Dramatic Moonset — Amazing Sight on Cerro Paranal

Moonset on Cerro Paranal. Credit: ESO

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Need a new desktop image? Usually the Very Large Telescope on Cerro Paranal in Chile provides us with stunning views of the cosmos. This image, however, is a gorgeous view of the observatory itself. As the Moon was setting after a long night of observing, ESO staff member Gordon Gillet welcomed the new day by capturing this stunning image from 14 km away. This image is not a montage or computer-generated (such as the infamous ‘Moon and Sun over the North Pole‘ urban legend)

The ESO website explains:

The Moon appears large because it is seen close to the horizon and our perception is deceived by the proximity of references on the ground. In order to get this spectacular close view, a 500-mm lens was necessary. The very long focal length reduces the depth of field making the objects in focus appear as if they were at the same distance. This effect, combined with the extraordinary quality of this picture, gives the impression that the Moon lies on the VLT platform, just behind the telescopes, even though it is in fact about 30,000 times further away.

Interestingly, Gillet took the image from the road leading to the nearby Cerro Armazones, the peak recently chosen by the ESO Council as the preferred location for the planned 42-meter European Extremely Large Telescope (E-ELT), which should be open for business by 2018.

Source: ESO

Scientist Explains New LOFAR Image of Quasar 3C196

Radio images of the quasar 3C 196 at 4 - 10 m wavelength (30 - 80 MHz frequency). Left: Data from LOFAR stations in the Netherlands only. The resolution is not sufficient to identify any substructure. Right: Blow-up produced with data from the German stations included. The resolution of this image is about ten times better and allows for the first time to distinguish fine details in this wavelength range. The colours are chosen to resemble what the human eye would see if it were sensitive to radiation at a wavelength ten million times larger than visible light. Image: Olaf Wucknitz, Bonn University (Click to enlarge image).

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We received several questions about our article on the new high-resolution LOFAR (LOw Frequency Array) image of quasar 3C196, concerning what was actually visible in this new image. We contacted LOFAR scientist Olaf Wucknitz from the Argelander-Institute for Astronomy at Bonn University in Germany, and he has provided an extensive explanation.

“3C196 is a quasar, the core of which is sitting right in the middle of the radio component,” Wucknitz said. “The core itself is not seen in radio observations but only on optical images. A possible reason for not seeing the core or the jets is that the central engine may not be very active at the moment (or rather it was not very active when the radiation left the object about 7 billion years ago). Alternatively it is possible that the inner parts of this source radiate very inefficiently so that we just do not see them in the radio images.”

In any case, he said, there must have been considerable activity earlier, because extensions of the jets that form radio lobes and hot spots are able to be seen in the image.

“The main lobes seem to be the bright SW component and the more compact NE component. When compared to observations at higher frequencies, these have the flattest spectra, i.e. they dominate at higher frequencies,” Wucknitz continued. “Then there is the other pair of components, the fuzzier E and W components. They are much weaker at higher frequencies.”

“The standard explanation for this would be that the jets from the core are changing its orientation with time (e.g. due to precession caused by a second black hole near the core, but this is very speculative). In this scenario the more extended components are older. Because of their age, the electrons causing the radiation have lost so much energy that we now see more low-frequency (i.e. low energy) radiation. The more compact components would be younger and therefore produce more high-frequency radiation.”

Interestingly, the W and E components show very different “colors” between 30-80 MHz, he said, so there must be some difference in the physical conditions in these two regions.

“Another possible explanation is that the compact components are the main lobes. There the jets interact with the surrounding medium. The matter is deflected and causes an outflow which we see as the other components.”

So basically, Wucknitz said, with the study of the data now available, they cannot draw firm conclusions, and he and his team have not had the opportunity to write a paper on the new image. “At the moment we are concentrating on getting LOFAR to run routinely and try to resist the temptation to do too much science with the first images. I hope that we can provide a real scientific analysis of this and similar images later this year.”

However, he suggested a couple of earlier papers that discuss quasar 3C196.

“Rotationally symmetric structure in two extragalactic radio sources” by Lonsdale, C. J.; Morison, I. describes the model of rotating jets for several obects including 3C196.

