Scientists discover radio emissions are emanating from fireballs

These images show the sky above the first LWA station. 

Each image shows the full sky, down to the horizon at the image's edge.

Streaking across the sky at more than 50 kilometers per second at atmospheric heights of more than a 90 kilometers high, researchers using the first station of University of New Mexico’s Long Wavelength Array (LWA) saw something new that had never been seen before; something that could hold a treasure trove of new information in the world of physics.

Very Large Array (VLA)

The first station of the LWA, known as LWA1, is a unique telescope that consists of a collection of 256 dipoles combined into one massive array with a collective-area of a 100-meter dish.

The LWA1, is a highly sensitive telescope that can create images of the entire sky.

It allows researchers to keep eyes on the whole sky day and night, probing a relatively unexplored region of the electromagnetic spectrum.

Greg Taylor

Within six months of turning LWA1 on, UNM Department of Physics Professor Greg Taylor and his team got the all sky imaging up and running.

Shortly thereafter, they started to search for transients, brief pulses of radio waves coming from the sky.

Ken Obenberger, a UNM graduate student, and colleagues searched for transients in more than 11,000 hours of all-sky images from the LWA at frequencies between 25 and 75 MHz.

In this data he identified 49 long (30 seconds or longer) transients.

"We would see a bright source appear in the sky and it would last for about a minute, and then it would go away," Obenberger said.

"Most of them would come on at one point and then fade away. Sometimes they were a bit extended and a little bit resolved by the telescope, but oftentimes, they weren't," he added.

Long Wavelength Array (LWA)

The University of New Mexico’s Long Wavelength Array (LWA) with the Very Large Array (VLA) in the background.

The research team didn't know what they were exactly and that situation went on for several months.

"When we found an event that streaked over 90 degrees across the sky (see Figure 01 below) we asked ourselves, 'could these be fireballs?'" Taylor asked.

Fireballs are a class of meteor brighter than the planet Venus.

Figure 01: LWA1 image at 38 MHz of a rare fireball that streaked across the sky on Jan. 21, 2014 and left a glowing trail that lasted for over a minute. 

Emission from constant sources has been subtracted for clarity.

To investigate this possibility, the team utilized NASA's All Sky Fireball Network, an observatory consisting of 12 cameras located in the United States.

While most of the cameras are in other states, two are located in southern New Mexico.

The researchers compared the times and locations of the 49 transients with data from the Fireball Network.

They found that 10 of those transients corresponded both spatially and temporarily with fireballs. The optical always precedes the radio Obenberger says.

"You have this bright optical fireball, then slowly the radio emission ramps up. The show is over in the optical stage fairly quickly after a few seconds, but then we have this radio emission lasting for about a minute."

These detections suggest that fireballs emit a low frequency pulse, something that no other telescope has ever seen, and this discovery has provided researchers with new insight into the physics of meteors.

It'll be fun to learn more and it'll give us new information about meteors, their composition or something about the upper atmosphere. It's kind of a whole new ball game." Taylor explained.

More information: "Detection of Radio Emission from Fireballs." K.S. Obenberger, G.B. Taylor, J.M. Hartman, J. Dowell, S.W. Ellingson, J.F. Helmboldt, P.A. Henning, M. Kavic, F.K. Schinzel, J.H. Simonetti, K. Stovall, T.L. Wilson. arxiv.org/abs/1405.6772

A blast from its past dates the youngest neutron-star binary

The youngest member of an important class of objects in space has been found by a team that includes Penn State Distinguished Professor of Astronomy and Astrophysics Niel Brandt. 

This composite image shows the energies streaming toward Earth from this object -- X-rays in blue and the radio emission in purple.

These energy detections have been overlaid in this image on an optical field of view from the Digitized Sky Survey. 

This discovery allows scientists to study a critical phase after a supernova and the birth of a neutron star. 

Credit: X-ray: NASA/CXC /Univ. of Wisconsin-Madison /S. Heinz et al; Optical: DSS; Radio: CSIRO/ATNF/ATCA

X-rays streaming toward Earth from the region near a neutron star that is cannibalizing its companion star have revealed the pair to be the youngest "X-ray binary" yet known.

The discovery by a team that includes a Penn State astronomer is being published in this week's issue of the The Astrophysical Journal.

The team discovered the age of this record-breaking pair, named Circinus X-1, by using data from NASA's Chandra X-ray Observatory, which revealed faint remnants of the supernova explosion that created the neutron star.

"I have been perplexed by the unusually strong evolution of the orbit of Circinus X-1 since my graduate-school days," said Niel Brandt, Distinguished Professor of Astronomy and Astrophysics.

"The discovery now of this system's youth provides a satisfying explanation for why its orbit evolves so strongly—because the system likely still is settling down after its violent birth."

