated that volcanic resurfacing occurs every one to three years, but telescope observations have insufficient resolution to see how this progresses, and spacecraft observations have not been able to see the entire floor at once. Katherine De Kleer et al. used an occultation of Io by another of Jupiter's moons (Europa) to map the entire floor at a spatial resolution of 2 kilometers, using interferometric telescope observations. They find that the resurfacing happens in two waves, with different starting times and velocities, which then converge around the central island. They interpret the differences between the waves as evidence of either a non-uniformity in the lava or variations in the bulk density of the crust across the volcano.

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Scientists Just Found a Completely New Kind of Symbiotic Relationship

Scientists Just Found a Completely New Kind of Symbiotic Relationship | Amazing Science | Scoop.it
In a scientific first, researchers have discovered a bizarre inter-species relationship in which salamanders and algae cozy up together to share cells. Scientists aren’t entirely sure why these two very different organisms have adopted such an intimate arrangement, but the discovery could represent a completely new form of symbiotic relationship.

Cell-within-cell arrangements between species are common in nature, but up until this point it’s only been seen in creatures like coral, clams, and insects. New research published in the science journal eLife describes the first known example of photo-cellular symbiosis involving the cells of a fully grown vertebrate animal, that is, an animal with a spinal column or backbone.

 

As a collaborative research team from the American Museum of Natural History and Gettysburg College revealed, the green alga Oophila amblystomatis makes its home inside of cells located across the body of the spotted salamander Ambystoma maculatum. The salamander doesn’t appear to be negatively affected by its microbial roommates, and in fact the amphibian may even be benefitting from this arrangement. The normally photosynthetic green algae, on the other hand, are completely stressed out, forced rely on an alternative means of energy production.

 

The finding is so strange and so unexpected that the scientists involved in the study aren’t sure why this relationship evolved in the first place, or how each creature might be benefitting. Intracellular “mutualists,” as they’re called, are extremely common in nature, where both parties benefit from the relationship. Examples include single-celled dinoflagellates that accumulate on coral and giant clams and use photosynthesis to provide sustenance to their hosts, and gut bacteria that helps bugs break down plant compounds.

 

Back in the late 19th century, biologists learned that green algae grows in the egg cases of spotted salamanders, providing a win-win situation for both; the embryos produce nitrogen-rich waste for the algae, and in turn, the algae increases the oxygen content found in the fluid around the breathing embryos through photosynthesis. For well over a century, scientists had assumed that this mutually-beneficial arrangement only occurred between the salamander embryo and the algae living outside it.

 

But the green algae is not limited to the egg cases—it’s also located inside cells of a mature salamander’s body. As previous research has shown, the algae enter the eggs, proliferate, and then later invades the tissues and cells of the developing embryos. Aside from the initial egg and algae symbiotic relationship, it wasn’t known if this subsequent arrangement incurred any kind of benefit, or if it was simply a residual or parasitic infection.


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Mystery Feature Remains: Changing Islands In Titan's Ligeia Mare

Mystery Feature Remains: Changing Islands In Titan's Ligeia Mare | Amazing Science | Scoop.it

These images from the Radar instrument aboard NASA's Cassini spacecraft show the evolution of a transient feature in the large hydrocarbon sea named Ligeia Mare on Saturn's moon Titan.

 

Analysis by Cassini scientists indicates that the bright features, informally known as the "magic island," are a phenomenon that changes over time. They conclude that the brightening is due to either waves, solids at or beneath the surface or bubbles, with waves thought to be the most likely explanation. They think tides, sea level and seafloor changes are unlikely to be responsible for the brightening.

 

The images in the column at left show the same region of Ligeia Mare as seen by Cassini's radar during flybys in (from top to bottom) 2007, 2013, 2014 and 2015.

 

The bottom image was acquired by Cassini on Jan. 11, 2015, and adds another snapshot in time as Cassini continues to monitor the ephemeral feature (previously highlighted in PIA18430). The feature is apparent in the images from 2013 and 2014, but it is not present in other images of the region.

 

Cassini has observed similar transient features elsewhere in Ligeia Mare, and also in Kraken Mare (see PIA19047). These features are the first instances of active processes in Titan's lakes and seas to be confirmed by multiple detections. Their changing nature demonstrates that Titan's seas are not stagnant, but rather, dynamic environments.

 

The Cassini radar team plans to re-observe this particular region of Ligeia Mare one more time during Cassini's final close flyby of Titan in April 2017. The results may further illuminate the phenomenon responsible for the appearance of the transient features.

 

The large image panel shows Ligeia Mare in its entirety. Ligeia is Titan's second-largest liquid hydrocarbon sea, and has a total area of about 50,000 square miles (130,000 square kilometers), making it 50 percent larger than Lake Superior on Earth. This panel is a mosaic of five synthetic aperture radar images acquired by Cassini between 2007 and 2014. It shows a region approximately 330 by 305 miles (530 by 490 kilometers) in area.

 

An earlier version of the mosaic was released as PIA17031; the new version includes new data to fill in some gaps in coverage and to improve the quality of coverage in some of the previously imaged areas.

