ESO ALMA Observatory: Young binary star system form planets with weird and wild orbits

This is ALMA data of HK Tau shown in a composite image with Hubble infrared and optical data. 

Credit: B. Saxton (NRAO/AUI/NSF); K. Stapelfeldt et al. (NASA/ESA Hubble)

Unlike our solitary Sun, most stars form in binary pairs, two stars that orbit a common center of mass.

Though remarkably plentiful, binaries pose a number of questions, including how and where planets form in such complex environments.

While surveying a series of binary stars with the Atacama Large Millimeter/submillimeter Array (ALMA), astronomers uncovered a striking pair of wildly misaligned planet-forming disks in the young binary star system HK Tau.

These results provide the clearest picture ever of proto-planetary disks around a double star and could reveal important details about the birth and eventual orbit of planets in a multiple star system.

"ALMA has given us an unprecedented view of a main star and its binary companion sporting mutually misaligned protoplanetary disks," said Eric Jensen, an astronomer at Swarthmore College in Pennsylvania.

"In fact, we may be seeing the formation of a solar system that may never settle down."

The two stars in this system, which is located approximately 450 light-years from Earth in the constellation Taurus, are less than 5 million years old and separated by about 58 billion kilometers, or 13 times the distance of Neptune from the Sun.

This system's companion star, dubbed HK Tau, appears fainter to astronomers on Earth because its disk of dust and gas blocks out much of the starlight.

The disk itself, however, can be easily observed by the starlight that it scatters at optical and near-infrared wavelengths.

The key velocity data taken with ALMA that helped the astronomers determine that the disks in HK Tau were misaligned. 

The red areas represent material moving away from Earth and the blue indicates material moving toward us. 

Credit: NASA/JPL-Caltech/R. Hurt (IPAC); ALMA (ESO/NAOJ/NRAO)

The disk around the main star, HK Tau A, is tilted in such a way that the light from its host star shines through unobscured, making it difficult for astronomers to see the disk optically.

This is not a problem for ALMA, however, which can readily detect the millimeter-wavelength light emitted by the dust and gas that comprise the disk.

With its unprecedented resolution and sensitivity, ALMA was able to fully resolve the rotation of HK Tau A's disk for the first time.

This clearer picture enabled the astronomers to calculate that the disks were misaligned, meaning they were out of sync with the orbit of their host stars, by as much as 60 degrees or more.

Rachel Akeson

"This clear misalignment has given us a remarkable look at a young binary star system," said Rachel Akeson of the NASA Exoplanet Science Institute (NEXSCI) at the California Institute of Technology in Pasadena, California.

"Though there have been hints before that this type of misaligned system exists, this is the cleanest and most striking example."

Stars and planets form out of vast clouds of dust and gas. As material in these clouds contracts under gravity, it begins to rotate until most of the dust and gas falls into a flattened proto-planetary disk swirling around a growing central protostar.

Despite forming from a flat, regular disk, planets can end up in highly eccentric orbits, and may be misaligned with the star's equator.

One theory for how planets can migrate to these unusual orbits is that a binary companion star can influence them, but only if its orbit is initially misaligned with the planets.

This is an artist's impression of the misaligned protoplanetary disks around the binary stars in HK Tau. 

Credit: R. Hurt (NASA/JPL-Caltech/IPAC)

"Our results demonstrate that the necessary conditions exist to modify planetary orbits and that these conditions are present at the time of planet formation, apparently due to the binary formation process," noted Jensen.

"We can't rule other theories out, but we can certainly rule in that a second star will do the job."

Since ALMA can see the otherwise invisible dust and gas of protoplanetary disks, it allowed for never-before-seen views of this young binary system.

"Because we're seeing this in the early stages of formation with the protoplanetary disks still in place, we can see better how things are oriented," noted Akeson. "You can simply see gas better than you can see planets."

Looking forward, the researchers want to determine if this type of system is typical or not. They note that this is a remarkable individual case, but additional surveys are needed to determine if this sort of arrangement is common throughout our Galaxy.

More information: Nature DOI: 10.1038/nature13521

NASA JWST NIRSpec: Next Generation Microshutter Array Technology

The image shows a close-up view of the next-generation microshutter arrays, designed to accommodate the needs of future observatories, during the fabrication process.

Image Credit: NASA/Bill Hrybyk

The microshutters are a new technology that was developed for the Webb telescope mission.

The microshutter device is a key component Webb's Near Infrared Spectrograph (NIRSpec).

