Posted on by Nancy Atkinson

Nearby Galaxy Has Two Monster Black Holes

Viewed in visible light, Markarian 739 resembles a smiling face. Inside are two supermassive black holes, separated by about 11,000 light-years. The galaxy is 425 million light-years away from Earth. Credit: Sloan Digital Sky Survey

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Why does this galaxy appear to be smiling? The answer might be because it has been holding a secret that astrophysicists have only now just uncovered: there are two — count ‘em – two gigantic black holes inside this nearby galaxy, named Markarian 739 (or NGC 3758), and both are very active. While massive black holes are common, only about one percent of them are considered as active and powerful – called active galactic nuclei (AGN). Binary AGN are rarer still: Markarian 739 is only the second identified within half a billion light-years from Earth.

Markarian 739 is actually a pair of merging galaxies. For decades, astronomers have known that the eastern nucleus of Markarian 739 contains a black hole that is actively accreting matter and generating an exceptional amount of energy. Now, data from the Swift satellite along with the Chandra X-ray Observatory Swift has revealed an AGN in the western half as well. This makes the galaxy one of the nearest and clearest cases of a binary AGN.

The galaxy is 425 million light-years away from Earth.

How did the second AGN remain hidden for so long? “Markarian 739 West shows no evidence of being an AGN in visible, ultraviolet and radio observations,” said Sylvain Veilleux, a professor of astronomy at University of Maryland in College Park , and a coauthor of a new paper published in Astrophysical Journal Letters. “This highlights the critical importance of high-resolution observations at high X-ray energies in locating binary AGN.”

Since 2004, the Burst Alert Telescope (BAT) aboard Swift has been mapping high-energy X-ray sources all around the sky. The survey is sensitive to AGN up to 650 million light-years away and has uncovered dozens of previously unrecognized systems.

Michael Koss, the lead author of this study, from NASA’s Goddard Space Flight Center and UMCP, did follow-up studies of the BAT mapping and he and his colleagues published a paper in 2010 that revealed that about a quarter of the Swift BAT AGN were either interacting or in close pairs, with perhaps 60 percent of them poised to merge in another billion years.

“If two galaxies collide and each possesses a supermassive black hole, there should be times when both black holes switch on as AGN,” said coauthor Richard Mushotzky, professor of astronomy at UMCP. “We weren’t seeing many double AGN, so we turned to Chandra for help.”

Swift’s BAT instrument is scanning one-tenth of the sky at any given moment, its X-ray survey growing more sensitive every year as its exposure increases. Where Swift’s BAT provided a wide-angle view, the X-ray telescope aboard the Chandra X-ray Observatory acted like a zoom lens and resolved details a hundred times smaller.

The distance separating the two black holes is about 11,000 light-years , or about a third of the distance separating the solar system from the center of our own galaxy. The dual AGN of Markarian 739 is the second-closest known, both in terms of distance from one another and distance from Earth. However, another galaxy known as NGC 6240 holds both records.

Source: Swift Telescope webpage

You can follow Universe Today senior editor Nancy Atkinson on Twitter: @Nancy_A. Follow Universe Today for the latest space and astronomy news on Twitter @universetoday and on Facebook.

Posted on by Tammy Plotner

A Chang’e-2 Space…

Chang'e 2 satellite artist realization

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On June 9, Chang’e-2, China’s second Moon orbiter, left our nearest astronomical neighborhood and headed out into the solar system. It had successfully completed its missions by April 1 and, thanks to its longevity, had enough fuel in reserve to continue exploring. According to China’s State Administration of Science,Technology and Industry for National Defence (SASTIND), making the trip into outer space from the Moon’s orbit is the major step from five remaining tasks assigned to the diminutive satellite.

“It’s the first time in the world for a satellite to be set off from the Moon in remote outer space,” said Zhou Jianliang, deputy chief engineer of the Chang’e-2 measure and control system of the Beijing Aerospace Control Center (BACC).

