Daily Archives: May 11, 2017

Australias CSIRO faces fresh cuts in new spending plan.

By Cheryl JonesMay. 10, 2017 , 1:00 PM

In terms of the impact on science, the Australian budget, released 9 May, is very bland, says Les Field, science policy secretary at the Australian Academy of Science in Canberra, the nations leading scientific association. There are no big spending initiatives but no major cuts, he adds.

Its a business-as-usual budget for science and technology, agrees Kylie Walker, CEO of Science and Technology Australia in Canberra, which represents scientists.

Overall spending on science for the fiscal year beginning 1 July and in later years, called the forward estimates, is not yet clear becausesupport is spread across several ministries. But the plan does reveal some winners and losers.

Field notes that there will be small decreases in years to come for the publicly funded science agency, the Commonwealth Scientific and Industrial Research Organization (CSIRO), which in recent years has been hit with massive cuts that resulted in extensive job losses. Im profoundly disappointed at the missed opportunities to restore support, says Kim Carr, the opposition Australian Labor Partys shadow minister for innovation, industry, science, and research.

And the government is making it difficult for the private sector to pick up the slack. The budget cuts an R&D tax incentive by $810 million over the next 3 years, Carr notes. The incentive is one of the governments biggest programs to stimulate business investment in research and development. But the budget also includes an outlay of $74 million to promote innovation in Australias manufacturing sector, something Field welcomes.

Higher education is also suffering, says Belinda Robinson, chief executive of Universities Australia, an advocacy group based in Canberra. She was referring to $2 billion in cuts to higher education announced separately from the federal budget last Monday. Large numbers of overseas students make higher education the nations third-largest export sector. Universities contribute more than they receive, she says. And although the government plans to invest heavily in air, road, and rail transport infrastructure, it has cut a program designed to support big national research facilities at universities.

Astronomy, meanwhile, was a real policy win, Field says. The budget includes $19 million to support an Australian partnership with the European Southern Observatory, meaning Australian astronomers will be involved in the major astronomy initiatives around the world. The commitment also includes ongoing funding of $9 million a year over the next decade.

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Australian astronomy one of few winners in new budget | Science ... - Science Magazine

The Planet that Acts Like a Comet

Planets typically orbit their host stars in rounded ellipses, while comets follow long, narrow orbits that carry them far out into the cold reaches of the solar system before falling inward again. HD 20782bs orbit looks more like that of a comet than a giant planet twice as massive as Jupiter. The gas giant slingshots around a G-type main sequence star 117 light years away in the constellation Fornax, swooping in just 5.5 million miles from the star (seven times closer than Mercurys orbit of our Sun) before making a long swing 232 million miles out into its solar system (about the distance from the Sun to the Asteroid Belt). That gives HD 20782b an orbital eccentricity of 0.96: its path through space is a long, narrow ellipse, not the round, nearly circular kind that most well-behaved planets follow.

That wild orbit is probably thanks to a series of gravitational pushes from another gas giant orbiting the same star (which astronomers havent spotted yet), or possibly from the other star in its binary system, HD 20781. In fact, this is the first binary system astronomers have found where both stars have their own planets.

HD 20782b swoops past its star too fast for the stellar wind to blast away much of the gas giants atmosphere, so despite its daringly close perihelion, the planet still has clouds of icy particles, like the ones in Jupiters upper cloud layers. Starlight reflecting off those icy clouds allowed astronomers to learn more about the planet in 2016, ten years after changes in the stars radial velocity first revealed the planets existence.

A Planetary Family Feud

A long time ago in a solar system 1,200 light years away,, two gas giants collided and flung each other to the far ends of the solar system. CVSO 30b, detected in 2012, orbits the young M3 star CVSO 30 at just 1.2 million kilometers, a tiny fraction of the distance between Mercury and the Sun. Thats right on the edge of its Roche limit, the distance at which the stars gravity will start to rip the planet apart. In fact, CVSO 30b may already be close enough for its host star to start stripping away its mass. It takes just 11 hours for the gas giant to complete an orbit.

At the other end of the solar system, its sister planet CVSO 30c, detected in 2016, keeps its distance with a 99 billion kilometer orbital radius, taking 27,000 years to make a lap around the star. CVSO 30 is a fairly small star, less than half the mass of our Sun, so its unusual to find two super-sized gas giants caught in its gravitational pull. In fact, CVSO 30c is so large that its discoverers say its probably a type of brown dwarf, too large to be a proper planet and too small to become a star, hovering awkwardly on the threshold.