NIRSpec is a powerful instrument that will record the spectra of light from distant objects.

The microshutter device only lets light in from selected objects to shine through NIRSpec.



NASA technologists have hurdled a number of significant challenges in their quest to improve a revolutionary observing technology originally created for the James Webb Space Telescope (JWST).

Determined to make the Webb telescope's microshutter technology more broadly available, a team of technologists at NASA's Goddard Space Flight Center spent the past four years experimenting with techniques to advance this capability.

James Webb Space Telescope (JWST) Mirror Array

One of the first things the team did was eliminate the magnet that sweeps over the shutter arrays to activate them, replacing it with electrostatic actuation.

Just as significant is the voltage needed to actuate the arrays.

By last year, the team had achieved a major milestone by activating the shutters with just 30 volts.

The team used atomic layer deposition, a state-of-the-art fabrication technology, to fully insulate the tiny space between the electrodes to eliminate potential electrical crosstalk that could interfere with the arrays’ operation.

They also applied a very thin anti-stiction coating to prevent the shutters from sticking when opened.

The "CanJam" manipulator allows a user to steer satellites using a wheel with three degrees of freedom, tilting forward and backward, swiveling left and right, and pivoting side to side.

Gyroscope-aided bikes and cars may one day rule the road but before the technology reaches the ground, a University at Buffalo research team will test similar equipment in outer space.

The Canfield joint actuation manipulator, nicknamed "CanJam" by the researchers, was selected by NASA to join the first commercial research flight on Virgin Galactic's SpaceShipTwo.

The tennis-ball sized device was designed by Manoranjan Majji, lead researcher and assistant professor in the Department of Mechanical and Aerospace Engineering.

"CanJam" can automatically control a satellite using a Canfield joint, a spherical joint that can point anywhere on a hemisphere, and an automated program that stabilizes the device when disturbed and a wheel.

The manipulator allows a user to steer satellites using a wheel with three degrees of freedom, tilting forward and backward, swiveling left and right and pivoting side to side.

Unlike traditional joints, the device also contains three motors as a failsafe in the chance one motor fails.

Traditional technologies used by NASA and other agencies occasionally don't produce the necessary torque to rotate aircrafts, also known as singularities, which make it difficult to build attitude control systems.

Due to its design, the "CanJam" system doesn't create singularities, simplifying attitude control, says Majji.

If the NASA test flight is successful, the Canfield joint actuation manipulator designed by Manoranjan Majji could be useful in directing the flight of satellites or helicopters by replacing the wheel with propellers. 

Credit: Douglas Levere

The UB project was chosen along with 11 other experiments through NASA's Flight Opportunities Program, which works with commercial companies, universities and government organizations to test innovative space technologies. NASA funded research and development of the designs.

"Projects like this enable us to build the next generation of agile space systems and aircraft," says Majji.

"In addition to aerospace systems, this technology has spill-over effects into the automobile industry. The future generation of cars and bikes are going to have control moment gyroscopes, and we're at the core of fundamental research that enables that sort of technology."

Majji's CanJam design was inspired by use of the Canfield joint in space thrusters. In his device, gyroscopic forces generated when the joint shifts create reaction torques that cause inverted satellite movement.

In the NASA flight test, once the spacecraft reaches microgravity, the device will point to a designated direction and a linear actuator will repeatedly push the manipulator out of place, destabilizing it.

The device will then automatically stabilise itself, correcting the pointing errors. Flight computers will record the accuracy of the manipulator after disturbances.

If successful, the manipulator could be useful for directing the flight of satellites or helicopters by replacing the wheel with propellers. Eventually, the technology will find its way onto cars and bikes, says Majji.

Research conducted through Majji's lab also focuses on designing aerospace vehicle sensors and actuators, and developing autopilot and tracking programs for unmanned aerial vehicles.

NASA's Messenger: Mercury's magnetic field reveals its interior is different from Earth's

Earth and Mercury are both rocky planets with iron cores, but Mercury's interior differs from Earth's in a way that explains why the planet has such a bizarre magnetic field, UCLA planetary physicists and colleagues report.

Measurements from NASA's Messenger spacecraft have revealed that Mercury's magnetic field is approximately three times stronger at its northern hemisphere than its southern one.

In the current research, scientists led by Hao Cao, a UCLA postdoctoral scholar working in the laboratory of Christopher T. Russell, created a model to show how the dynamics of Mercury's core contribute to this unusual phenomenon.

The magnetic fields that surround and shield many planets from the sun's energy-charged particles differ widely in strength.