China’s technological developments are leaping ahead. While controlling a mission to the Moon 400,000 km away from the Earth is challenging enough, attempting to command a spacecraft from 1.5 million km presents a huge milestone in measure and control, telecommunications, data transaction and orbit design.

Before flying away, Chang’e-2 finished two additional tasks as of May 23. Its first was to take snapshots of the lunar northern and southern pole and the second was to descend into perilune orbit, about 15 km away from the surface. This time to take high-resolution images of the Sinus Iridum – the proposed landing ground for future Moon missions. The completion of satellite’s tasks has Chinese scientists smiling and hoping things continue well towards the end of next year.

“We are developing outer space measure and control stations in outer space and they will be capable to carry out tasks by the end of the second half next year,” said an SASTIND scientist, who declined to be named. “At that time, the satellite can be used to test the two stations’ functions.”

But the road ahead for Chang’e-2 isn’t going to be an easy one, simply because the satellite wasn’t designed to do what it is now doing. Extended distances mean unexpected problems with communication and control, but the little “Moon Goddess” just may be up to the task.

Original Story Source: China News.

Posted on by Nancy Atkinson

Giant “Surfing” Waves Roll Through Sun’s Atmosphere

Surfer waves -- initiated in the sun, as they are in the water, by a process called a Kelvin-Helmholtz instability -- have been found in the sun's atmosphere. Credit: NASA/SDO/Astrophysical Journal Letters

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Surf’s up on the Sun! Our favorite gnarly spacecraft, the Solar Dynamics Observatory (SDO) has caught conclusive evidence of classic “surfer waves” in the Sun’s atmosphere. But these waves trump ‘Hawaii Five-O’ surfing big time, as they are about the same size as the continental U.S. Spotting these waves will help our understanding of how energy moves through the solar atmosphere, known as the corona and maybe even help solar physicists be able to predict events like Coronal Mass Ejections.

Just like a surfing wave on Earth, the solar counterpart is formed by the same fluid mechanics — in this case it is a phenomenon known as a Kelvin-Helmholtz instability. Since scientists know how these kinds of waves disperse energy in water, they can use this information to better understand the corona. This in turn, may help solve an enduring mystery of why the corona is thousands of times hotter than originally expected.

“One of the biggest questions about the solar corona is the heating mechanism,” says solar physicist Leon Ofman of NASA’s Goddard Space Flight Center, Greenbelt, Md. and Catholic University, Washington. “The corona is a thousand times hotter than the sun’s visible surface, but what heats it up is not well-understood. People have suggested that waves like this might cause turbulence which cause heating, but now we have direct evidence of Kelvin-Helmholtz waves.”

Even though these waves occur frequently in nature here on Earth, no one had seen them on the Sun. But that was before SDO.

Ofman and colleagues spotted these waves in images taken on April 8, 2010 in some of the first images caught on camera by SDO, which launched in Feburary last year and began capturing data on March 24, 2010. Ofman & team have just published a paper in Astrophysical Journal Letters.

Kelvin-Helmholtz instabilities occur when two fluids of different densities or speeds flow by each other. In the case of ocean waves, that’s the dense water and the lighter air. As they flow past each other, slight ripples can be quickly amplified into the giant waves loved by surfers. In the case of the solar atmosphere, which is made of a very hot and electrically charged gas called plasma, the two flows come from an expanse of plasma erupting off the sun’s surface as it passes by plasma that is not erupting. The difference in flow speeds and densities across this boundary sparks the instability that builds into the waves.

On the sun, the two fluids are both plasmas — expanses of super hot, charged gases — which interact. One is erupting from the surface and shooting past a second plasma that is not erupting. The resulting turbulence is a Kelvin-Helmholtz wave form.

The erupting plasma is likely from a Coronal Mass Ejection, such as was seen earlier this week, where the Sun violently propels massive amounts of high-speed plasma particles into space. So, knowing more about the how the corona is heated and what the conditions are just before the KH waves form might give scientists the ability to predict a the next CME, which is a long-standing goal of solar scientists.

