ESO Image: Lupus 4 - Cosmic Spider Swallows Starlight

A dark, spider-shaped cloud of cosmic gas blocks out light from stars in a new image taken by a telescope in the Southern Hemisphere.

The amazing photo, taken by a telescope at the European Southern Observatory's La Silla Observatory in Chile, is filled with stars glowing brightly in a variety of colours.

Red, blue, yellow and orange stars frame the gas blob called Lupus 4, which blots out light from other, more distant stars in the center of the image. Fly through the image in a new video of the Lupus 4 space cloud from ESO.

Eventually, Lupus 4, which is located about 400 light-years from Earth, could give birth to its own stars.

A dark cloud of gas called Lupus 4 blocks out more-distant stars. Photo released Sept. 3, 2014.

Credit: ESO

"How many stars might eventually start to shine within Lupus 4? It is hard to say, as mass estimates for Lupus 4 vary," ESO representatives said in a statement today (Sept. 3).

"Two studies agree on a figure of around 250 times the mass of the sun, though another, using a different method, arrives at a figure of around 1,600 solar masses."

"Either way, the cloud contains ample material to give rise to plenty of bright new stars."

"Rather as earthly clouds make way for sunshine, so, too, shall this cosmic dark cloud eventually dissipate and give way to brilliant starlight."

Another gas cloud in the same area, called Lupus 3, already hosts about 40 young stars that formed over the course of the last 3 million years, ESO said.

The spidery cloud is part of a loose star cluster named the Scorpius-Centaurus OB association, which is a young, widely dispersed star grouping, according to ESO.

The stars in the cluster also likely come from the same huge cloud of cosmic material, representatives from the astronomy organization added.

Hubble Image: Spiral galaxies engaged in a cosmic tug-of-war

Credit: ESA/Hubble & NASA, Acknowledgement: Luca Limatola

From objects as small as Newton's apple to those as large as a galaxy, no physical body is free from the stern bonds of gravity, as evidenced in this stunning picture captured by the Wide Field Camera 3 and Advanced Camera for Surveys onboard the NASA/ESA Hubble Space Telescope.

Here we see two spiral galaxies engaged in a cosmic tug-of-war but in this contest, there will be no winner.

The structures of both objects are slowly distorted to resemble new forms, and in some cases, merge together to form new, super galaxies.

This particular fate is similar to that of the Milky Way Galaxy, when it will ultimately merge with our closest galactic partner, the Andromeda Galaxy.

There is no need to panic however, as this process takes several hundreds of millions of years.

Not all interacting galaxies result in mergers though. The merger is dependent on the mass of each galaxy, as well as the relative velocities of each body.

It is quite possible that the event pictured here, romantically named 2MASX J06094582-2140234, will avoid a merger event altogether, and will merely distort the arms of each spiral without colliding—the cosmic equivalent of a hair ruffling!

These galactic interactions also trigger new regions of star formation in the galaxies involved, causing them to be extremely luminous in the infrared part of the spectrum.

For this reason, these types of galaxies are referred to as Luminous Infrared Galaxies (LIRGs).

This image was taken as part of as part of a Hubble survey of the central regions of LIRGs in the local Universe, which also used the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) instrument.

Merging galaxies illuminate the cosmic food chain

The Umbrella Galaxy (NGC 4651) takes its name from a mysterious feature seen on the left here, that is now found to be debris from a tiny galaxy, only a 50th its size, shredded apart by gravity. 

The image is a combination of data from the 0.5-meter BlackBird Remote Observatory Telescope and Suprime-Cam on the 8-meter Subaru Telescope. 

The inset shows a small cluster of stars embedded in the stream, which marks the center of the disrupted galaxy. 

Credit: R. JAY GABANY

Scientists studying a 'twin' of the Milky Way have used the W. M. Keck Observatory and Subaru Observatory to accurately model how it is swallowing another, smaller galaxy.

Their findings have opened the way to a better understanding of how structure forms in the universe and are being published in the Monthly Notices of the Royal Astronomical Society this week.

The work, led by Caroline Foster of the Australian Astronomical Observatory, has used the Umbrella Galaxy (NGC 4651) to reveal insights in galactic behaviour.

The Umbrella lies 62 million light-years away, in the northern constellation of Coma Berenices. Its faint parasol is composed of a stellar stream, thought to be the remnants of a smaller galaxy being pulled apart by the large galaxy's intense gravitational field. The Umbrella will eventually absorb this small galaxy completely.

The merging of small galaxies into larger ones is common throughout the universe, but because the shredded galaxies are so faint it has been hard to extract details in three-dimensions about how such mergers proceed.