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The arrhythmic beating of a black hole heart – Astronomy Now

The arrhythmic beating of a black hole heart – Astronomy Now | Amazing Science | Scoop.it

At the center of the Centaurus galaxy cluster, there is a large elliptical galaxy called NGC 4696. Deeper still, there is a supermassive black hole buried within the core of this galaxy.

New data from NASA’s Chandra X-ray Observatory and other telescopes has revealed details about this giant black hole, located some 145 million light years from Earth. Although the black hole itself is undetected, astronomers are learning about the impact it has on the galaxy it inhabits and the larger cluster around it.

 

In some ways, this black hole resembles a beating heart that pumps blood outward into the body via the arteries. Likewise, a black hole can inject material and energy into its host galaxy and beyond.

 

By examining the details of the X-ray data from Chandra, scientists have found evidence for repeated bursts of energetic particles in jets generated by the supermassive black hole at the center of NGC 4696. These bursts create vast cavities in the hot gas that fills the space between the galaxies in the cluster. The bursts also create shock waves, akin to sonic booms produced by high-speed airplanes, which travel tens of thousands of light years across the cluster.

 

The composite image shown contains X-ray data from Chandra (red) that reveals the hot gas in the cluster, and radio data from the NSF’s Karl G. Jansky Very Large Array (blue) that shows high-energy particles produced by the black hole-powered jets. Visible light data from the Hubble Space Telescope (green) show galaxies in the cluster as well as galaxies and stars outside the cluster.

 

Astronomers employed special processing to the X-ray data to emphasize nine cavities visible in the hot gas. These cavities are labeled A through I in an additional image, and the location of the black hole is labeled with a cross. The cavities that formed most recently are located nearest to the black hole, in particular the ones labeled A and B.

 

The researchers estimate that these black hole bursts, or “beats”, have occurred every five to ten million years. Besides the vastly differing time scales, these beats also differ from typical human heartbeats in not occurring at particularly regular intervals.

 

A different type of processing of the X-ray data reveals a sequence of curved and approximately equally spaced features in the hot gas. These may be caused by sound waves generated by the black hole’s repeated bursts. In a galaxy cluster, the hot gas that fills the cluster enables sound waves – albeit at frequencies far too low for the human hear to detect – to propagate.

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Hubble Spots Multiply-Imaged, Gravitationally Lensed Type Ia Supernova

Hubble Spots Multiply-Imaged, Gravitationally Lensed Type Ia Supernova | Amazing Science | Scoop.it

Type Ia supernovae always have the same intrinsic brightness, so by measuring how bright they appear astronomers can determine how far away they are.

 

Known as standard candles, these supernovae have been used for decades to measure distances across the Universe, and were also used to discover its accelerated expansion and infer the existence of dark energy.

 

“Resolving, for the first time, multiple images of a strongly lensed standard candle supernova is a major breakthrough,” said Prof. Ariel Goobar, from the Oskar Klein Centre at Stockholm University in Sweden.

 

“We can measure the light-focusing power of gravity more accurately than ever before, and probe physical scales that may have seemed out of reach until now.”

 

The newly-discovered supernova, called iPTF16geu, was first detected on September 5, 2016 by the intermediate Palomar Transient Factory (iPTF) collaboration with the Palomar Observatory.

 

Also known as SN 2016geu, the supernova exploded at a distance corresponding to a time 4.3 billion years ago. It could only be detected because a foreground galaxy — SDSS J210415.89-062024.7, which is 2.5 billion light-years away — lensed the light of the explosion, making it 52 times brighter for observers on Earth.

 

It also caused iPTF16geu to appear in four distinct places on the sky, surrounding the lensing galaxy in the foreground. The four images lie on a circle with a radius of only 3,000 light-years around the galaxy, making it one of the smallest extragalactic gravitational lenses discovered so far.

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NASA Missions Suggest New Shape of Sun-Galaxy Interaction

NASA Missions Suggest New Shape of Sun-Galaxy Interaction | Amazing Science | Scoop.it

New data from NASA’s Cassini mission, combined with measurements from the two Voyager spacecraft and NASA’s Interstellar Boundary Explorer, or IBEX, suggests that our sun and planets are surrounded by a giant, rounded system of magnetic field from the sun — calling into question the alternate view of the solar magnetic fields trailing behind the sun in the shape of a long comet tail.

 

The sun releases a constant outflow of magnetic solar material — called the solar wind — that fills the inner solar system, reaching far past the orbit of Neptune. This solar wind creates a bubble, some 23 billion miles across, called the heliosphere. Our entire solar system, including the heliosphere, moves through interstellar space.

 

The prevalent picture of the heliosphere was one of comet-shaped structure, with a rounded head and an extended tail. But new data covering an entire 11-year solar activity cycle show that may not be the case: the heliosphere may be rounded on both ends, making its shape almost spherical. A paper on these results was published in Nature Astronomy on April 24, 2017.

 

“Instead of a prolonged, comet-like tail, this rough bubble-shape of the heliosphere is due to the strong interstellar magnetic field — much stronger than what was anticipated in the past — combined with the fact that the ratio between particle pressure and magnetic pressure inside the heliosheath is high,” said Kostas Dialynas, a space scientist at the Academy of Athens in Greece and lead author on the study.

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