But figuring out the exact mechanism for heating the corona will likely keep solar physicists busy for quite some time. However, SDO’s ability to capture images of the entire sun every 12 seconds with such precise detail will certainly provide the data needed.

Source: NASA

You can follow Universe Today senior editor Nancy Atkinson on Twitter: @Nancy_A. Follow Universe Today for the latest space and astronomy news on Twitter @universetoday and on Facebook.

Posted on by Nancy Atkinson

Are YOU the Next Astronomy Photographer of the Year?

'Blazing Bristlecone' by Tom Lowe of the USA, winner of the 2010 years Astronomy Photographer of the Year competition.

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Astrophotography is one thing we can’t get enough of here on Universe Today and some of the best amateur astronomy images can be found at the Astronomy Photographer of the Year competition. Interested in entering? There’s just over a month to go until the Royal Observatory in Greenwich’s annual contest closes. If you have taken some astrophotos this year, why not enter? You’ll need to submit any entries by 13 July, 2011 for a chance of winning what has become a prestigious award for amateur astronomers.

The prizes include a top prize of £1,500 and pride of place in the exhibition of photos which opens at the ROG in September. I was fortunate to be on hand for the award ceremony in 2010, and it was a wonderful event. Each entrant can submit up to five images to the competition and some truly breathtaking photos can already be seen on the official Flickr page for the competition.

There are four main categories you can enter: Earth & Space, Our Solar System, Deep Space and Young Astronomy Photographer of The Year. And this year there are also three special awards – one for newcomers, another for shots that creatively capture people and space, and a third for images that have been taken by robotic/remote telescopes and that have been processed by you.

Photographers can enter online by visiting www.nmm.ac.uk/astrophoto, where full competition rules and some top tips on photographing everything from star trails to deep space objects are also available.

The panel of judges includes Sir Patrick Moore and the ROG’s Public Astronomer Dr. Marek Kukula. The winners will be announced at an awards ceremony on the 8 September, and an exhibition of the winning images will open to the public at the Royal Observatory the following day.

Good luck, and we hope to be posting YOUR winning image here on Universe Today!

You can follow Universe Today senior editor Nancy Atkinson on Twitter: @Nancy_A. Follow Universe Today for the latest space and astronomy news on Twitter @universetoday and on Facebook.

Posted on by Nancy Atkinson

Aquarius Satellite Launches to Observe Earth’s Oceans

A picture-perfect launch on a Delta II rocket from Vandeberg Air Force Base in California sent the newest satellite into orbit. The Aquarius/SAC-D spacecraft lifted off June 10, 2011 at 7:20 a.m. PDT (1420 UTC) to gather global measurements of ocean surface salinity, leading to a better understanding of ocean circulation, climate and Earth’s water cycle. NASA’s Aquarius instrument is part of the SAC-D spacecraft built by CONAE, Argentina’s space agency.

Continue reading “Aquarius Satellite Launches to Observe Earth’s Oceans”

Posted on by Nancy Atkinson

Soyuz Arrives at Space Station

Guess who’s coming for dinner! Three astronauts from three different countries arrived at the International Space Station on Thursday, bringing the compliment of crewmembers on board the orbiting laboratory back to six. Mike Fossum (US), Sergei Volkov (Russian) and Satoshi Furukawa (Japan) were greeted by fellow Expedition 28 members Andrey Borisenko, Ron Garan, and Alexander Samokutyaev after their launch two days ago from the Baikonur Cosmodrome in Kazakhstan. The video includes some stunning views of the Soyuz edging closer to the ISS with the bright limb of Earth in the background, and glittering solar arrays bidding welcome to the crew.