Using the most powerful optical facilities in the world, the twin, 10-meter Keck Observatory and the 8-meter Subaru Observatory, near the summit of Mauna Kea, Foster and her collaborators have determined enough about the character of the merger to provide a detailed model of how and when it occurred.

In this three-dimensional, rotating computer model of the Umbrella Galaxy (NGC 4651), the disk of the main galaxy is shown by blue circles. 

The path of the dwarf galaxy through space is shown by a green curve. 

The white dots show stars that once belonged to the dwarf galaxy but have now been ripped off by tidal forces into a long stream of stars. 

Credit: N. SINGH/UCSC

After taking panoramic images of the Umbrella with Suprime-Cam on Subaru, the scientists used the DEIMOS instrument, installed on the Keck II telescope, to map out the motions of the stream and hence determine how the galaxy is being shredded.

The stars in the stream are incredibly faint, so it was necessary to use a proxy technique to measure the speeds of brighter tracer objects moving along with the stream stars.

These bright tracers include globular star clusters, planetary nebulae (dying stars that glow like neon lights), and patches of glowing hydrogen gas.

"This is important because our whole concept about what galaxies are and how they grow has not been fully verified," said co-author Aaron Romanowsky, an astronomer at both San José State University and University of California Observatories.

"We think they are constantly consuming smaller galaxies as part of a cosmic food chain, all pulled together by a mysterious form of invisible 'dark matter'.

When a galaxy is torn apart, we sometimes get a glimpse of the hidden vista because the stripping process lights it up. That's what occurred here."

"Through new techniques we have been able to measure the movements of the stars in the very distant, very faint, stellar stream in the Umbrella," Foster said.

"This allows us, for the first time, to reconstruct the history of the system."

"Being able to study streams this far away means that we can reconstruct the assembly histories of many more galaxies," Romanowsky said.

"In turn that means we can get a handle on how often these 'minor mergers,' thought to be an important way that galaxies grow, actually occur.

We can also map out the orbits of the stellar streams to test the pull of gravity for exotic effects, much like the Moon going around the Earth but without having to wait 300 million years for the orbit to complete."

The present work is a follow-up to a 2010 study, led by Dr. David Martínez-Delgado (University of Heidelberg), which used small robotic telescopes to image eight isolated spiral galaxies, and found the signs of mergers, shells, clouds and arcs of tidal debris, in six of them.

The W. M. Keck Observatory operates the largest, most scientifically productive telescopes on Earth.

The two, 10-meter optical/infrared telescopes on the summit of Mauna Kea on the Island of Hawaii feature a suite of advanced instruments including imagers, multi-object spectrographs, high-resolution spectrographs, integral-field spectroscopy and world-leading laser guide star adaptive optics systems.

DEIMOS (the DEep Imaging and Multi-Object Spectrograph) boasts the largest field of view (16.7 arcmin by 5 arcmin) of any of the Keck instruments, and the largest number of pixels (64 Mpix).

It is used primarily in its multi-object mode, obtaining simultaneous spectra of up to 130 galaxies or stars.

Astronomers study fields of distant galaxies with DEIMOS, efficiently probing the most distant corners of the universe with high sensitivity.

ESA XMM-Newton: Cosmic Collision in the Bullett Group

Composite image taken by ESA's XMM-Newton of the Bullet Group showing galaxies, hot gas (shown in pink) and dark matter (indicated in blue). 

Credit: ESA / XMM-Newton / F. Gastaldello (INAF/IASF, Milano, Italy) / CFHTLS

Galaxies are not as isolated as they at first glance may seem; on a cosmic scale they congregate in clumps along with dark matter and hot gas.

The colourful blob in this new composite image, based on data from several telescopes including ESA's XMM-Newton, is the group of galaxies known as the Bullet Group.

Its components appear to be clearly separated, with the hot gas partitioned from the rest of the mass within the group.

This is the smallest object ever found to show such an effect, which was caused by a merger in the group's past.

NASA COSmIC Simulator Recreates Space Dust

Scanning Electron Microscope image of a large (approximately 1.5 micrometer diameter) aggregate of nanograins produced in the Cosmic Simulation Chamber (COSmIC) at NASA's Ames Research Center, using a 95 percent Ar - 5% C2H2 gas mixture. 

The nanograins and aggregates are deposited onto ultra-high vacuum aluminum foil. 

Image courtesy NASA/Ames/Farid Salama.

A team of scientists at NASA's Ames Research Center in Moffett Field, Calif., has successfully reproduced, right here on Earth, the processes that occur in the atmosphere of a red giant star and lead to the formation of planet-forming interstellar dust.