While Earth's is powerful, Jupiter's is more than 12 times stronger, and Mercury has a rather weak magnetic field.

Venus likely has none at all. The magnetic fields of Earth, Jupiter and Saturn show very little difference between the planets' two hemispheres.

Within Earth's core, iron turns from a liquid to a solid at the inner boundary of the planet's liquid outer core; this results in a solid inner part and liquid outer part.

The solid inner core is growing, and this growth provides the energy that generates Earth's magnetic field. Many assumed, incorrectly, that Mercury would be similar.

"Hao's breakthrough is in understanding how Mercury is different from the Earth so we could understand Mercury's strongly hemispherical magnetic field," said Russell, a co-author of the research and a professor in the UCLA College's department of Earth, planetary and space sciences.

"We had figured out how the Earth works, and Mercury is another terrestrial, rocky planet with an iron core, so we thought it would work the same way but it's not working the same way."

Mercury's peculiar magnetic field provides evidence that iron turns from a liquid to a solid at the core's outer boundary, say the scientists, whose research currently appears online in the journal Geophysical Research Letters and will be published in an upcoming print edition.

"It's like a snow storm in which the snow formed at the top of the cloud and middle of the cloud and the bottom of the cloud too," said Russell.

"Our study of Mercury's magnetic field indicates iron is snowing throughout this fluid that is powering Mercury's magnetic field."

The research implies that planets have multiple ways of generating a magnetic field.

Hao and his colleagues conducted mathematical modeling of the processes that generate Mercury's magnetic field.

In creating the model, Hao considered many factors, including how fast Mercury rotates and the chemistry and complex motion of fluid inside the planet.

The cores of both Mercury and Earth contain light elements such as sulfur, in addition to iron; the presence of these light elements keeps the cores from being completely solid and "powers the active magnetic field–generation processes," Hao said.

Hao's model is consistent with data from Messenger and other research on Mercury and explains Mercury's asymmetric magnetic field in its hemispheres.

He said the first important step was to "abandon assumptions" that other scientists make.

"Planets are different from one another," said Hao, whose research is funded by a NASA fellowship. "They all have their individual character."

More Information: 'A dynamo explanation for Mercury's anomalous magnetic field.' Authors: Hao Cao, Christopher Russell, et al. - Article first published online: 19 JUN 2014 DOI: 10.1002/2014GL060196

Breathing Silk leaf maker claims material will aid space journeys - Video

Julian Melchiorri, a graduate of the Royal College of Art has developed a synthetic biological leaf.

Potential applications range from the material being used on buildings' facades, or even for support on space journeys for oxygen.

Julian Melchiorri said Silk Leaf, a man-made, biological leaf involves a material extracted directly from the fibers of silk.

Julian Melchiorri

Melchiorri said the synthetic biological leaf he developed, which absorbs water and carbon dioxide to produce oxygen, is like a real leaf, and could enable long-distance space travel, according to a report in Dezeen.

This material, he said, has an amazing property.

Choloroplast

"I extracted choloroplasts from plant cells, and placed them inside this silk material."

The material work and breathes as a leaf does. "It's very light…low energy-consuming." He also said, "My idea was to use the efficiency of nature in a man-made environment."

The synthetic leaf could, among other applications, be used to make long-distance space travel that much more imaginable.

The Dezeen report includes pictures of the leaf transformed into lighting and building applications.

He said he thought about applications on smaller and larger scales.

He imagined its being used as a free surface in interior design, or for outdoor applications.

"So facades, ventilation programs…You can soak up air from outdoors, pass it by way of these biological filters and then carry oxygenated air inside."

Artist Impression of Silk Leaf City

He also noted the leaf material may be applicable to space travel.

"NASA is researching different ways to produce oxygen for long-distance space journeys to let us live in space," he said.

"This material could allow us to explore space much further than we can now."

A CNET article called it "an oxygen factory for space travel."

Writing in CNET, Eric Mack brought the significance of the NASA idea to light in asking, "what if we could take those biological oxygen factories into space with us, but without all the land, sun, water, soil, and gravity that forests tend to require?"

The Silk Leaf project was developed by Melchiorri as part of the Royal College of Art's Innovation Design Engineering course in collaboration with Tufts University silk lab.

ESA Pharao space clock delivered to ISS - Video

ESA has welcomed the arrival of Pharao, an important part of ESA's atomic clock experiment that will be attached to the International Space Station in 2016.