Posted on by Nancy Atkinson

Voyagers Find Giant Jacuzzi-like Bubbles at Edge of Solar System

Artist's interpretation depicting the new view of the heliosphere. The heliosheath is filled with “magnetic bubbles” (shown in the red pattern) that fill out the region ahead of the heliopause. In this new view, the heliopause is not a continuous shield that separates the solar domain from the interstellar medium, but a porous membrane with fingers and indentations. Credit: NASA/Goddard Space Flight Center/CI Lab

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The barrier at the edge of our Solar System may not be the smooth shield that scientists once thought. The venerable Voyager spacecraft have detected a huge, turbulent sea of magnetic bubbles in the heliosheath — the interface between the heliosphere and interstellar space — similar to an actively bubbling Jacuzzi tub. At a briefing today, scientists said the finding is significant as “we now will have to change our view of how the Sun interacts with the Solar System,” said Arik Posner, Voyager program scientist at NASA Headquarters. But it also means that the “force field” that surrounds the entire Solar System may be letting in more harmful cosmic rays and energetic particles than previously thought.

Over 30 years into their mission, the Voyagers are still monitoring their environment and sending back data. In 2007, scientists noticed that Voyager 1 recorded dramatic dips and rises in the amount of electrons it encountered as it traveled through the heliosphere, the barrier that surrounds the entire Solar System and is created by the Sun’s magnetic field. Voyager 2 made similar observations of these charged particles in 2008.

Computer simulation of the magnetic reconnection in the heliosheath, which look like bubbles, or sausages. Credit: NASA/J.F. Drake, M. Swisdak, M. Opher

Using a new computer model to analyze the data, scientists found the Sun’s distant magnetic field is likely made up of bubbles approximately 100 million miles (160 million kilometers) wide — “like long sausages,” said Merav Opher at the briefing, an astronomer at Boston University who is the lead author of a paper published in the Astrophysical Journal.

And the bubbles are moving around, with oscillations of plus or minus 10 to 20 km. “It is very bubbly as far as we can tell,” Jim Drake from the University of Maryland said at the press conference. “The entire thing is bubbly, like where the jets come out from a Jacuzzi.”

Opher said the bubbles, while not visible from Earth, cover a large portion of the sky at about 38 degrees latitude and as the solar winds “bumps” up against the heliopause, the bubbles fill up the entire region next to the heliopause.

Like Earth, our Sun has a magnetic field with a north pole and a south pole. The field lines are stretched outward, and as the sun rotates, the solar wind twists them into a spiral as they are carried outward.
The bubbles are created when magnetic field lines reorganize. The new model suggests the field lines are broken up into self-contained structures disconnected from the solar magnetic field.

These magnetic bubbles should act as electron traps, so the spacecraft would experience higher than normal electron bombardment as they traveled through the bubbles.

But the implications of this new finding, said Opher, is also that the heliosheath is very different from what scientists expected. She prefaced by saying that any earlier ideas about the region was only conjecture since no spacecraft has been there before. “We thought heliopause would be a smooth surface and shield us from intergalactic cosmic rays,” she said. “It is not a shield but more like a membrane that is a sea of bubbles.”

One argument would say the bubbles would seem to be a very porous shield, allowing lots of cosmic rays through the gaps. But another view would be that cosmic rays could get trapped inside the bubbles, making the bubbling froth a very good shield indeed.

However, the scientists are still working on figuring out exactly what these bubbles are. The Voyagers’ instruments, while still working fine, are being tested in this new region of space. “The magnetic instruments on Voyager were designed to measure magnetic fields, but they are right at very edge of what the instruments are capable of sensing,” said Drake. “The magnetic field is very weak. While trying to find out what these magnetic bubbles are, we haven’t reached that moment where we say, ‘yes, that is it.’ We’d like to be able to pin it down much better.”

This video from NASA’s Goddard Spaceflight Center helps to visually explain the new findings:

Sources: NASA press conference, NASA’s Sun/Earth briefing materials, press release, more videos and visuals can be found at this Goddard webpage

You can follow Universe Today senior editor Nancy Atkinson on Twitter: @Nancy_A. Follow Universe Today for the latest space and astronomy news on Twitter @universetoday and on Facebook.