Using a specialist facility, called the Cosmic Simulation Chamber (COSmIC) designed and built at Ames, scientists now are able to recreate and study in the laboratory dust grains similar to the grains that form in the outer layers of dying stars.

Scientists plan to use the dust to gather clues to better understand the composition and the evolution of the universe.

Dust grains that form around dying stars and are ejected into the interstellar medium lead, after a life cycle spanning millions of years, to the formation of planets and are a key component of the universe's evolution.

Scientists have found the materials that make up the building blocks of the universe are much more complicated than originally anticipated.

"The harsh conditions of space are extremely difficult to reproduce in the laboratory, and have long hindered efforts to interpret and analyze observations from space," said Farid Salama, project leader and a space science researcher at Ames.

"Using the COSmIC simulator we can now discover clues to questions about the composition and the evolution of the universe, both major objectives of NASA's space research program."

In the past, the inability to simulate space conditions in the gaseous state prevented scientists from identifying unknown matter.

Because conditions in space are vastly different from conditions on Earth, it is challenging to identify extraterrestrial materials.

Thanks to COSmIC, researchers can successfully simulate gas-phase environments similar to interstellar clouds, stellar envelopes or planetary atmospheres environments by expanding gases using a cold jet spray of argon gas seeded with hydrocarbons that cools down the molecules to temperatures representative of these environments.

COSmIC integrates a variety of state-of-the-art instruments to allow scientists to recreate space conditions in the laboratory to form, process and monitor simulated planetary and interstellar materials.

The chamber is the heart of the system. It recreates the extreme conditions that reign in space where interstellar molecules and ions float in a vacuum at densities that are billionths of Earth's atmosphere, average temperatures can be less than -270 degrees Fahrenheit (about 100 degrees Kelvin), and the environment is bathed in ultraviolet and visible radiation emanating from nearby stars.

"By using COSmIC and building up on the work we recently published in the Astrophysical Journal August 29, 2013, we now can for the first time truly recreate and visualize in the laboratory the formation of carbon grains in the envelope of stars and learn about the formation, structure and size distribution of stellar dust grains," said Cesar Contreras of the Bay Area Environmental Research (BAER) Institute and a research fellow at Ames.

"This type of new research truly pushes the frontiers of science toward new horizons, and illustrates NASA's important contribution to science."

The team started with small hydrocarbon molecules that it expanded in the cold jet spray in COSmIC and exposed to high energy in an electric discharge.

They detected and characterized the large molecules that are formed in the gas phase from these precursor molecules with highly sensitive detectors, then collected the individual solid grains formed from these complex molecules and imaged them using the Ames Scanning Electron Microscope (SEM) (Hitachi S4800 Field Emission SEM).

"During COSmIC experiments, we are able to form and detect nanoparticles on the order of 10 nm size, grains ranging from 100-500 nanometers and aggregates of grains up to 1.5 micrometers in diameter, about a tenth the width of a human hair, and observe their structure with SEM, thus sampling a large size distribution of the grains produced," said Ella Sciamma-O'Brien, of the BAER Institute and a research fellow at Ames.

These results have important implications and ramifications not only for interstellar astrophysics, but also for planetary science.

For example, they can provide new clues on the type of grains present in the dust around stars.

That in turn, will help us understand the formation of planets, including Earth-like planets.

They also will help interpret astronomical data from the ESA Herschel Space Observatory, the Stratospheric Observatory for Infrared Astronomy (SOFIA) and ESO's ALMA, the ground-based Atacama Large Millimeter/submillimeter Array (ALMA) observatory in Chile.

"Today we are celebrating a major milestone in our understanding of the formation and the nature of cosmic dust grains that bears important implications in this new era of exoplanets discoveries," concluded Salama.

Heavy Metal in the Early Cosmos - Simulation

This simulation shows heavy-element-bearing sheets of an exploding star's debris streaming into the center of a cosmic dark matter halo. 

Upon arriving in the center, the streams will enable the formation of the first low-mass stars, when the universe was still only about 200 million years old. 

Image courtesy Jeremy Ritter, Milos Milosavljevic, and Volker Bromm, The University of Texas at Austin.

Ab initio: "From the beginning." It's a term used in science to describe calculations that rely on established mathematical laws of nature, or "first principles," without additional assumptions or special models.

Milos Milosavljevic

But when it comes to the phenomena that Milos Milosavljevic is interested in calculating, we're talking really ab initio, as in from the beginning of time onward.

Things were different in the early eons of the universe.