And this paper, Kiloparsec scale structure in the hotspots of 3C 196 by Lonsdale, C. J. discuses how previous observations by the MERLIN array revealed the presence of complex structure in each of the two bright hot spots in the quasar.

Wucknitz said he looks forward to delving into this object deeper as more of the LOFAR stations come online. “Once we can calibrate our new data better and produce slightly nicer images, we can hopefully say more and decide for one of the models,” he said.

Thanks to Olaf Wucknitz for providing an explanation of this new LOFAR image. Still have questions? Post them in the comments below.

SOFIA Sees First Light

With a NASA F/A-18 flying safety chase nearby, NASA's Stratospheric Observatory for Infrared Astronomy – or SOFIA – flies a test mission over the Mojave Desert with the sliding door over its 17-ton infrared telescope open. Credit: NASA/ Jim Ross

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Flying SOFIA has opened her eyes! The Stratospheric Observatory for Infrared Astronomy (SOFIA), a joint program by NASA and the German Aerospace Center made its first observations on May 26. The new observatory uses a modified 747 airplane to carry a German-built 2.5 meter (100 inch) reflecting telescope. “With this flight, SOFIA begins a 20-year journey that will enable a wide variety of astronomical science observations not possible from other Earth and space-borne observatories,” said Jon Morse, Astrophysics Division director in the Science Mission Directorate at NASA. “It clearly sets expectations that SOFIA will provide us with “Great Observatory”-class astronomical science.”

Scientists are now processing the first light data, and say that preliminary results show the sharp, “front-line” images that were predicted for SOFIA. They reported the stability and precise pointing of the German-built telescope met or exceeded the expectations of the engineers and astronomers who put it through its paces during the flight.

Infrared image of Jupiter from SOFIA’s First Light flight composed of individual images at wavelengths of 5.4 (blue), 24 (green) and 37 microns (red) made by Cornell University’s FORCAST camera. A recent visual-wavelength picture of approximately the same side of Jupiter is shown for comparison. The white stripe in the infrared image is a region of relatively transparent clouds through which the warm interior of Jupiter can be seen. (Visual image credit: Anthony Wesley)

“The crowning accomplishment of the night came when scientists on board SOFIA recorded images of Jupiter,” said USRA SOFIA senior science advisor Eric Becklin. “The composite image from SOFIA shows heat, trapped since the formation of the planet, pouring out of Jupiter’s interior through holes in its clouds.”

Faint specks of starlight are reflected by the 100-inch (2.5 meter) primary mirror on SOFIA. Credit: NASA/Tom Tschida

Cornell University built the primary instrument on the telescope, the Faint Object infrared Camera for the SOFIA Telescope, also known as FORCAST. FORCAST is unique in that it records energy coming from space at infrared wavelengths between 5 and 40 microns – most of which cannot be seen by ground-based telescopes due to blockage by water vapor in Earth’s atmosphere. SOFIA’s operational altitude, which is above more than 99 percent of that water vapor, allows it to receive 80 percent or more of the infrared light accessible to space observatories, so FORCAST captures in minutes images that would require many hour-long exposures by ground-based observatories

Composite infrared image of the central portion of galaxy M82, from SOFIA’s First Light flight, at wavelengths of 20 (blue), 32 (green) and 37 microns (red). The middle inset image shows the same portion of the galaxy at visual wavelengths. The infrared image views past the stars and dust clouds apparent in the visible-wavelength image into the star-forming heart of the galaxy. The long dimension of the inset boxes is about 5400 light years. (Visual image credit: N. A. Sharp/ NOAO/AURA/NSF)

The first light flight took off from SOFIA’s home base at the Aircraft Operations Facility in Palmdale, Calif., of NASA’s Dryden Flight Research Center. The in-flight personnel consisted of an international crew from NASA, the Universities Space Research Association in Columbia, Md., Cornell University and the German SOFIA Institute (DSI) in Stuttgart. During the six-hour flight, at altitudes up to 35,000 feet, the crew of 10 scientists, astronomers, engineers and technicians gathered telescope performance data at consoles in the aircraft’s main cabin.

More info on SOFIA.