Posted on by Tammy Plotner

Mathematics Explain Dynamics of Superfluid

A 2001 photo from the space shuttle shows a phenomenon called von Karman vortices in clouds downwind from Rashiri Island in the northern Sea of Japan. The vortices are similar to those that form in superfluids. Credit: NASA

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At nearly the coldest temperature possible – mercury (with the aid of liquid helium) – forms a state called superconductivity. At the extreme, electrons flow unencumbered through what is known as a superfluid. But the hows and whys of superfluid behavior defied explanation. Until now…

When taken to within a few degrees of absolute zero on the Kelvin scale (minus 273 Celsius or minus 460 Fahrenheit), liquid helium-4 turns into the remarkable superfluid state. It swirls, it curls, and it’s lack of body has been baffling scientists for nearly a century. Now a team led by a University of Washington physicist, using the most powerful supercomputer available for open science, has cooked up a theoretical picture which explains the real-time behavior of superfluid. Just who is the responsible party here? Try subatomic particles called fermions.

Femions are a much a part of the natural equation as electrons, protons and neutrons… just as superfluids are part of neutron stars. Rotating between one and 1,000 times a second, neutron stars – or pulsars – superfluid surface acts much differently than its counterpart here on Earth. As the speed increases, it forms a series of small vortices which group in a triangular pattern… which in turn forms a braid within the superfluid structure. “When you reach the correct speed, you’ll create one vortex in the middle,” Bulgac said. “And as you increase the speed, you will increase the number of vortices. But it always occurs in steps.”

Can science recreate it? Yes. Laboratory models utilizing a vacuum chamber and a laser beam to create a high-intensity electrical field have managed to chill a small sample, perhaps 1 million atoms, to temperatures near absolute zero. Then a “laser spoon” is employed to stir the superfluid fast enough to create vortices.

“In trying to understand the odd behavior, scientists have attempted to devise descriptive equations, such as ones they might use to describe the swirling action in a cup of coffee as it is stirred.” Bulgac said. “But to describe the action in a superfluid made of fermions, a nearly limitless number of equations is needed. Each describes what happens if just one variable – such as velocity, temperature or density – is changed. Because the variables are linked, if one changes others will change as well.”

One of the major challenges in formulating a mathematical hypothesis is the amount of computing power it would take to work through a problem with a number of variable changes that reached 1 trillion or more. So how did they do it? The team used the JaguarPF computer at Oak Ridge National Laboratory in Tennessee, one of the largest supercomputers in the world, for the equivalent of 70 million hours, which would require almost 8,000 years on a single-core personal computer (JaguarPF has nearly a quarter-million cores). Just try to cool that!

“This tells you the complexity of these calculations and how difficult this is,” Bulgac said. To make matters even more complex, the faster the superfluid is stirred causes it to lose its properties – but not as fast as hypothesized. “The work means that researchers can ‘to some extent’ study the properties of a neutron star using computer simulations.” Bulgac said. .”It also opens new directions of research in cold-atom physics.”

And more homework on our part.

Original Story Source: University of Washington.

Posted on by Tammy Plotner

Rosetta… Stoned Again

Left: Comet Churyumov-Gerasimenko is hidden within this sector of space, a crowded star field in the constellation Scorpius that is towards the center of our galaxy. The image was taken by OSIRIS's wide-angle camera. Middle: The narrow-angle camera allows for a closer look, and shows many background stars. Right: After refined steps of data processing the comet becomes visible. (Credits: ESA 2011 MPS for OSIRIS-Team MPS/UPD/LAM/IAA/RSSD/INTA/UPM/DASP/IDA)

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About 163 million kilometers and three more years separate brave little ESA spacecraft – Rosetta – from comet Churyumov-Gerasimenko. But this seemingly huge distance isn’t stopping determined scientists from the Max Planck Institute for Solar System Research (MPS) in Germany. Their target might be a million times fainter than the faintest star we can see here on Earth with our eyes, but Rosetta has them covered. It has succeeded in imaging the distant comet and it’s right on target.