And given that the two planets are pretty close in mass (each is around 5 times as massive as Jupiter) their orbits shouldnt be so wildly different, according to most models of how solar systems form. In fact, this is the first solar system astronomers have ever seen in which two planets have such different orbits.

CVSO 30c probably didnt start its life so far from its parent star. In fact, it probably formed in a position more like the one Jupiter occupies in our own solar system, but at some point in the solar systems history, 30b and 30c interacted gravitationally and flung each other into their current extreme orbits, in what astronomers described in a 2016 paper as a mutual catastrophic event of planet-planet scattering. Its probably not stable in the long run but for purposes of astronomers here on Earth, its close enough. That gives astronomers a rare opportunity to study what happens when gas giants interact.

The system may not be what it appears, however. A 2015 paper suggested that CVSO 30b might not exist at all. If thats the case, CVSO 30c is so far out from CVSO 30 that it may not actually be orbiting the star at all. It could be a free-floating object in space, which isnt uncommon for objects of its mass and type. So far, astronomical observations havent been able to confirm that the giant planet and the nearby star are actually moving regularly in relation to one another, so its possible that theyre simply not. On the other hand, astronomers say thats highly unlikely, with odds on the order of .00002.

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The wild wild worlds: a guide to the weirdest planets in the Milky Way - Astronomy Magazine

On March 8, 2015, Jupiters moon Europa passed in front of Io, allowing detailed mapping of the bright volcanic crater called Loki Patera (upper left). Credit: Katherine de Kleer

Taking advantage of a rare orbital alignment between two of Jupiters moons, Io and Europa, researchers have obtained an exceptionally detailed map of the largest lava lake on Io, the most volcanically active body in the solar system.

On March 8, 2015, Europa passed in front of Io, gradually blocking out light from the volcanic moon. Because Europas surface is coated in water ice, it reflects very little sunlight at infrared wavelengths, allowing researchers to accurately isolate the heat emanating from volcanoes on Ios surface.

The infrared data showed that the surface temperature of Ios massive molten lake steadily increased from one end to the other, suggesting that the lava had overturned in two waves that each swept from west to east at about a kilometer (3,300 feet) per day.

Overturning lava is a popular explanation for the periodic brightening and dimming of the hot spot, called Loki Patera after the Norse god. (A patera is a bowl-shaped volcanic crater.) The most active volcanic site on Io, which itself is the most volcanically active body in the solar system, Loki Patera is about 200 kilometers (127 miles) across. The hot region of the patera has a surface area of 21,500 square kilometers, larger than Lake Ontario.

Earthbound astronomers first noticed Ios changing brightness in the 1970s, but only when the Voyager 1 and 2 spacecraft flew by in 1979 did it become clear that this was because of volcanic eruptions on the surface. Despite highly detailed images from NASAs Galileo mission in the late 1990s and early 2000s, astronomers continue to debate whether the brightenings at Loki Patera which occur every 400 to 600 days are due to overturning lava in a massive lava lake, or periodic eruptions that spread lava flows over a large area.

If Loki Patera is a sea of lava, it encompasses an area more than a million times that of a typical lava lake on Earth, said Katherine de Kleer, a UC Berkeley graduate student and the studys lead author. In this scenario, portions of cool crust sink, exposing the incandescent magma underneath and causing a brightening in the infrared.

This is the first useful map of the entire patera, said co-author Ashley Davies, of the Jet Propulsion Laboratory in Pasadena, who has studied Ios volcanoes for many years. It shows not one but two resurfacing waves sweeping around the patera. This is much more complex than what was previously thought.

This is a step forward in trying to understand volcanism on Io, which we have been observing for more than 15 years, and in particular the volcanic activity at Loki Patera, said Imke de Pater, a UC Berkeley professor of astronomy.

De Kleer is lead author of a paper reporting the new findings that will be published May 11 in the journal Nature.

Binocular telescope turns two eyes on Io

The images were obtained by the twin 8.4-meter (27.6-foot) mirrors of the Large Binocular Telescope Observatory in the mountains of southeast Arizona, linked together as an interferometer using advanced adaptive optics to remove atmospheric blurring. The facility is operated by an international consortium headquartered at the University of Arizona in Tucson.

