ALMA Archives

July 29, 2013December 23, 2015 by Elizabeth Howell

Astronomers See Snow … In Space!

Artist's conception of the snow line in TW Hydrae. Credit: Bill Saxton/Alexandra Angelich, NRAO/AUI/NSF

There’s an excellent chance of frost in this corner of the universe: astronomers have spotted a “snow line” in a baby solar system about 175 light-years away from Earth. The find is cool (literally and figuratively) in itself. More importantly, however, it could give us clues about how our own planet formed billions of years ago.

“[This] is extremely exciting because of what it tells us about the very early period in the history of our own solar system,” stated Chunhua Qi, a researcher with the Harvard-Smithsonian Center for Astrophysics who led the research.

“We can now see previously hidden details about the frozen outer reaches of another solar system, one that has much in common with our own when it was less than 10 million years old,” he added.

The real deal enhanced-color picture of TW Hydrae is below, courtesy of a newly completed telescope: the Atacama Large Millimeter/submillimeter Array in Chile. It is designed to look at grains and other debris around forming solar systems. This snow line is huge, stretching far beyond the equivalent orbit of Neptune in our own solar system. See the circle? That’s Neptune’s orbit. The green stuff is the snow line. Look just how far the green goes past the orbit.

The carbon monoxide line as seen by the Atacama Large Millimeter/submillimeter Array (ALMA) telescope. The circle represents the equivalent orbit of Neptune when comparing it to our own solar system. Credit: Karin Oberg, Harvard University/University of Virginia — The carbon monoxide line on TW Hydrae as seen by the Atacama Large Millimeter/submillimeter Array (ALMA) telescope. The circle represents the equivalent orbit of Neptune when comparing it to our own solar system. Credit: Karin Oberg, Harvard University/University of Virginia

Young stars are typically surrounded by a cloud of gas and debris that, astronomers believe, can in many cases form into planets given enough time. Snow lines form in young solar systems in areas where the heat of the star isn’t enough to melt the substance. Water is the first substance to freeze around dust grains, followed by carbon dioxide, methane and carbon monoxide.

It’s hard to spot them: “Snow lines form exclusively in the relatively narrow central plane of a protoplanetary disk. Above and below this region, stellar radiation keeps the gases warm, preventing them from forming ice,” the astronomers stated. In areas where dust and gas are more dense, the substances are insulated and can freeze — but it’s difficult to see the snow through the gas.

In this case, astronomers were able to spot the carbon monoxide snow because they looked for diazenylium, a molecule that is broken up in areas of carbon monoxide gas. Spotting it is a “proxy” for spots where the CO froze out, the astronomers said.

Here are some more of the many reasons this is exciting to astronomers:

Snow could help dust grains form faster into rocks and eventually, planets because it coats the grain surface into something more stickable;
Carbon monoxide is a requirement to create methanol, considered a building block of complex molecules and life;
The snow was actually spotted with only a small portion of ALMA’s 66 antennas while it was still under construction. Now that ALMA is complete, scientists are already eager to see what the telescope will turn up the next time it gazes at the system.

Source: National Radio Astronomy Observatory

July 10, 2013December 23, 2015 by Jason Major

ALMA Spots a Nascent Stellar Monster

ALMA/Spitzer image of a monster star in the process of forming

Even though it comprises over 99% of the mass of the Solar System (with Jupiter taking up most of the rest) our Sun is, in terms of the entire Milky Way, a fairly average star. There are lots of less massive stars than the Sun out there in the galaxy, as well as some real stellar monsters… and based on new observations from the Atacama Large Millimeter/submillimeter Array, there’s about to be one more.

Early science observations with ALMA have provided astronomers with the best view yet of a monster star in the process of forming within a dark cloud of dust and gas. Located 11,000 light-years away, Spitzer Dark Cloud 335.579-0.292 is a stellar womb containing over 500 times the mass of the Sun — and it’s still growing. Inside this cloud is an embryonic star hungrily feeding on inwardly-flowing material, and when it’s born it’s expected to be at least 100 times the mass of our Sun… a true stellar monster.

The location of SDC 335.579-0.292 in the southern constellation of Norma (ESO, IAU and Sky & Telescope)

The star-forming region is the largest ever found in our galaxy.

“The remarkable observations from ALMA allowed us to get the first really in-depth look at what was going on within this cloud,” said Nicolas Peretto of CEA/AIM Paris-Saclay, France, and Cardiff University, UK. “We wanted to see how monster stars form and grow, and we certainly achieved our aim! One of the sources we have found is an absolute giant — the largest protostellar core ever spotted in the Milky Way.”

Watch: What’s the Biggest Star in the Universe?

SDC 335.579-0.292 had already been identified with NASA’s Spitzer and ESA’s Herschel space telescopes, but it took the unique sensitivity of ALMA to observe in detail both the amount of dust present and the motion of the gas within the dark cloud, revealing the massive embryonic star inside.

“Not only are these stars rare, but their birth is extremely rapid and their childhood is short, so finding such a massive object so early in its evolution is a spectacular result.”

– Team member Gary Fuller, University of Manchester, UK

The image above, a combination of data acquired by both Spitzer and ALMA (see below for separate images) shows tendrils of infalling material flowing toward a bright center where the huge protostar is located. These observations show how such massive stars form — through a steady collapse of the entire cloud, rather than through fragmented clustering.

SDC 335.579-0.292 seen in different wavelengths of light.