Source: NASA

The Story Behind SOFIA, NASA’s Flying Observatory

The Boeing 747SP used for the SOFIA project is 45 feet shorter than a modern 747, making it lighter and more able to make long transoceanic flights without stopping to refuel. Credit: Lauren Gold/Cornell Chronicle

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From the Cornell University Chronicle, written by Lauren Gold:

The SOFIA project has been in the making for more than 13 years — but the airplane has an even longer history. Originally owned by Pan Am, the 747SP (Special Performance) was named the Clipper Lindbergh and christened by Anne Morrow Lindbergh in 1977 on the 50th anniversary of Lindbergh’s flight across the Atlantic.

The Boeing 747SP differs from a modern 747 in a few ways. Most notably, it’s 45 feet shorter and, thus, lighter — which allowed it to make long transoceanic flights without stopping to refuel. (Modern 747s have much more efficient engines.)

The plane already had two Cornell connections long before astronomy professor and principal investigator Terry Herter and his team installed FORCAST onto the telescope in February.

When Boeing was designing the plane in the 1970s, they hired a young Cornell mechanical engineering graduate to design its horizontal stabilizer (which allows the pilot to raise or lower the nose of the plane in flight). That engineer, Bill Nye ’77, eventually went on to become “Bill Nye the Science Guy” — the Emmy Award-winning science educator and Cornell Frank H.T. Rhodes Class of 1956 Professor from 2001 to 2006.

A decade later in 1989, when the plane was in commercial service, George Gull, Cornell research support specialist and now lead engineer for FORCAST, just happened to notice the “Clipper Lindbergh” insignia on his plane when he flew from Hong Kong to San Francisco after a Cornell Glee Club trip to China.

So while Gull won’t be one of the lucky few on the plane for the May 25 first light flight — he can boast having flown on the plane 21 years before everyone else on the team.

Since NASA bought the Clipper Lindbergh in 1997, SOFIA has undergone more than a few changes. Among many other things, it has a 16-by-23-foot door cut into the port side for the telescope and a bump near the rear of the plane that smoothes out airflow around the fuselage when the telescope door is open.

Currently, a grid of what looks like hundreds of small dots — actually pieces of yarn — cover the surface of the telescope door and the area around it. The yarn is a low-tech but effective way of optimizing aerodynamics — researchers flying alongside SOFIA in a chase plane videotape the yarn’s motion to analyze air flow around the door. The yarn will be removed when the observatory goes into regular operation.

Inside, the plane has a few remnants of its past: several original seats; the spiral staircase to the upper deck; an array of analog instruments in the cockpit. But most of the seats are a hodgepodge of military airplane seats at workstations, facing backward toward the massive, 17-ton telescope and instruments.

The cabin also includes an area for educators and reporters who will take part in flights as part of the mission’s effort to educate and engage the public. And the telescope itself is part of a pressure bulkhead that allows the main cabin to stay pressurized despite the open door behind it.

Despite its novelty, SOFIA follows a long history of airborne astronomy that started with observations made from biplanes in the 1920s and ’30s. Most recently, NASA’s Kuiper Airborne Observatory, a modified Lockheed C-141 with a 1-meter infrared telescope that operated 1974-95, was the vehicle for discoveries including the rings around Uranus, the atmosphere around Pluto and the presence of water vapor in the interstellar medium.

Source: Cornell

WISE Pictures the Tadpole Nebula with a String of Pearls

This image from WISE shows the Tadpole nebula. Image credit: NASA/JPL-Caltech/UCLA

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The Tadpole nebula is looking very stylish in this new infrared image from the WISE spacecraft, NASA’s Wide-field Infrared Survey Explorer. An asteroid appears like a string of pearls — seen as a line of yellow-green dots in the boxes near center — in this stitched together mosaic. The Tadpole is a star-forming region in the Auriga constellation about 12,000 light-years from Earth. As WISE scanned the sky, it happened to catch asteroid 1719 Jens in action, moving across WISE’s field of view. A second asteroid was also observed cruising by, as highlighted in the boxes near the upper left (the larger boxes are blown-up versions of the smaller ones).

More on this image below, but the WISE team received a bit of bad news this week.