Two years earlier, the LBTO had provided the first ground-based images of two separate hot spots within Loki Patera, thanks to the unique resolution offered by the interferometric use of LBT, which is equivalent to what a 23-meter (75-foot) telescope would provide, noted co-author and LBTO director Christian Veillet. This time, however, the exquisite resolution was achieved thanks to the observation of Loki Patera at the time of an occultation by Europa.

Europa took about 10 seconds to completely cover Loki Patera. There was so much infrared light available that we could slice the observations into one-eighth-second intervals during which the edge of Europa advanced only a few kilometers across Ios surface, said co-author Michael Skrutskie, of the University of Virginia, who led the development of the infrared camera used for this study. Loki was covered from one direction but revealed from another, just the arrangement needed to make a real map of the distribution of warm surface within the patera.

These observations gave the astronomers a two-dimensional thermal map of Loki Patera with a resolution better than 10 kilometers (6.25 miles), 10 times better than normally possible with the LBT Interferometer at this wavelength (4.5 microns). The temperature map revealed a smooth temperature variation across the surface of the lake, from about 270 Kelvin at the western end, where the overturning appeared to have started, to 330 Kelvin at the southeastern end, where the overturned lava was freshest and hottest.

Using information on the temperature and cooling rate of magma derived from studies of volcanoes on Earth, de Kleer was able to calculate how recently new magma had been exposed at the surface. The results between 180 and 230 days before the observations at the western end and 75 days before at the eastern agree with earlier data on the speed and timing of the overturn.

Interestingly, the overturning started at different times on two sides of a cool island in the center of the lake that has been there ever since Voyager photographed it in 1979.

The velocity of overturn is also different on the two sides of the island, which may have something to do with the composition of the magma or the amount of dissolved gas in bubbles in the magma, de Kleer said. There must be differences in the magma supply to the two halves of the patera, and whatever is triggering the start of overturn manages to trigger both halves at nearly the same time but not exactly. These results give us a glimpse into the complex plumbing system under Loki Patera.

Lava lakes like Loki Patera overturn because the cooling surface crust slowly thickens until it becomes denser than the underlying magma and sinks, pulling nearby crust with it in a wave that propagates across the surface. According to de Pater, as the crust breaks apart, magma may spurt up as fire fountains, akin to what has been seen in lava lakes on Earth, but on a smaller scale.

De Kleer and de Pater are eager to observe other Io occultations to verify their findings, but theyll have to wait until the next alignment in 2021. For now, de Kleer is happy that the interferometer linking the two telescopes, the adaptive optics on each and the unique occultation came together as planned that night two years ago.

We werent sure that such a complex observation was even going to work, she said, but we were all surprised and pleased that it did.

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[ 10 May 2017 ] Waves of lava seen in Io's largest volcanic crater News - Astronomy Now Online

This article originally appeared in the June 2014 issue of Astronomy.

Nearly 30 years ago, the worlds top radio telescope engineers and black-belt radio astronomers haggled over their requirements for an array of antennas that could investigate the deepest, darkest, and coldest places in the universe better than any other telescope ever made.

What they sought sounded like a starry-eyed wish list: 60 or more antennas able to survive blizzards and 100mph (160 km/h) winds yet also able move as fast as missile trackers. And thats not all. Their surfaces cannot deform more than a third the thickness of a human hair. Their electronics cant add noise to the data. Giant trucks must carry the antennas safely for miles across a high-altitude desert without dropping power to the cryogenic receivers. And the array wont work without a supercomputer that can perform 17 quadrillion operations every second.

Fast forward to 2014, and this seemingly fantastical telescope the Atacama Large Millimeter/submillimeter Array (ALMA) is complete. It is a leap in astronomical imaging akin to Galileo Galileis first use of a telescope, and similarly, its technology and early science have changed the business of astronomy forever. Achieving this marvel required the largest ground-based telescope partnership in history, an international collaboration between North America, Europe, East Asia, and Chile that collected $1.3 billion to design and build the worlds most complex astronomical instrument.

Engineering expectations

Radio telescopes gather light with wavelengths from fractions of a millimeter to hundreds of meters. Visible-light waves, by contrast, are only hundreds of nanometers long. Antenna size being equal, a radio telescopes ability to image the universe is to an optical telescopes capacity what finger-painting is to a color photograph.