The cosmos experienced rapid inflation; electrons and protons floated free from each other; the universe transitioned from complete darkness to light; and enormous stars formed and exploded to start a cascade of events leading to our present-day universe.

Working with Chalence Safranek-Shrader and Volker Bromm at the University of Texas at Austin, Milosavljevic recently reported the results of several massive numerical simulations charting the forces of the universe in its first hundreds of millions of years using some of the world's most powerful supercomputers, including the National Science Foundation (NSF) -supported Stampede, Lonestar and Ranger (now retired) systems at the Texas Advanced Computing Center.

The results, described in the Monthly Notices of the Royal Astronomical Society in January 2014, refine how the first galaxies formed, and in particular, how metals in the stellar nurseries influenced the characteristics of the stars in the first galaxies.

"The universe formed at first with just hydrogen and helium," Milosavljevic said. "But then the very first stars cooked metals and after those stars exploded, the metals were dispersed into ambient space."

This simulation shows hydrodynamic instability triggered by rapid cooling in a heavy-element-enriched cosmic dark matter halo when the universe was only 300 million years old.

The instability drives turbulence which breaks the flow into fragments. 

Some fragments undergo gravitational collapse and set to fragment into progressively smaller units. 

From left to right and top to bottom, the six panels show projections of gas density, and the horizontal bar has length 1 pc = 3.26 light years.

Credit: Chalence Safranek-Shrader, Milos Milosavljevic, and Volker Bromm, the University of Texas at Austin

More Information: 'Heavy metal in the early cosmos' Monthly Notices of the Royal Astronomical Society in January 2014 - Milos Milosavljevic, Chalence Safranek-Shrader and Volker Bromm

Early universe 'warmed up' later than previously believed

A new study from Tel Aviv University reveals that black holes, formed from the first stars in our universe, heated the gas throughout space later than previously thought. 

They also imprinted a clear signature in radio waves which astronomers can now search for. 

The work is a major new finding about the origins of the universe.

"One of the exciting frontiers in astronomy is the era of the formation of the first stars," explains Prof. Rennan Barkana of TAU's School of Physics and Astronomy, an author of the study.

Rennan Barkana

"Since the universe was filled with hydrogen atoms at that time, the most promising method for observing the epoch of the first stars is by measuring the emission of hydrogen using radio waves."

The study, just published in the journal Nature, was co-authored by Dr. Anastasia Fialkov of TAU and the École Normale Supérieure in Paris and Dr. Eli Visbal of Columbia and Harvard Universities.

Cosmic archaeology
Astronomers explore our distant past, billions of years back in time. Unlike Earth-bound archaeologists, however, who can only study remnants of the past, astronomers can see the past directly.

The light from distant objects takes a long time to reach the earth, and astronomers can see these objects as they were back when that light was emitted.

Anastasia Fialkov

This means that if astronomers look out far enough, they can see the first stars as they actually were in the early universe.

Thus, the new finding that cosmic heating occurred later than previously thought means that observers do not have to search as far, and it will be easier to see this cosmic milestone.

Cosmic heating may offer a way to directly investigate the earliest black holes, since it was likely driven by star systems called "black-hole binaries."

These are pairs of stars in which the larger star ended its life with a supernova explosion that left a black-hole remnant in its place.

Gas from the companion star is pulled in towards the black hole, gets ripped apart in the strong gravity, and emits high-energy X-ray radiation.

This radiation reaches large distances, and is believed to have re-heated the cosmic gas, after it had cooled down as a result of the original cosmic expansion.

The discovery in the new research is the delay of this heating.

More information: 'The observable signature of late heating of the Universe during cosmic reionization' dx.doi.org/10.1038/nature12999

Amateur Astronomer Catches Cosmic 'Tadpoles' in Celestial Sea

Emission nebula IC 410 lies roughly 12,000 light-years from Earth in the constellation Auriga. Astrophotographer Steve Coates of Ocala, Fla. captured this photo on Dec. 1, 2013.

Credit: Steve Coates

ESA NASA Hubble Image: Cosmic Caterpillar

This light-year-long knot of interstellar gas and dust resembles a caterpillar on its way to a feast. 

But the meat of the story is not only what this cosmic caterpillar eats for lunch, but also what's eating it. 

Harsh winds from extremely bright stars are blasting ultraviolet radiation at this 'wanna-be' star and sculpting the gas and dust into its long shape.

Credit: ESA NASA Hubble

IceCube Detector under Antarctic ice may have seen first cosmic neutrinos

IceCube, the giant experiment buried beneath the South Pole's ice has recorded the first neutrinos ever detected originating outside our solar system, researchers say.