WISE principal investigator Ned Wright and his team had proposed a three-month “warm” extension of the mission after the supply of hydrogen that cools the telescope and detectors on board runs out. However, according to an article in Space News, NASA’s 2010 Astrophysics Senior Review Committee recommended that the mission not be extended, and end as originally planned in October of this year.

While WISE is expected to produce significant results, the committee said there was not adequate scientific justification to continue the mission.

The proposed additional three months, known as Warm WISE – where the spacecraft would observe in two of the four infrared wavelengths it has available when WISE is cooled –would have added $6.5 million to the program’s $320 million price tag.

Currently, WISE produces approximately 7,500 images a day.

And this latest image is a “gem.”

It consists of twenty-five frames, taken at all four of the wavelengths and were combined into one image: infrared light of 3.4 microns is color-coded blue: 4.6-micron light is cyan; 12-micron-light is green; and 22-micron light is red.

But wait, there’s more! Also visible in the image are two satellites orbiting above WISE (highlighted in the ovals). They streak through the image, appearing as faint green trails. The apparent motion of asteroids is slower than satellites because asteroids are much more distant, and thus appear as dots that move from one WISE frame to the next, rather than streaks in a single frame.

This Tadpole region is chock full of stars as young as only a million years old — infants in stellar terms — and masses over 10 times that of our sun. It is called the Tadpole nebula because the masses of hot, young stars are blasting out ultraviolet radiation that has etched the gas into two tadpole-shaped pillars, called Sim 129 and Sim 130. These “tadpoles” appear as the yellow squiggles near the center of the frame. The knotted regions at their heads are likely to contain new young stars. WISE’s infrared vision is helping to ferret out hidden stars such as these.

WISE is an all-sky survey, snapping pictures of the whole sky, including everything from asteroids to stars to powerful, distant galaxies.

Sources: JPL, Space News

Young Stars Blast a Hole in Space

The black spot in the green-tinged cloud near the top of the image is a hole blown through NGC 1999 by the jets and winds of gas from the young stellar objects in this region of space. Credits: ESA/HOPS Consortium

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There is a black patch of space in NGC 1999, and for years astronomers have thought it was just a dense cloud of gas and dust, blocking light from passing through. But the Herschel infrared space telescope – which has the ability to peer into these dense clouds — has made an unexpected discovery. This black patch is actually a hole that has been blown in the side of the nebula by the jets and winds of gas from the young stellar objects in this region of space. “No-one has ever seen a hole like this,” said Tom Megeath, of the University of Toledo in the USA. “It’s as surprising as knowing you have worms tunneling under your lawn, but finding one morning that they have created a huge, yawning pit.”

Any previous descriptions of NCG 1999 said that the ominous dark cloud in the center was actually a condensation of cold molecular gas and dust so thick and dense that it blocks light. And astronomers had no reason to believe otherwise, until Herschel’s powerful infrared eyes took a look from space.

A Hubble image of NCG 1999 showing the dark patch. Credit: Hubble Heritage Team (STScI) and NASA

When Herschel looked in the direction of this nebula to study nearby young stars, the cloud continued to look black. But, that should not be the case. Herschel’s infrared eyes are designed to see into such clouds. Either the cloud was immensely dense or something was wrong.

Investigating further using ground-based telescopes, astronomers found the same story however they looked: this patch looks black not because it is a dense pocket of gas but because it is truly empty. Something has blown a hole right through the cloud.

Stars are born in dense clouds of dust and gas. Although jets and winds of gas have been seen coming from young stars in the past, it has always been a mystery exactly how a star uses these to blow away its surroundings and emerge from its birth cloud. With Herschel, this may be the first time we can see this process.

The astronomers think that the hole must have been opened when the narrow jets of gas from some of the young stars in the region punctured the sheet of dust and gas that forms NGC 1999. The powerful radiation from a nearby mature star may also have helped to clear the hole. Whatever the precise chain of events, it could be an important glimpse into the way newborn stars disperse their birth clouds.