To gather and focus enough radio waves to achieve similar or better resolution than their optical cousins, radio telescopes must be huge. Earths gravity limits the immensity of a single telescope, but ingenuity can counter that force.

The worlds most versatile radio telescopes are built as reconfigurable arrays of antennas, affording them maximum power and flexibility. Special-purpose supercomputers pair the data from each antenna with that from every other antenna across the array in some cases, up to thousands of miles away to create binocular images of the sky from many different perspectives. The farther apart two antennas are, the greater the resolution of their binocular vision. This groundbreaking technique is known as aperture synthesis and won a Nobel Prize for its pioneer, Sir Martin Ryle.

The resulting data provide often unequalled detail measurements that precisely reveal the spectra (emission of different wavelengths of light), shapes, positions, and distances of objects in space. ALMA, its 66 antennas spread a maximum distance of 9.9 miles (16 kilometers) apart, will have 10 times the resolution of the Hubble Space Telescope when the antennas are observing at their smallest wavelengths.

Unlike its shorter-wavelength cousins, such as Hubble, that collect light as energy packets that hit detectors and form pixels in an image, ALMA must process the light it collects as waves. Each ALMA antenna surface has been painstakingly hand-tuned to accurately reflect light waves as tiny as 400 micrometers long thats about the length a human hair grows in a day. If the dishes have bumps any larger than one-third the diameter of a human hair, then the cosmic waves are scattered away.

Also, submillimeter light waves crash into ALMAs receivers at frequencies as high as the terahertz range 1 trillion per second and no computer (yet) can handle a data stream like that. Therefore, all signals exiting ALMAs receivers have to be mixed with a longer carrier wave. A metronome-like device (called a local oscillator) sends this beat to each antenna.

To ensure these electronics do not introduce any signals of their own during the mix-down process (which electronics naturally do), engineers designed innovative, near-microscopic mixers that can be kept cryogenically cold. To reduce other noise, all eight receivers inside an ALMA antenna chill together in a giant thermos that contains 4-kelvin (452 Fahrenheit) liquid helium, which is bolted behind the dish. This technology has increased receiver sensitivity on Earth fourfold.

The antennas themselves are high-tech art in motion. Engineers from nearly every time zone on Earth came up with three different but equally elegant solutions to the ultimate 12-meter antenna wish list, and the array is an international family of these triplets. Although they look slightly different, ALMAs antennas all share the record-breaking capabilities that astronomers dreamed up 30 years ago.

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The newest big thing in radio astronomy - Astronomy Magazine

An artists conception of SIMP J013656.5+093347, or SIMP0136 for short, which the research team determined is a planetary like member of a 200-million-year-old group of stars called Carina-Near. Credit: NASA/JPL, slightly modified by Jonathan Gagn.

Sometimes a brown dwarf is actually a planet or planet-like anyway. A team led by Carnegies Jonathan Gagn, and including researchers from the Institute for Research on Exoplanets (iREx) at Universit de Montral, the American Museum of Natural History, and University of California San Diego, discovered that what astronomers had previously thought was one of the closest brown dwarfs to our own Sun is in fact a planetary mass object.

Their results are published by The Astrophysical Journal Letters.

Smaller than stars, but bigger than giant planets, brown dwarfs are too small to sustain the hydrogen fusion process that fuels stars and allows them to remain hot and bright for a long time. So after formation, brown dwarfs slowly cool down and contract over time. The contraction usually ends after a few hundred million years, although the cooling is continuous.

This means that the temperatures of brown dwarfs can range from as hot as stars to as cool as planets, depending on how old they are, said the AMNHs Jackie Faherty, a co-author on this discovery.

The team determined that a well-studied object known as SIMP J013656.5+093347, or SIMP0136 for short, is a planetary like member of a 200-million-year-old group of stars called Carina-Near.

Groups of similarly aged stars moving together through space are considered prime regions to search for free-floating planetary like objects, because they provide the only means of age-dating these cold and isolated worlds. Knowing the age, as well as the temperature, of a free-floating object like this is necessary to determine its mass.

Gagn and the research team were able to demonstrate that at about 13 times the mass of Jupiter, SIMP0136 is right at the boundary that separates brown dwarf-like properties, primarily the short-lived burning of deuterium in the objects core, from planet-like properties.

