A radio dish at Owens Valley Observatory in Owens Valley California. Credit and copyright: Credit and copyright: Harun Mehmedinovic and Gavin Heffernan.
Radio dishes always evoke wonder, as these giants search for invisible (to our eyes, anyway) radio signals from objects like distant quasars, pulsars, masers and more, including potential signals from extraterrestrials. This new timelapse from Harun Mehmedinovic and Gavin Heffernan of Sunchaser Pictures was shot at several different radio astronomy facilities — the Very Large Array (VLA) Observatory in New Mexico, Owens Valley Observatory in Owens Valley California, and Green Bank Observatory in West Virginia. All three of these facilities have been or are still being partly used by the SETI (Search for the Extraterrestrial Intelligence) program.
Watch the dishes dance in their search across the Universe!
The huge meteorite streaking across the sky above Very Large Array (2:40) is from the Aquarids meteor shower. The large radio telescope at Green Bank is where scientists first attempted to “listen” to presence of extraterrestrials in the galaxy. The Very Large Array was featured in the movie CONTACT (1997) while Owens Observatory was featured in THE ARRIVAL (1996).
This video was created for SkyGlowProject.com, a crowdfunded educational project that explores the effects and dangers of urban light pollution in contrast with some of the most incredible Dark Sky Preserves in North America.
The music is by Tom Boddy, and titled “Thoughtful Reflections.”
Thanks to Gavin Heffernan for sharing this video.
Screenshot from the DishDance timelapse. Credit and copyright: Harun Mehmedinovic and Gavin Heffernan.
"Color" radio image of galactic cluster Abell 2256. Credit: Owen et al., NRAO/AUI/NSF.
Even though it’s said that the average human eye can discern from seven to ten million different values and hues of colors, in reality our eyes are sensitive to only a very small section of the entire electromagnetic spectrum, corresponding to wavelengths in the range of 400 to 700 nanometers. Above and below those ranges lie enormously diverse segments of the EM spectrum, from minuscule yet powerful gamma rays to incredibly long, low-frequency radio waves.
Astronomers observe the Universe in all wavelengths because many objects and phenomena can only be detected in EM ranges other than visible light (which itself can easily be blocked by clouds of dense gas and dust.) But if we could see in radio waves the same way we do in visible light waves – that is with longer wavelengths being perceived as “red” and shorter wavelengths seen as “violet,” with all the blues, greens, and yellows in between – our world would look quite different… especially the night sky, which would be filled with fantastic shapes like those seen above!
View of the VLA in New Mexico. Image courtesy of NRAO/AUI.
Created from observations made at the Very Large Array in New Mexico, the image above shows a cluster of over 500 colliding galaxies located 800 million light-years away called Abell 2256. An intriguing target of study across the entire electromagnetic spectrum, here Abell 2256 (A2256 for short) has had its radio emissions mapped to the corresponding colors our eyes can see.
Within an area about the same width as the full Moon a space battle between magical cosmic creatures seems to be taking place! (In reality A2256 spans about 4 million light-years.)
See a visible-light image of A2256 by amateur astronomer Rick Johnson here.
The VLA radio observations will help researchers determine what’s happening within A2256, where multiple groups of galaxy clusters are interacting.
“The image reveals details of the interactions between the two merging clusters and suggests that previously unexpected physical processes are at work in such encounters,” said Frazer Owen of the National Radio Astronomy Observatory (NRAO).
Radio image of the night sky. (Credit: Max Planck Institute for Radio Astronomy, generated by Glyn Haslam.)
A composite image in X-ray and radio showing a likely candidate for a jet emanating from the supermassive black hole at the center of the Milky Way. X-ray: NASA/CXC/UCLA/Z.Li et al; Radio: NRAO/VLA
Jets of high energy particles emanating from a black hole have been detected plenty of times before, but in other galaxies, that is — not from the supermassive black hole at the center of the Milky Way, known as Sagittarius A* (Sgr A*). Previous studies and other evidence suggested that perhaps there were jets – or ghosts of past jets – but many findings and studies often contradicted each other, and none were considered definitive.
Now, astronomers using Chandra X-ray Observatory and the Very Large Array (VLA) radio telescope have found strong evidence Sgr A* is producing a jet of high-energy particles.
“For decades astronomers have looked for a jet associated with the Milky Way’s black hole. Our new observations make the strongest case yet for such a jet,” said Zhiyuan Li of Nanjing University in China, lead author of a study in The Astrophysical Journal.
The supermassive black hole at the center of the Milky Way is about four million times more massive than our Sun and lies about 26,000 light-years from Earth.
While the common notion is that black holes inhale and ingest everything that comes their way, that’s not always true. Sometimes they reject small portions of incoming mass, pushing it away in the form of a powerful jet, and many times a pair of jets. These jets also feed the surroundings, releasing both mass and energy and likely play important roles in regulating the rate of formation of new stars.