Neutrinos are produced in our atmosphere but the IceCube experiment -- a cubic kilometer of sensitive detectors sunk into the Antarctic ice -- has seen the first "cosmic neutrinos," they said.

IceCube consists of 86 strings, each with 60 sensitive light detectors strung along it like "fairy lights," sunk deep into the ice.

Rare collisions of neutrinos with the nuclei of atoms in the ice produce a brief flash that the detectors can catch.

With more than 5,000 detectors catching the flashes the direction of the neutrinos' arrival on Earth can be determined, the researchers said.

Neutrinos can be produced in the Earth's atmosphere -- IceCube picks up about 100,000 of that variety a year -- but previous attempts to isolate neutrinos created in far-flung cosmic processes had all failed.

However, in April the IceCube research team reported detecting two neutrinos -- nicknamed Bert and Ernie -- with energy levels high enough to suggest a cosmic rather than atmospheric origin.

The team has now reported 26 more events of similar energy that they expect will also be confirmed as cosmic in origin.

Francis Halzen

Detection is just a first step and "of course, there's much more to do," IceCube principle investigator Francis Halzen told reporters.

"It's after you find them that the work starts; these events are very difficult to analyze."

The study results were presented Wednesday at the IceCube Particle Astrophysics Symposium in Madison, Wis.

Kepler Supernova: Crucial Cosmic Distance Markers

This is the remnant of Kepler's supernova, the famous explosion that was discovered by Johannes Kepler in 1604. 

The red, green and blue colors show low, intermediate and high energy X-rays observed with NASA's Chandra X-ray Observatory, and the star field is from the Digitized Sky Survey. 

Credit: X-ray: NASA/CXC/NCSU/M.Burkey et al; Optical: DSS

A new study using data from NASA's Chandra X-ray Observatory points to the origin of a famous supernova.

This supernova, discovered in 1604 by Johannes Kepler, belongs to an important class of objects that are used to measure the rate of expansion of the Universe.

Astronomers have used a very long Chandra observation of the remnant of Kepler’s supernova to deduce that the supernova was triggered by an interaction between a white dwarf and a red giant star.

This is significant because another study has already shown that a so-called Type Ia supernova caused the Kepler supernova remnant.

The thermonuclear explosion of a white dwarf star produces such supernovas. Because they explode with nearly uniform brightness, astronomers have used them as cosmic distance markers to track the accelerated expansion of the Universe.

However, there is an ongoing controversy about Type Ia supernovas. Are they caused by a white dwarf pulling so much material from a companion star that it becomes unstable and explodes? Or do they result from the merger of two white dwarfs?

Mary Burkey

"While we can't speak to all Type Ia supernovas, our evidence points to Kepler being caused by a white dwarf pulling material from a companion star, and not the merger of two white dwarfs," said the first author of the new Chandra study, Mary Burkey of North Carolina State University (NCSU).

"To continue improving distance measurements with these supernovas, it is crucial to understand how they are triggered."

The Kepler supernova remnant is one of only a few Type Ia supernovas known to have exploded in the Milky Way galaxy. Its proximity and its identifiable explosion date make it an excellent object to study.

Stephen Reynolds

“Johannes Kepler made such good naked-eye observations in 1604 that we can identify the supernova as Type Ia,” said co-author Stephen Reynolds, also of NCSU. “He would be thrilled that we can use today’s terrific instruments to reveal the hidden secrets of his supernova.”

The new Chandra images reveal a disk-shaped structure near the center of the remnant. The researchers interpret this X-ray emission to be caused by the collision between supernova debris and disk-shaped material that the giant star expelled before the explosion. Another possibility is that the structure is just debris from the explosion.

The evidence that this disk-shaped structure was left behind by the giant star is two-fold: first, a substantial amount of magnesium – an element not produced in great amounts in Type Ia supernovas – was found in the Kepler remnant. This suggests the magnesium came from the giant companion star.

Secondly, the disk structure seen by Chandra in X-rays bears a remarkable resemblance in both shape and location to one observed by the Spitzer Space Telescope.

These infrared-emitting disks are thought to be dusty bands expelled by stars in a wind, rather than material ejected in a supernova.

The researchers found a remarkably large and puzzling concentration of iron on one side of the center of the remnant but not the other.

Kazimierz Borkowski

The authors speculate that the cause of this asymmetry might be the "shadow" in iron that was cast by the companion star, which blocked the ejection of material.

Previously, theoretical work has suggested this shadowing is possible for Type Ia supernova remnants.

“One remaining challenge is to find the damaged and fast-moving leftovers of the giant star that was pummeled by the explosion at close quarters,” said co-author Kazimierz Borkowski, also of NCSU.