The research team, which was led by Sebastian Heinz at the University of Wisconsin-Madison, determined that Circinus X-1 is less than 4,600 years old.

"X-ray binaries provide us with opportunities to study matter under extreme conditions that would be impossible to recreate in a laboratory," Heinz said.

"For the first time, we can study a newly minted neutron star in an X-ray binary system."

This is an artist's conception of the life of X-ray binary systems and the young and turbulent history of Circinus X-1, which formed in a supernova explosion less than 4,600 years ago, approximately 500 B.C.E., making it the youngest known X-ray binary. 

Credit: University of Wisconsin-Madison

X-ray binaries are star systems made up of two parts: a compact stellar remnant—either a neutron star or a black hole; and a companion star—a normal star like our Sun.

The new discovery, made in parallel with a radio telescope in Australia, provides scientists with unique insight into the formation of neutron stars and supernovas, and the effect of the supernova's explosion on a nearby companion star.

As the two objects orbit one another, the neutron star or black hole pulls in gas from the companion star, heating the gas to millions of degrees, producing intense X-ray radiation, and making these star systems some of the brightest X-ray sources in the sky.

To determine the age of Circinus X-1, the astronomers needed to examine the material around the orbiting pair of stars.

However, the overwhelming brightness of the neutron star made it too difficult for researchers to observe that interstellar gas.

The team recently caught a break, however, when they observed the neutron star in a very faint state—dim enough for scientists to detect the X-rays from the supernova shock wave that plowed through the surrounding interstellar gas.

Read the full story here

Do Auroras Exist Outside our Solar System?

University of Leicester planetary scientists have found new evidence suggesting auroras -- similar to Earth's Aurora Borealis -- occur on bodies outside our solar system. 

Auroras occur on several planets within our solar system, and the brightest -- on Jupiter -- are 100 times brighter than those on Earth. 

However, no auroras have yet been observed beyond Neptune.

A new study led by University of Leicester lecturer Dr. Jonathan Nichols has shown that processes strikingly similar to those which power Jupiter's auroras could be responsible for radio emissions detected from a number of objects outside our solar system.

In addition, the radio emissions are powerful enough to be detectable across interstellar distances -- meaning that auroras could provide an effective way of observing new objects outside our solar system.

Auroras occur when charged particles in an object's magnetosphere collide with atoms in its upper atmosphere, causing them to glow.

However, before hitting the atmosphere, these particles also emit radio waves into space.

The study, "Origin of Electron Cyclotron Maser Induced Radio Emissions at Ultracool Dwarfs: Magnetosphere-Ionosphere Coupling Currents," which recently appeared in the Astrophysical Journal, shows that this phenomenon is not limited to our solar system.

It shows that the radio emissions from a number of ultracool dwarfs may be caused in a very similar, but significantly more powerful, way to Jupiter's auroras.

Dr. Nichols, a Lecturer and Research Fellow in the University of Leicester's Department of Physics and Astronomy, said: "We have recently shown that beefed-up versions of the auroral processes on Jupiter are able to account for the radio emissions observed from certain "ultracool dwarfs" -- bodies which comprise the very lowest mass stars -- and "brown dwarfs" -- 'failed stars' which lie in-between planets and stars in terms of mass.

"These results strongly suggest that auroras do occur on bodies outside our solar system, and the auroral radio emissions are powerful enough -- one hundred thousand times brighter than Jupiter's -- to be detectable across interstellar distances."

The paper, which also involved researchers at the Center for Space Physics, Boston University, USA, could have major implications for the detection of planets and objects outside our solar system which could not be discovered with other methods.

Hypertension treatment: The Future Solution is Simple, fast and safe

A new system can perform a one-time minimally invasive catheter-based percutaneous procedure that has shown to significantly reduce blood pressure–in as little as 30 seconds.

This new technology, developed by Vessix Vascular, has the potential to help the one in three adults in the United States who suffer from hypertension– a condition that is more common than cancer, diabetes and coronary artery disease combined.

Today, anti-hypertensive drugs are the primary treatment for hypertension. But despite the widespread use of drugs, only about half of hypertensive patients around the world are well controlled, even when multiple medications are taken at optimal dosages.

The V2 system perform a new procedural treatment called renal denervation, which Dr. Mehemet Oz has called “a profound game changer.” It uses a short blast of radiofrequency (RF) energy to disable the nerves surrounding the arteries leading to the kidneys, treating one of the key physiological contributors to hypertension.

The V2 Catheter is a balloon catheter with a unique configuration of RF electrodes mounted on its exterior, which makes the procedure faster and safer. It delivers precise temperature controlled RF energy from the V2 RF Generator to both renal arteries in 60 seconds, while the only other competatively marketed Renal Denervation system takes 50-60 minutes.