Sgr A* is presently known to be consuming very little material, and so the jet is weak, making it difficult to detect. Astronomers don’t see another jet “shooting” in the opposite direction but that may be because of gas or dust blocking the line of sight from Earth or a lack of material to fuel the jet. Or there may be just a single jet.
“We were very eager to find a jet from Sgr A* because it tells us the direction of the black hole’s spin axis. This gives us important clues about the growth history of the black hole,” said Mark Morris of the University of California at Los Angeles, a co-author of the study.
The study shows the spin axis of Sgr A* is pointing in one direction, parallel to the rotation axis of the Milky Way, which indicates to astronomers that gas and dust have migrated steadily into Sgr A* over the past 10 billion years. If the Milky Way had collided with large galaxies in the recent past and their central black holes had merged with Sgr A*, the jet could point in any direction.
The jet appears to be running into gas near Sgr A*, producing X-rays detected by Chandra and radio emission observed by the VLA. The two key pieces of evidence for the jet are a straight line of X-ray emitting gas that points toward Sgr A* and a shock front — similar to a sonic boom — seen in radio data, where the jet appears to be striking the gas. Additionally, the energy signature, or spectrum, in X-rays of Sgr A* resembles that of jets coming from supermassive black holes in other galaxies.
The Chandra observations in this study were taken between September 1999 and March 2011, with a total exposure of about 17 days.
The Very Large Array, one of the world's premier astronomical radio observatories, consists of 27 radio antennas in a Y-shaped configuration 50 miles west of Socorro, New Mexico. Each antenna is 82 feet (25 m) in diameter. The data from the antennas is combined electronically to give the resolution of an antenna 22 miles (36 km) across. Image courtesy of NRAO/AUI and NRAO
While some of you will no doubt be heading to the theaters to see the new release of “Gravity,” for those that want to stay in for the weekend, here’s the perfect short film. The National Radio Astronomy Observatory (NRAO) has released a new 24-minute film about the recently renovated Karl G. Jansky Very Large Array (VLA) radio telescope. The film is narrated by Academy Award-winning actress Jodie Foster, star of the 1997 Warner Brothers film, “Contact,” which was filmed in part at the VLA.
“In ‘Contact,’ I played the role of an astronomer using the VLA,” Foster said. “In narrating this new film for the VLA Visitor Center, I have the privilege of introducing tomorrow’s scientists, technicians, and engineers to the amazing complexities of this great telescope, and to the wonders of the universe that it reveals.”
Titled “Beyond the Visible,” the film tells the behind-the-scenes story of the operation and scientific achievements of the VLA, which has been at the forefront of astrophysical research since its dedication in 1980. Spectacular ground and aerial footage of the iconic radio telescope is augmented by first-person interviews with staffers who keep the telescope working and scientists who use it to discover exciting new facts about the universe. The film also depicts many of the technical tasks needed to keep the array functioning at the forefront of science.
“Since the last film for the Visitor Center was produced in 2002, we’ve completed a massive technological upgrade that turned the VLA into a completely new and vastly more powerful tool for cutting-edge science,” said Dale Frail, NRAO’s Director for New Mexico Operations. “It was time to update the story we tell our visitors,” he added.
The film replaces an earlier video that ran at the VLA Visitor Center auditorium, which is visited by some 20,000 people annually. You can’t currently go to the Visitor Center to see the new film at the moment, however, because of the US federal government shutdown. So, watch it here. Hopefully the shutdown will be resolved soon so that people can resume their visits to the VLA.
Combined Hubble (optical) and VLA (radio) images show enormous radio jets shooting out from the galaxy Hercules A
Combined Hubble (optical) and VLA (radio) images show enormous radio jets shooting out from the galaxy Hercules A
Talk about pouring your heart out! Astronomers using Hubble’s Wide Field Camera 3 and the recently-upgraded Karl G. Jansky Very Large Array (VLA) radio telescope in New Mexico have identified gigantic jets of plasma, subatomic particles and magnetic fields blasting out of the center of Hercules A, a massive galaxy 2 billion light-years away.
The image above is a combination of optical images from Hubble and radio data gathered by the multi-dish VLA. If our eyes could see in the high-energy spectrum of radio, this is what Hercules A — the otherwise ordinary-looking elliptical galaxy in the center — would really look like.
(Of course, if we could see in radio our entire sky would be a very optically busy place!)
Also known as 3C 348, Hercules A is incredibly massive — nearly 1,000 times the mass of our Milky Way galaxy with a similarly scaled-up version of a supermassive black hole at its center. Due to its powerful gravity and intense magnetic field Hercules A’s monster black hole is firing superheated material far out into space from its rotational poles. Although invisible in optical light, these jets are bright in radio wavelengths and are thus revealed through VLA observations.
Traveling close to the speed of light, the jets stretch for nearly 1.5 million light-years from both sides of the galaxy. Ring-shaped structures within them suggest that occasional strong outbursts of material have occurred in the past.