The above story is reprinted from materials provided by Chandra X-ray Observatory.

ESA Hubble Image: Cosmic "Flying V" of Merging Galaxies

Image courtesy ESA/Hubble and NASA.

This large "flying V" is actually two distinct objects - a pair of interacting galaxies known as IC 2184.

Both the galaxies are seen almost edge-on in the large, faint northern constellation of Camelopardalis (The Giraffe), and can be seen as bright streaks of light surrounded by the ghostly shapes of their tidal tails.

These tidal tails are thin, elongated streams of gas, dust and stars that extend away from a galaxy into space.

They occur when galaxies gravitationally interact with one another, and material is sheared from the outer edges of each body and flung out into space in opposite directions, forming two tails.

They almost always appear curved, so when they are seen to be relatively straight, as in this image, it is clear that we are viewing the galaxies side-on.

Also visible in this image are bursts of bright blue, pinpointing hot regions where the colliding gas clouds stir up vigorous star formation.

The image consists of visible and infrared observations from Hubble's Wide Field and Planetary Camera 2.

Microsatellites aim to fill weather-data gap

The COSMIC radio-sounding satellites are ageing but may set the stage for a commercial system.

Credit: OSC/UCAR

Some orbiting satellites look up at the stars and most point down towards Earth but the satellites of the Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC) look sideways, across the curving horizon.

There, dozens of satellites that are part of the Global Positioning System (GPS) pop in and out of view at the edge of the planet. By tracking their radio signals, COSMIC can provide atmospheric data that enhance weather forecasts and climate models.

But the fleet, launched six years ago at a cost of US$100 million, is nearing the end of its life, with one satellite of the original six already defunct.

At a three-day workshop last month at the University Corporation for Atmospheric Research (UCAR) in Boulder, Colorado, researchers hailed the US–Taiwanese COSMIC as a pioneer and discussed plans for a commercial successor: a network of 24 micro­satellites dubbed the Community Initiative for Cellular Earth Remote Observation (CICERO).

Researchers say that the programme could help to address a gap in atmospheric data as the United States struggles to meet a 2016 launch date for the first spacecraft in its expensive Joint Polar Satellite System (JPSS).

The radio-sounding technique that both COSMIC and CICERO use is a “disruptive technology”, says Rick Anthes, a COSMIC scientist and former president of UCAR. “The impact is huge — especially the impact for the cost.”

GPS radio signals, picked up by Earth-bound receivers in everything from mobile phones to missiles, yield precise position information. But COSMIC puts them to a different use.

The signals travel at a known rate, but skimming through the planet’s atmosphere and back out to space bends the signals and delays them; COSMIC uses the length of the delay to measure the atmospheric density, which can provide information on changing characteristics such as temperature and moisture levels (see ‘Bending for data’). It makes many hundreds of these radio-occultation measurements each day.

NASA ISS Crew seeing elusive Cosmic Sprites - Rare Video

A sprite glows red (inset) in this image captured by astronauts on the International Space Station on April 30, 2012.   

Credit: Image Science & Analysis Laboratory, NASA Johnson Space Center 

High above the clouds during thunderstorms, some 50 miles above Earth a different kind of lightning dances.

Bursts of red and blue light, known as "sprites," flash for a scant one thousandth of a second. They are often only visible to those in flight above a storm, and happen so quickly you might not even see it unless you chance to be looking directly at it.

One hard-to-reach place that gets a good view of sprites is the International Space Station. On April 30, 2012, astronauts on the ISS captured the signature red flash of a sprite, offering the world and researchers a rare opportunity to observe one.

Filmed at 10,000 frames per second by Japan's NHK television, movies like this of electromagnetic bursts called "sprites" will help scientists better understand how weather high in the atmosphere relates to weather on the ground. 

Credit: NHK

Indeed, sprites are so hard to catch on film, that pilots had claimed to see them for almost a century before scientists at the University of Minnesota accidentally caught one on camera in July of 1989.

Since then, researchers aboard planes have occasionally snapped a shot, but it continues to be difficult to methodically film them.

So a group of scientists, along with help from Japan's NHK television, sought them out regularly for two weeks in the summer of 2011.

Filming at 10,000 frames per second on two separate jets, the team recorded some of the best movies of sprites ever taken – movies that can be used to study this poorly understood phenomenon and the forces that create them.

By filming from two jets flying 12 miles apart, the team mapped out the 3-dimensional nature of the sprites. Ground-based measurements rounded out the picture.