The rapidity of the V2 treatment promises to reduce patient discomfort as well as exposure to radiation for both the patient and the interventional cardiologist performing the procedure.

Photo courtesy: Vessix Vascular

Amateur Astronomer Captures Jupiter

Image Credit: NASA/Damian Peach

This image of Jupiter and its moons, icy Io and, the largest of Jupter's moons, Ganymede was acquired by amateur astronomer Damian Peach, when Jupiter was close to opposition. 

South is up and the "Great Red Spot" is visible in the image.

Ground-based astronomy will play a vital role in the success of NASA's Juno mission.

Because Jupiter has such a dynamic atmosphere, images from amateur astronomers will assist the JunoCam instrument team predict what features will be visible when the camera's images are taken.

With its suite of science instruments, the Juno spacecraft will investigate the existence of a solid planetary core, map the planet's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere and observe the planet's auroras.

Image credit: NASA/JPL

Juno's primary goal is to improve our understanding of Jupiter's formation and evolution.

The spacecraft will spend a year investigating the planet's origins, interior structure, deep atmosphere and magnetosphere.

Juno's study of Jupiter will help us to understand the history of our own solar system and provide new insight into how planetary systems form and develop in our galaxy and beyond.

Juno's principal investigator is Scott Bolton, Director of Southwest Research Institute in San Antonio, Texas. NASA's Jet Propulsion Laboratory in Pasadena, Calif., manages the mission.

Lockheed Martin Space Systems of Denver, Colo., is building the spacecraft. The Italian Space Agency, Rome, is contributing an infrared spectrometer instrument and a portion of the radio science experiment.

Cell Phone Jammers: A Convenience or a crime?

A cell phone jammer is a small device that looks like a walkie-talkie. It is used to prevent cell phones from receiving signals from base stations.

Cell phone jammers block cell phone operations by sending radio waves along the same frequencies that cellular phones use. The radio waves cause interference between the cell phone and its ability to communicate with cell phone towers.

Cell phone jammers come in a variety of sizes, can affect large or small radiuses, and can target a variety of cell phone bands (frequencies used to communicate with towers).

Jammers either disrupt phone-to-tower frequencies or tower-to-phone frequencies. The latter is typically more effective.

Cell phone jammers are illegal according to FCC regulations. The reason is because cell phone jammers could prohibit emergency vehicles from communicating with each other.

It can also disrupt police communication and jammers may prohibit someone from reaching emergency services if they're used incorrectly.

Venice: Curly Pasta shaped Radiowaves to solve congestion

A group of Italian and Swedish researchers appears to have solved the problem of radio congestion by cleverly twisting radio waves into the shape of fusilli pasta, allowing a potentially infinite number of channels to be broadcast and received.

the researchers have demonstrated this in real-life conditions by beaming two twisted radio waves across the waters of Venice.

Their results have been reported today, Friday 2 March, in the Institute of Physics and German Physical Society's New Journal of Physics and are accompanied by a video abstract that gives an excellent insight into the authors' work.

As the world continues to adapt in the digital age, the introduction of new mobile smartphones, wireless internet and digital TVs means the number of radio frequency bands available to broadcast information gets smaller and smaller.

"You just have to try sending a text message at midnight on New Year's Eve to realise how congested the bands are," said lead author Dr Fabrizio Tamburini.

The researchers, from the University of Padova, Italy, and the Angstrom Laboratory, Sweden, devised a solution to this by manipulating waves so that they can hold more than one channel of information.

In addition to increasing the quantity of information being passed around our planet, this new discovery could also help lend an insight into objects far out in our galaxy. Black holes, for example, are constantly rotating and as waves pass them, they are forced to twist in line with the black hole.

According to Tamburini, analysing the incoming waves from the supermassive black hole at the centre of the Milky Way, Sagittarius A, could help astronomers obtain crucial information about the rotation of this "million-solar mass monster."

More information: "Encoding many channels on the same frequency through radio vorticity: first experimental test" Tamburini F et al 2012 New J. Phys. 14 033001 - http://iopscience. … 3001/article

RXTE Helps Pinpoint Launch of Bullets in Black Hole Jet

Radio imaging by the Very Long Baseline Array (top row), combined with simultaneous X-ray observations by NASA's RXTE (middle), captured the transient ejection of massive gas "bullets" by the black hole binary H1743-322 during its 2009 outburst.

By tracking the motion of these bullets with the VLBA, astronomers were able to link the ejection event to the disappearance of X-ray signals seen in RXTE data.

These signals, called quasi-periodic oscillations (QPOs), vanished two days earlier than the onset of the radio flare that astronomers previously had assumed signaled the ejection.

(Credit: NRAO and NASA's Goddard Space Flight Center).