Announced on November 29, these findings illustrate the combined imaging power of two of astronomy’s most valuable and cutting-edge tools: Hubble and the newly-updated VLA. The video below shows how it was all done… check it out.
The innermost antennae along the north arm of the Very Large Array, superimposed upon a false-color representation of a radio (red) and optical (blue) image of the radio galaxy 3C31. Image courtesy of NRAO/AUI
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The iconic Very Large Array is almost as much pop culture as science instrument. It’s been part of movie plots, on album covers, in comic books and video games. But now, the VLA is being transformed from its original 1970s-vintage technology with state-of-the-art equipment. The National Radio Astronomy Observatory says that the upgrades will increase the VLA’s technical capabilities by factors of as much as 8,000 and greatly increasing the array’s scientific impact.
And so to befit the VLA’s new capabilities, NRAO has decided the array should have a new name. And they are looking for some help from the public.
The Very Large Array CREDIT: NRAO/AUI/NSF
There is a special website, namethearray.org, where you can submit a name suggestion. You may enter a free-form name, or a word or phrase to come as a prefix before “Very Large Array,” or both.
Entries will be accepted until 23:59 EST on December 1, 2011, and the new name will be announced at NRAO’s Town Hall at the American Astronomical Society’s meeting in Austin, Texas, on Tuesday, January 10, 2012.
“The VLA Expansion Project, begun in 2000, has increased the VLA’s technical capabilities by factors of as much as 8,000, and the new system allows scientists to do things they never could do before,” said Fred K.Y. Lo, Director of the National Radio Astronomy Observatory. “After more than three decades on the frontiers of science, the VLA now is poised for a new era as one of the world’s premier tools for meeting the challenges of 21st-Century astrophysics.”
IRAS 13481-6124 (upper left is about twenty times the mass of our sun and five times its radius. It is surrounded by its pre-natal cocoon. Image credit: NASA/JPL-Caltech/ESO/Univ. of Michigan
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How do massive stars form? This has been one of the more hotly debated questions in astronomy. Do big stars form by accretion like low-mass stars or do they form through the merging of low mass protostars? Since massive stars tend to be quite far away and usually are surrounded by a shroud of dust, they are difficult to observe, said Stefan Kraus from the University of Michigan. But Kraus and his team have obtained the first image of a dusty disc closely encircling a massive baby star, providing direct evidence that, big or small, all stars form the same way.
“Our observations show a disc surrounding an embryonic young, massive star, which is now fully formed,” said Kraus. “It’s the first time something like this has been observed, and the disk very much resembles what we see around young stars that are much smaller, except everything is scaled up and more massive.”
Not only that, but Kraus and his team found hints at a potential planet-forming region around the nascent star.
Using ESO’s Very Large Telescope Interferometer Kraus and his team focused on IRAS 13481-6124, a star located about 10,000 light-years away in the constellation Centaurus, and about 20 times more massive than our sun. “We were able to get a very sharp view into the innermost regions around this star by combining the light of separate telescopes,” Kraus said, “basically mimicking the resolving power of a telescope with an incredible 85-meter (280-foot) mirror.”
Kraus added that the resulting resolution is about 2.4 milliarcseconds, which is equivalent to picking out the head of a screw on the International Space Station from Earth, or more than ten times the resolution possible with current visible-light telescopes in space.
They also made complementary observations with the 3.58-meter New Technology Telescope at La Silla. The team chose this region by looking at archived images from the Spitzer Space Telescope as well as from observations done with the APEX 12-meter submillimeter telescope, where they discovered the presence of a jet.
“Such jets are commonly observed around young low-mass stars and generally indicate the presence of a disc,” says Kraus.
Astronomers have obtained the first clear look at a dusty disk closely encircling a massive baby star, providing direct evidence that massive stars do form in the same way as their smaller brethren -- and closing an enduring debate. This artist's concept shows what such a massive disk might look like. Image credit: ESO/L. Calçada
From their observations, the team believes the system is about 60,000 years old, and that the star has reached its final mass. Because of the intense light of the star — 30,000 times more luminous than our Sun — the disc will soon start to evaporate. The disc extends to about 130 times the Earth–Sun distance — or 130 astronomical units (AU) — and has a mass similar to that of the star, roughly twenty times the Sun. In addition, the inner parts of the disc are shown to be devoid of dust, which could mean that planets are forming around the star.
“In the future, we might be able to see gaps in this and other dust disks created by orbiting planets, although it is unlikely that such bodies could survive for long,” Kraus said. “A planet around such a massive star would be destroyed by the strong stellar winds and intense radiation as soon as the protective disk material is gone, which leaves little chance for the development of solar systems like our own.”
Kraus looks forward to observations with the Atacama Large Millimeter/submillimeter Array (ALMA), currently under construction in Chile, which may be able to resolve the disks to an even sharper resolution.
Previously, Spitzer detected dusty disks of planetary debris around more mature massive stars, which supports the idea that planets may form even in these extreme environments. (Read about that research here.) .