Using the onboard camera system OSIRIS, Rosetta took its snapshots during testing over the last couple of weeks in preparation for its three year hibernation period. These first images of the tiny, flying space stone only covered a few pixels; “But the pictures already give us a good idea of where we are headed”, says Dr. Holger Sierks from MPS, OSIRIS Lead Investigator. “In addition, they are a remarkable proof of the camera’s performance. We had not expected to be able to create first images from so far away”.

Credits: ESA 2011 MPS for OSIRIS Team MPS/UPD/LAM/IAA/RSSD/INTA/UPM/DASP/IDA and Yuri Beletsky / ESO
Right on? You bet. Here on Earth we’re only able to follow Comet Churyumov-Gerasimenko with the aid of the European Southern Observatory’s Very Large Telescope in Chile, one of the world’s most powerful telescopes with a main mirror diameter of eight meters. By comparison, Rosetta’s OSIRIS camera mirror measures only approximately ten centimeters in diameter. Just like our terrestrial astrophotos, OSIRIS also needed to make a long exposure time as well – to the tune of 13 hours. “All in all, we took 52 images with OSIRIS, each exposed for 15 minutes”, explains Dr. Colin Snodgrass from MPS, responsible for data processing. Once the images were obtained, they were then “stacked” to correct for the comet’s movement against the background stars. This gave researchers their first glimpse of their final destination.

But now it’s going to be a long wait until Rosetta spots the stone again…

Operations manager Andrea Accomazzo gestures happily in the Rosetta control room at ESOC today, just moments after the final command was sent to Rosetta to trigger a 31-month hibernation until January 2014. Credits: ESA
The final command to put Rosetta into sleep mode was sent at 08:00 UT on June 8, 2011. The systems are now shut down for 31 months until the intrepid spacecraft nears its destination in 2014. Its instruments and control systems might be silent for awhile, but its 10 year voyage has been a huge success thus far. “With flybys of asteroids Steins in 2008 and Lutetia in 2010, Rosetta has already delivered excellent scientific results,” says Paolo Ferri, Head of ESOC’s Solar and Planetary Mission Operations Division. Rosetta is simply conserving its solar power until it reaches rendezvous with 67-P/Churyumov-Gerasimenko. But, it’s not entirely silent. The on-board computers and a few heaters are still ticking away – keeping time until its orbit takes it from 660 million km from Sol.

“We sent the command via NASA’s 70 m Deep Space Network station in Canberra, Australia, ensuring the signal was transmitted with enough power to reach Rosetta, which is now 549 million km from Earth,” said ESA’s Spacecraft Operations Manager Andrea Accomazzo. “We’ll monitor via ESA’s 35 m station at New Norcia in Australia for a few days to see if any problems occur, but we expect to receive no radio signal until 2014. Rosetta’s on her own now.”

Is there a handsome prince waiting in Rosetta’s future? Yes, in the form of a timer which will wake the slumbering spacecraft princess. When the moment arrives a signal will be transmitted back to Earth and mission control will then take command. Over a period of weeks Rosetta will “warm up” again in preparation for its landmark arrival at the distant, icy space stone. “Hibernation is a necessary step to reach the final target.” says Ferri. “We are now looking forward to 2014, when Rosetta becomes the first spacecraft to track the life of a comet as it arcs in toward the Sun.”

Rosetta? Rock on!

Original Story Sources: Max Planck Institute for Solar System Research and ESA Space Science.

Posted on by Nancy Atkinson

Zoom into the Epic Images of Endeavour Docked to the ISS

Credit: NASA

Are you enjoying the historic images of space shuttle Endeavour docked to the ISS? Here’s a wonderful new way to experience them. John Williams of Terrazoom and StarryCritters has created an amazing “zoomable” slide show of these images, which allows viewers to quickly zoom into whatever part of the picture you want to see close up. Want to take a good look at Endeavour’s heat tiles or examine a module of the ISS? Just choose a picture and slide the scale (between the plus and minus sign) at the bottom of the application to zoom in.

Thanks to John for sharing his “Zoomify” technology with Universe Today!

See the slideshow on Terrazoom for the option for a full screen version.

Continue reading “Zoom into the Epic Images of Endeavour Docked to the ISS”