Source: ESA

Herschel Spots Previously Unseen Stars in Rosette Nebula

Infrared image of the Rosette molecular cloud by the Herschel space observatory. Credits: ESA/PACS & SPIRE Consortium/HOBYS Key Programme Consortia

Wow, what a gorgeous new image from the Herschel telescope – and what makes this especially stunning is that we’ve never seen these stars before! And these stars in the Rosette Nebula are huge, as each one is up to ten times the mass of our Sun. “High-mass star-forming regions are rare and further away than low-mass ones,” said Frédérique Motte, from the Laboratoire AIM Paris-Saclay, France. “So astronomers have had to wait for a space telescope like Herschel to reveal them.”
Continue reading “Herschel Spots Previously Unseen Stars in Rosette Nebula”

Mystery Object Found Orbiting Brown Dwarf

This Hubble Space Telescope image of young brown dwarf 2M J044144 show it has a companion object at the 8 o'clock position that is estimated to be 5-10 times the mass of Jupiter.Credit: NASA, ESA, and K. Todorov and K. Luhman (Penn State University)

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Big planet or companion brown dwarf? Using the Hubble Space Telescope and the Gemini Observatory, astronomers have discovered an unusual object orbiting a brown dwarf, and its discovery could fuel additional debate about what exactly constitutes a planet. The object circles a nearby brown dwarf in the Taurus star-forming region with an orbit approximately 3.6 billion kilometers (2.25 billion miles) out, about the same as Saturn from our sun. The astronomers say it is the right size for a planet, but they believe the object formed in less than 1 million years — the approximate age of the brown dwarf — and much faster than the predicted time it takes to build planets according to conventional theories.

Kamen Todorov of Penn State University and his team conducted a survey of 32 young brown dwarfs in the Taurus region.

The object orbits the brown dwarf 2M J044144 and is about 5-10 times the mass of Jupiter. Brown dwarfs are objects that typically are tens of times the mass of Jupiter and are too small to sustain nuclear fusion to shine as stars do.

Artist's conception of the binary system 2M J044144. Science Credit: NASA, ESA, and K. Todorov and K. Luman (Penn State University) Artwork Credit: Gemini Observatory, courtesy of L. Cook

While there has been a lot of discussion in the context of the Pluto debate over how small an object can be and still be called a planet, this new observation addresses the question at the other end of the size spectrum: How small can an object be and still be a brown dwarf rather than a planet? This new companion is within the range of masses observed for planets around stars, but again, the astronomers aren’t sure if it is a planet or a companion brown dwarf star.

The answer is strongly connected to the mechanism by which the companion most likely formed.

The Hubble new release offers these three possible scenarios for how the object may have formed:

Dust in a circumstellar disk slowly agglomerates to form a rocky planet 10 times larger than Earth, which then accumulates a large gaseous envelope; a lump of gas in the disk quickly collapses to form an object the size of a gas giant planet; or, rather than forming in a disk, a companion forms directly from the collapse of the vast cloud of gas and dust in the same manner as a star (or brown dwarf).

If the last scenario is correct, then this discovery demonstrates that planetary-mass bodies can be made through the same mechanism that builds stars. This is the likely solution because the companion is too young to have formed by the first scenario, which is very slow. The second mechanism occurs rapidly, but the disk around the central brown dwarf probably did not contain enough material to make an object with a mass of 5-10 Jupiter masses.

“The most interesting implication of this result is that it shows that the process that makes binary stars extends all the way down to planetary masses. So it appears that nature is able to make planetary-mass companions through two very different mechanisms,” said team member Kevin Luhman of the Center for Exoplanets and Habitable Worlds at Penn State University.

If the mystery companion formed through cloud collapse and fragmentation, as stellar binary systems do, then it is not a planet by definition because planets build up inside disks.

The mass of the companion is estimated by comparing its brightness to the luminosities predicted by theoretical evolutionary models for objects at various masses for an age of 1 million years.

Further supporting evidence comes from the presence of a very nearby binary system that contains a small red star and a brown dwarf. Luhman thinks that all four objects may have formed in the same cloud collapse, making this in actuality a quadruple system.

“The configuration closely resembles quadruple star systems, suggesting that all of its components formed like stars,” he said.

The team’s research is being published in an upcoming issue of The Astrophysical Journal.

The team’s paper: Discovery of a Planetary-Mass Companion to a Brown Dwarf in Taurus

Source: HubbleSite

Astronomers Find 90% More Universe!