ESA ESO VLT: Gaseous ring around young star V1052 Centaurus

Artist's conception image of a young star surrounded by a disk (made up of rings) (Credits: NASA/JPL-Caltech)

Astronomers have detected a mysterious ring of carbon monoxide gas around the young star V1052 Cen, which is about 700 light years away in the southern constellation Centaurus.

The ring is part of the star’s planet-forming disk, and it’s as far from V1052 Cen as Earth is from the sun. Discovered with the European Southern Observatory's Very Large Telescope, its edges are uniquely crisp.

Carbon monoxide is often detected near young stars, but the gas is usually spread through the planet-forming disk. What’s different about this ring is that it is shaped more like a rope than a dinner plate, said Charles Cowley, professor emeritus in the University of Michigan who led the international research effort.

“It’s exciting because this is the most constrained ring we've ever seen, and it requires an explanation,” Cowley said. “At present time, we just don't understand what makes it a rope rather than a dish.”

Perhaps magnetic fields hold it in place, the researchers say. Maybe “shepherding planets” are reining it in like several of Saturn’s moons control certain planetary rings.

“What makes this star so special is its very strong magnetic field and the fact that it rotates extremely slow compared to other stars of the same type,” said Swetlana Hubrig, of the Leibniz Institute for Astrophysics Potsdam (AIP), Germany.

The star’s unique properties first caught the researchers’ attention in 2008, and they have been studying it intensely ever since.

Understanding the interaction between central stars, their magnetic fields, and planet-forming disks is crucial for astronomers to reconstruct the solar system's history.

It is also important to account for the diversity of the known planetary systems beyond our own. This new finding raises more questions than it answers about the late stages of star and solar system formation.

“Why do turbulent motions not tear the ring apart?” Cowley wondered. “How permanent is the structure? What forces might act to preserve it for times comparable to the stellar formation time itself?”

The team is excited to have found an ideal test case to study this type of object.

“This star is a gift of nature,” Hubrig said.

The findings are newly published online in Astronomy and Astrophysics. The paper is titled “The narrow, inner CO ring around the magnetic Herbig Ae star HD 101412.”

Authors are from the University of Michigan, the Leibniz Institute for Astrophysics Potsdam (AIP) in Germany, the Istituto Nazionale die Astrofisica in Italy and the European Southern Observatory.

ESA ESO: The Helix in New Colours

ESO’s VISTA telescope, at the Paranal Observatory in Chile, has captured a striking new image of the Helix Nebula. 

This picture, taken in infrared light, reveals strands of cold nebular gas that are invisible in images taken in visible light, as well as bringing to light a rich background of stars and galaxies.

The Helix Nebula is one of the closest and most remarkable examples of a planetary nebula.

It lies in the constellation of Aquarius (The Water Bearer), about 700 light-years away from Earth.

This strange object formed when a star like the Sun was in the final stages of its life.

Unable to hold onto its outer layers, the star slowly shed shells of gas that became the nebula. It is evolving to become a white dwarf star and appears as the tiny blue dot seen at the centre of the image.

The nebula itself is a complex object composed of dust, ionised material as well as molecular gas, arrayed in a beautiful and intricate flower-like pattern and glowing in the fierce glare of ultraviolet light from the central hot star.

The main ring of the Helix is about two light-years across, roughly half the distance between the Sun and the nearest star. However, material from the nebula spreads out from the star to at least four light-years.

This is particularly clear in this infrared view since red molecular gas can be seen across much of the image.

While hard to see visually, the glow from the thinly spread gas is easily captured by VISTA’s special detectors, which are very sensitive to infrared light.

The 4.1-metre telescope is also able to detect an impressive array of background stars and galaxies.

The powerful vision of ESO’s VISTA telescope also reveals fine structure in the nebula’s rings. The infrared light picks out how the cooler, molecular gas is organised.

The material clumps into filaments that radiate out from the centre and the whole view resembles a celestial firework display.

Even though they look tiny, these strands of molecular hydrogen, known as cometary knots, are about the size of our Solar System.

The molecules in them are able to survive the high-energy radiation that emanates from the dying star precisely because they clump into these knots, which in turn are shielded by dust and molecular gas. It is currently unclear how the cometary knots may have originated.

Astronomers release unprecedented data set on celestial objects that brighten and dim

This is an image of a dwarf nova, which is a star system where material flows from a red giant star to a dense, compact star called a white dwarf. 

The flowing material triggers explosions that cause the system to flare up as seen from Earth.

The graph shows the change in brightness of this system over a period of seven years. 

The images at the top show the nova at its brightest and dimmest, as indicated in the plot. 

Such systems are important for understanding stellar evolution, and the CRTS team has discovered nearly a thousand of them‑‑more than any other survey. 