Delivered by France's CNES space agency, Pharao is accurate to a second in 300 million years, which will allow scientists to test fundamental theories proposed by Albert Einstein with a precision that is impossible in laboratories on Earth.

Time is linked to gravity and, for example, passes faster at the top of Mount Everest than at sea level.

These effects have been proved in experiments on Earth but the Atomic Clock Ensemble in Space, ACES, will make more precise measurements as it flies 400 km high on humanity's weightless laboratory.

Comparing clocks under different gravity levels allows researchers to test Einstein's theories on space-time and other theories in fundamental physics.

To achieve its accurate timekeeping, the Pharao space clock uses lasers to cool caesium atoms down to -273 C, close to absolute zero.

Internet of clocks
Accurate timekeeping is vital for pinpointing our location, secure banking and fundamental science, but it is not easy to compare data from the many atomic clocks on Earth.

ACES is more than just one clock in space. Pharao will be accompanied by the Space Hydrogen Maser, which uses a different technique to keep track of time.

This clock uses hydrogen atoms as a frequency reference and offers better stability but for a shorter time.

By coupling the two clocks, ACES will provide the scientists with a unique, highly stable time reference in space.

The project will link together atomic clocks in Europe, USA, Japan and Australia with their space counterparts via microwave and optical links to create an 'internet of clocks' and to deliver precise timekeeping.

Connecting all these clocks is a significant part of ACES, with France's Cadmos User Support and Operations Centre taking responsibility for operating the instruments on the Station.

ESA astronaut Thomas Pesquet will be on the orbital outpost when ACES arrives in 2016. Using the Station's robotic arm, the 375 kg payload will be installed on a platform outside Europe's Columbus space laboratory.

Black holes exploding into 'white holes'

The collapse of a star into a black hole could be a temporary effect that leads to the formation of a 'white hole', suggests a new model based on a theory known as loop quantum gravity.

A new scientific theory suggests that when black holes reach the end of their lifespan, they explode into "white holes" and release all of their matter into space.

If true, the theory could help put to rest the debate over whether or not black holes actually destroy the matter they end up devouring.

As noted by Albert Einstein's theory of relativity, when a dying star ends up collapsing under its own weight, at some point the collapse becomes irreversible, resulting in a black hole that consumes light and anything else within its surrounding area.

Although black holes do slowly leak radiation over time, ultimately draining the black hole completely, this doesn't account for all the other matter that the dying star has consumed.

Since quantum theory does not allow for the possibility that information can be lost, though, two researchers from France's Aix-Marseille University believe they've discovered an explanation for this so-called "information paradox."

Carlo Rovelli

According to physicists Carlo Rovelli and Hal Haggard, a black hole eventually reaches a point where it cannot collapse any further and the internal pressure begins to push outwards.

This essentially turns the black hole inside out and expels everything it once consumed back into space.

Notably, the scientists believe that these white holes are created not long after the black hole's original formation, and we humans can't see it because gravity dilates time and makes the black hole's lifespan seem to last for billions or trillions of years.

Their current calculation is that it only takes a few thousandths of a second for a black hole to turn into a white hole.

Hal Haggard

Importantly, the process is very long seen from the outside, but is very short for a local observer at a small radius," the researchers wrote in a paper on the subject.

Ron Cowen, a science writer at Nature, explained further.

If the authors are correct, tiny black holes that formed during the very early history of the Universe would now be ready to pop off like firecrackers and might be detected as high-energy cosmic rays or other radiation.

In fact, they say, their work could imply that some of the dramatic flares commonly considered to be supernova explosions could in fact be the dying throes of tiny black holes that formed shortly after the Big Bang.

Although Rovelli and Haggard aren't completely dismissing the idea that black holes leak radiation, they said the trickles of energy would not be sufficient enough to deplete the dying stars of all the energy they've consumed.

Radiation may very well seep out, but their work is primarily concerned with discovering what happens inside a black hole.

Both Rovelli and Haggard admitted that their theory needs to be tested further with more comprehensive calculations.

If research confirms their ideas, however, theoretical physicist Steven Giddings of the University of California Santa Barbara says, "It would be important. Understanding how information escapes from a black hole is the key question for the quantum mechanics of black holes, and possibly for quantum gravity itself."

Theoretical physicist Stephen Hawking of the University of Cambridge, UK, has recently suggested that true event horizons would be incompatible with quantum physics.

More Information: Black hole fireworks: quantum-gravity effects outside the horizon spark black to white hole tunneling - Authors: Hal M. Haggard, Carlo Rovelli - arXiv:1407.0989