The GOODS South Field. ESO/M. Hayes

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Astronomers have long known that many surveys of distant galaxies miss 90% of their targets, but they didn’t know why. Now, astronomers have determined that a large fraction of galaxies whose light took 10 billion years to reach us have gone undiscovered. This was found with an extremely deep survey using two of the four giant 8.2-meter telescopes that make up ESO’s Very Large Telescope (VLT) and a unique custom-built filter. The survey also helped uncover some of the faintest galaxies ever found at this early stage of the Universe.

Astronomers frequently use the strong, characteristic “fingerprint” of light emitted by hydrogen known as the Lyman-alpha line, to probe the amount of stars formed in the very distant Universe Yet there have long been suspicions that many distant galaxies go unnoticed in these surveys. A new VLT survey demonstrates for the first time that this is exactly what is happening. Most of the Lyman-alpha light is trapped within the galaxy that emits it, and 90% of galaxies do not show up in Lyman-alpha surveys.

“Astronomers always knew they were missing some fraction of the galaxies in Lyman-alpha surveys,” explains Matthew Hayes, the lead author of the paper, published this week in Nature, “but for the first time we now have a measurement. The number of missed galaxies is substantial.”

To figure out how much of the total luminosity was missed, Hayes and his team used the FORS camera at the VLT and a custom-built narrowband filter to measure this Lyman-alpha light, following the methodology of standard Lyman-alpha surveys. Then, using the new HAWK-I camera, attached to another VLT Unit Telescope, they surveyed the same area of space for light emitted at a different wavelength, also by glowing hydrogen, and known as the H-alpha line. They specifically looked at galaxies whose light has been traveling for 10 billion years (redshift 2.2), in a well-studied area of the sky, known as the GOODS-South field.

“This is the first time we have observed a patch of the sky so deeply in light coming from hydrogen at these two very specific wavelengths, and this proved crucial,” said team member Goran Ostlin. The survey was extremely deep, and uncovered some of the faintest galaxies known at this early epoch in the life of the Universe. The astronomers could thereby conclude that traditional surveys done using Lyman-alpha only see a tiny part of the total light that is produced, since most of the Lyman-alpha photons are destroyed by interaction with the interstellar clouds of gas and dust. This effect is dramatically more significant for Lyman-alpha than for H-alpha light. As a result, many galaxies, a proportion as high as 90%, go unseen by these surveys. “If there are ten galaxies seen, there could be a hundred there,” Hayes said.

Different observational methods, targeting the light emitted at different wavelengths, will always lead to a view of the Universe that is only partially complete. The results of this survey issue a stark warning for cosmologists, as the strong Lyman-alpha signature becomes increasingly relied upon in examining the very first galaxies to form in the history of the Universe. “Now that we know how much light we’ve been missing, we can start to create far more accurate representations of the cosmos, understanding better how quickly stars have formed at different times in the life of the Universe,” said co-author Miguel Mas-Hesse.

The breakthrough was made possible thanks to the unique camera used. HAWK-I, which saw first light in 2007, is a state-of-the-art instrument. “There are only a few other cameras with a wider field of view than HAWK-I, and they are on telescopes less than half the size of the VLT. So only VLT/HAWK-I, really, is capable of efficiently finding galaxies this faint at these distances,” said team member Daniel Schaerer.

Read the team’s paper.

Source: ESO

New Images Unlock Secrets of Jupiter’s Red Spot

New thermal images from powerful ground-based telescopes show swirls of warmer air and cooler regions never seen before within Jupiter's Great Red Spot. Image credit: NASA/JPL/ESO and NASA/ESA/GSFC

It’s difficult enough to track the weather on Earth, but with new thermal images of Jupiter’s Great Red Spot, scientists now have the first detailed interior weather map of a giant storm system on another planet. “This is our first detailed look inside the biggest storm of the solar system,” said Glenn Orton, a senior research scientist at NASA’s Jet Propulsion Laboratory. “We once thought the Great Red Spot was a plain old oval without much structure, but these new results show that it is, in fact, extremely complicated.”
Continue reading “New Images Unlock Secrets of Jupiter’s Red Spot”