Free-floating planetary mass objects are valuable because they are very similar to gas giant exoplanets that orbit around stars, like our own solar systems Jupiter or Saturn, but it is comparatively much easier to study their atmospheres. Observing the atmospheres of exoplanets found within distant star systems is challenging, because dim light emitted by those orbiting exoplanets is overwhelmed by the brightness of their host stars, which blinds the instruments that astronomers use to characterize an exoplanets atmospheres.

The implication that the well-known SIMP0136 is actually more planet-like than we previously thought will help us to better understand the atmospheres of giant planets and how they evolve, Gagn said.

They may be easier to study in great detail, but these free-floating worlds are still extremely hard to discover unless scientists spend a lot of time observing them at the telescope, because they can be located anywhere in the sky and they are very hard to tell apart from brown dwarfs or very small stars. For this reason, researchers have confirmed only a handful of free-floating planetary like objects so far.

tienne Artigau, co-author and leader of the original SIMP0136 discovery, added: This newest addition to the very select club of free-floating planetary like objects is particularly remarkable, because we had already detected fast-evolving weather patterns on the surface of SIMP0136, back when we thought it was a brown dwarf.

In a field where analyzing exoplanet atmospheres is of the utmost interest, having already seen evidence of weather patterns on an easier-to-observe free-floating object that exists away from the brightness of its host star is an exciting realization.

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[ 9 May 2017 ] Surprise! When a brown dwarf is actually a planetary mass object News - Astronomy Now Online

Galaxy mergers are commonplace throughout the cosmos, building smaller galaxies into larger ones. And when galaxies merge, the supermassive black holes they contain are taken along for the ride. Such large-scale interactions can disrupt material orbiting in the vicinity of the black hole, causing changes in behavior and eventually turning up the accretion rate onto the black hole, creating an active galactic nucleus, or AGN.

Now, a recent study utilizing data from NASAs NuSTAR X-ray telescope has tracked merging galaxies and their black holes to show that during the later stages of this process, the black holes become cocooned in thick swaths of gas and dust, hiding them from the sight even as they gobble material at higher rates.

The study, published in the Monthly Notices of the Royal Astronomical Society, examined 52 supermassive black holes in nearby merging galaxies to determine how galaxies and their black holes grow together, especially during interactions such as mergers. While astronomers know that black holes grow rapidly as gas and dust fall into the singularity, there is still some uncertainty as to how this process is triggered.

Galaxy mergers in particular have often been cited as possible triggering events that could disrupt gas and dust at large distances from the black hole, funneling it into the center of the galaxy where it can lose enough energy to eventually fall into the growing black hole, rather than settle safely into orbit around it.

However, that material can also form a shroud around the black hole, making it more difficult to detect and study. The shroud is so thick that it blocks all but the most energetic light (such as high-energy X-rays) from escaping. Thus, the study was conducted with NuSTAR because of the telescopes sensitivity to high-energy X-rays, whereas other facilities, such as the Chandra X-ray Observatory, the Swift mission, and the X-ray Multi-Mirror Mission (XMM-Newton), are only sensitive to X-rays with lower energies. When high-energy X-rays are detected but low-energy X-rays are missing, astronomers know that the AGN is surrounded by a shell of thick material that isnt letting most of its emission escape.

By comparing the amount of high- and low-energy X-rays observed from their sample of AGN in merging galaxies, the group was able to determine that [t]he further along the merger is, the more enshrouded the AGN will be, explained lead author Claudio Ricci in a press release.

Galaxies that are far along in the merging process are completely covered in a cocoon of gas and dust. In fact, the AGN in the study that resided within galaxies in the later stages of merging (about half the sample) were about 95 percent enshrouded in dust, based on their X-ray emission.

While all active black holes are believed to have some amount of gas and dust in an obscuring torus around them, such a high percentage of obscuration in these particular AGN cant be explained solely by that torus, the authors stated in their study. Instead, it indicates that the galaxy merger has caused large amounts of gas and dust to move into the center of the galaxy, particularly when compared with isolated galaxies that arent undergoing mergers or have just begun to merge.

This study reinforces the idea that AGN tend to do most of their accreting during the later stages of a merger, and are heavily obscured during this time. Said Ricci, The results further our understanding of the mysterious origins of the relationship between a black hole and its host galaxy.

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Merging galaxies wrap their black holes in dusty shrouds ... - Astronomy Magazine