Credit: The CRTS Survey Team, Caltech

NASA WISE Image: Cosmic clouds bubbling with new star birth

A new, large mosaic from NASA's Wide-Field Infrared Survey Explorer (WISE) showcases a vast stretch of cosmic clouds bubbling with new star birth.

The region - a 1,000-square-degree chunk of our Milky Way galaxy - is home to numerous star-forming clouds, where massive stars have blown out bubbles in the gas and dust.

"Massive stars sweep up and destroy their natal clouds, but they continuously spark new stars to form along the way," said WISE Mission Scientist Dave Leisawitz of NASA Goddard Space Flight Center, Greenbelt, Md. Leisawitz is co-author of a new paper reporting the results in the Astrophysical Journal.

"Occasionally a new, massive star forms, perpetuating the sequence of events and giving rise to the dazzling fireworks display seen in this WISE mosaic."

The WISE space telescope mapped the entire sky two times in infrared light, completing its survey in February of 2011. Astronomers studying how stars form took advantage of WISE's all-encompassing view by studying several star-forming clouds, or nebulae, including 10 pictured in this new view.

The observations provide new evidence for a process called triggered star formation, in which the winds and sizzling radiation from massive stars compress gas and dust, inducing a second generation of stars. The same winds and radiation carve out the cavities, or bubbles, seen throughout the image.

Finding evidence for triggered star formation has proved more difficult than some might think. Astronomers are not able to watch the stars grow and evolve like biologists watching zebras in the wild.

Instead, they piece together a history of star formation by looking at distinct stages in the process. It's the equivalent of observing only baby, middle-aged and elderly zebras with crude indicators of their ages. WISE is helping to fill in these gaps by providing more and more "specimens" for study.

"Each region we looked at gave us a single snapshot of star formation in progress," said Xavier Koenig, lead author of the new study at Goddard, who presented the results in Austin, Texas, at the 219th meeting of the American Astronomical Society. "But when we look at a whole collection of regions, we can piece together the chain of events."

After looking at several of the star-forming nebulae, Koenig and his colleagues noticed a pattern in the spatial arrangement of newborn stars. Some were found lining the blown-out cavities, a phenomenon that had been seen before, but other new stars were seen sprinkled throughout the cavity interiors.

The results suggest that stars are born in a successive fashion, one after the other, starting from a core cluster of massive stars and moving steadily outward. This lends support to the triggered star formation theory, and offers new clues about the physics of the process.

The astronomers also found evidence that the bubbles seen in the star-forming clouds can spawn new bubbles. In this scenario, a massive star blasts away surrounding material, eventually triggering the birth of another star massive enough to carve out its own bubble. A few examples of what may be first- and second-generation bubbles can be seen in the new WISE image.

"I can almost hear the stars pop and crackle," said Leisawitz.

Purple Haze: Dumbbell Nebula

A purple glow seems to burst out of space in this stunning image of a cosmic gas cloud by skywatcher Bill Snyder.

The photo depicts the Dumbbell Nebula, also known as M27, seen near the constellation of Vulpecula or "Little Fox."

M27 is a planetary nebula. This is a type of emission nebula that forms when a star dies and emits a glowing shell of gas. In the distant future — more than 6 billion hers from now — our sun will likely puff off its outer layers to create a planetary nebula.

In the photo, the nebula shines in two bright colors: The purple central glow is surrounded by a blue, hazy halo. These hues are due to hyrdogen and oxygen gas that has been ejected from the star out into space.

This nebula is more than 1,200 light-years away (a light-year is the distance light travels in one year — about 6 trillion miles, or 10 trillion kilometers). For avid skywatchers, the nebula can be easily seen through an amateur telescope, and has an apparent magnitude of 7.5. On this scale, smaller numbers represent brighter objects. The dimmest objects visible to the human eye are about magnitude 6.5.

Einstein Ring Hubble Image: Cosmic Horseshoe seems to surround Red galaxy

A fortuitous alignment of celestial mechanics has given the Hubble Space Telescope an amazing view of some distant galaxies.

Here, one interesting red galaxy is encircled by a hazy blue horseshoe shape and contains about 10 times the mass of our Milky Way galaxy.

It's actually the blue horsehoe shape that has astronomers talking about this photo.

The horseshoe is actually a distant galaxy that has been magnified and warped into a nearly complete ring by the strong gravitational pull of the massive red galaxy in the foreground.

To see such a so-called Einstein Ring required the fortunate alignment of the foreground and background galaxies, making this object’s nickname "the Cosmic Horseshoe" particularly apt, NASA says.