Kat-7 Astronomers: Closing on Black Hole mystery

Astronomers could soon be a step closer to unravelling the mystery of why galaxies are smaller than astronomers predict.

From January next year, the Karoo Array Telescope-7 (Kat-7) in South Africa will be able to investigate whether black holes are holding back galaxy growth, as well as probing other phenomena such as gravitational waves and cosmic rays.

Kat-7 has been built in the Northern Cape as a test bed for a 3,000km-wide array that will become fully operational in 2024.

Small black holes, five or 10 times the mass of our Sun, and those up to a billion times larger - deemed "supermassive" - had been thought to only consume matter.

But scientists have discovered that they emit jets of matter too, and - given that massive black holes are believed to lie at the heart of galaxies - these jets could explain why galaxies are smaller than predicted.
The period during which these galactic geysers are active varies with the mass of the black hole.

Those small black holes can be active for a brief period every 20 years. However, supermassive black holes can be active for millions of years and then be dormant for a billion.

These jets can stretch out for up to 100,000 light-years. This means to travel from the black hole to the end of the jet would take 100,000 years travelling at light speed.

The jets are visible to scientists at radio wavelengths. By analysing the jets' radio waves, scientists can gauge how much energy has been released. That amount of energy could be key to understanding the alleged holding back of galaxy growth.

ESA: SMOS satellite 'blinded' by radio interference

The European Space Agency (ESA) said on Wednesday that it had launched a behind-the-scenes campaign to shut down illicit radio and TV transmissions interfering with a major climate satellite.

The 315-million-euro (434-million-dollar) Soil Moisture and Ocean Salinity (SMOS) probe "has been bugged by patches of interference from radar, TV and radio transmissions in what should be a protected band," ESA complained.

"Painstaking efforts to reduce these unwanted signals are now paying off," the Paris-based agency said.

SMOS orbits 760 kilometres (470 miles) above Earth, a low-altitude slot enabling it to gauge the impact of climate change on the movement of water across land, air and sea.

Soon after launch last November 2, scientists realised that interference was "effectively blinding" the probe as it passed over parts of southern Europe, Asia, the Middle East and some coastal zones, ESA said in a press release.

The intrusion has two causes.

One is a leakover into a band of the electromagnetic spectrum (1400-1427 MHz in the L-band) which is assigned to space astronomy and Earth exploration satellites by the International Telecommunications Union (ITU).

This source came from overpowerful transmitters in adjacent bands, ESA said.

The other cause is illegal transmissions by TV, radio links and networks such as security systems that are blasting into the precious radio band.

"Also, terrestrial radars appear to cause interference," ESA said.

The agency said it had had to embark upon "the tricky and lengthy process" of having the illegal transmissions shut down and the excessive out-of-band emissions reduced.

Compton Observatory: Detection of Gamma Ray Bursts

Compton Gamma Ray Observatory
Cosmic gamma ray bursts (GRBs) were discovered by accident in the late 1960's by satellites designed to detect gamma rays produced by atomic bomb tests on Earth.

The GRBs appear first as a brilliant flash of gamma rays, that rises and falls in a matter of minutes. These bursts are often followed by afterglows at X-ray, optical and radio wavelengths.

A major leap forward in understanding the source of cosmic GRBs was made when the Burst and Transient Source Experiment (BATSE) was launched aboard the Compton Gamma Ray Observatory in 1991.

BATSE had an all-sky monitor that was capable of detecting a GRB virtually anywhere in the sky. Over a period of 9 years BATSE recorded thousands of GRBs, about 1 per day. Among other things, these results showed that the bursts occurred at random all over the sky.

If the bursts were associated with objects in our Milky Way Galaxy, they would not show such a universal distribution. Rather, they would be concentrated along the plane of our galaxy like most of the matter in the Milky Way.

The BATSE data was so good that it allowed astronomers to also rule out the possibility that the GRBs might be originating in the halo of our galaxy.

The Observatory was named in honor of Dr. Arthur Holly Compton, who won the Nobel prize in physics for work on scattering of high-energy photons by electrons - a process which is central to the gamma-ray detection techniques of all four instruments.

Read the full article on the Chandra X-ray Observatory here ....

Centauris A: Enormous Galaxy found

This composite image compares the radio glow of an enormous galaxy called Centaurus A to a full Moon.

The white dots in the sky are not stars but other sources of radio emissions that are smaller, or more distant than Centaurus A.

The foreground antennas are the Australia Telescope Compact Array , which captured the radio data used to make up the image.

(Image: Ilana Feain, Tim Cornwell & Ron Ekers (CSIRO/ATNF) / R. Morganti (ASTRON) / N. Junkes (MPIfR) / Shaun Amy, CSIRO.)