“Even though we already believed that the region was a good candidate for being a massive star-forming cloud, we were not expecting to find such a massive embryonic star at its center,” said Peretto. “This object is expected to form a star that is up to 100 times more massive than the Sun. Only about one in ten thousand of all the stars in the Milky Way reach that kind of mass!”

(Although, with at least 200 billion stars in the galaxy, that means there are still 20 million such giants roaming around out there!)

Should This Alien World Even Exist? This Young Disk Could Challenge Planet-Formation Theories

An image of TW Hydrae and the protoplanetary stuff surrounding the star. Astronomers believe a planet is forming within the gas and dust and sweeping up debris, as shown by the gap in this picture. Credit: NASA, ESA, J. Debes (STScI), H. Jang-Condell (University of Wyoming), A. Weinberger (Carnegie Institution of Washington), A. Roberge (Goddard Space Flight Center), and G. Schneider (University of Arizona/Steward Observatory)

Take a close look at the blurry image above. See that gap in the cloud? That could be a planet being born some 176 light-years away from Earth. It’s a small planet, only 6 to 28 times Earth’s mass.

That’s not even the best part.

This alien world, if we can confirm it, shouldn’t be there according to conventional planet-forming theory.

The gap in the image above — taken by the Hubble Space Telescope — probably arose when a planet under construction swept through the dust and debris in its orbit, astronomers said.

That’s not much of a surprise (at first blush) given what we think we know about planet formation. You start with a cloud of debris and gas swirling around a star, then gradually the bits and pieces start colliding, sticking together and growing bigger into small rocks, bigger ones and eventually, planets or gas giant planet cores.

But there’s something puzzling astronomers this time around: this planet is a heck of a long way from its star, TW Hydrae, about twice Pluto’s distance from the sun. Given that alien systems’ age, that world shouldn’t have formed so quickly.

An illustration of TW Hydrae's disk in comparison with that of Earth's solar system. Credit: NASA, ESA, and A. Feild (STScI) — An illustration of TW Hydrae’s disk in comparison with that of Earth’s solar system. Credit: NASA, ESA, and A. Feild (STScI)

Astronomers believe that Jupiter took about 10 million years to form at its distance away from the sun. This planet near TW Hydrae should take 200 times longer to form because the alien world is moving slower, and has less debris to pick up.

But something must be off, because TW Hydrae‘s system is believed to be only 8 million years old.

“There has not been enough time for a planet to grow through the slow accumulation of smaller debris. Complicating the story further is that TW Hydrae is only 55 percent as massive as our sun,” NASA stated, adding it’s the first time we’ve seen a gap so far away from a low-mass star.

The lead researcher put it even more bluntly: “Typically, you need pebbles before you can have a planet. So, if there is a planet and there is no dust larger than a grain of sand farther out, that would be a huge challenge to traditional planet formation models,” stated John Debes, an astronomer at the Space Telescope Science Institute in Baltimore.

Protoplanet Hypothesis — Like a raindrop forming in a cloud, a star forms in a diffuse gas cloud in deep space. As the star grows, its gravitational pull draws in dust and gas from the surrounding molecular cloud to form a swirling disk called a “protoplanetary disk.” This disk eventually further consolidates to form planets, moons, asteroids and comets. Credit: NASA/JPL-Caltech

At this point, you would suppose the astronomers are seriously investigating other theories. One alternative brought up in the press release: perhaps part of the disc collapsed due to gravitational instability. If that is the case, a planet could come to be in only a few thousand years, instead of several million.

“If we can actually confirm that there’s a planet there, we can connect its characteristics to measurements of the gap properties,” Debes stated. “That might add to planet formation theories as to how you can actually form a planet very far out.”

A rare double transit of Jupiter's moon Ganymede (top) and Io on Jan. 3, 2013. Here, the sun is shining from the left causing shadows cast by the moons to fall onto the planet's cloud tops. Credit: Damian Peach — A rare double transit of Jupiter’s moon Ganymede (top) and Io on Jan. 3, 2013. Here, the sun is shining from the left causing shadows cast by the moons to fall onto the planet’s cloud tops. Credit: Damian Peach

There’s a trick with the “direct collapse” theory, though: astronomers believe it takes a bunch of matter that is one to two times more massive than Jupiter before a collapse can occur to form a planet.

Recall that this world is no more than 28 times the mass of Earth, as best as we can figure. Well, Jupiter itself is 318 times more massive than Earth.

There are also intriguing results about the gap. Chile’s Atacama Large Millimeter/submillimeter Array (ALMA) — which is designed to look at dusty regions around young stars — found that the dust grains in this system, orbiting nearby the gap, are still smaller than the size of a grain of sand.

Astronomers plan to use ALMA and the James Webb Space Telescope, which should launch in 2018, to get a better look. In the meantime, the results will be published in the June 14 edition of the Astrophysical Journal.

Source: HubbleSite

June 6, 2013December 23, 2015 by Tammy Plotner

ALMA and the Comet Factory

This artist’s impression shows the dust trap in the system Oph-IRS 48. The dust trap provides a safe haven for the tiny rocks in the disc, allowing them to clump together and grow to sizes that allow them to survive on their own. Credit: ESO/L. Calçada

“Ooompah, loompah, roopity rust… ALMA finds comets hiding in dust.” According to many studies over recent years, astronomers are aware planets seem to be everywhere around stars. However, just how these rocky bodies, including comets, are created is something of an enigma. Now, thanks to one sweet telescope, the Atacama Large Millimeter/submillimeter Array (ALMA), science has taken a big step forward in understanding how minuscule dust grains in a protoplanetary disk can one day evolve into a larger format.

A little less than 400 light years from Earth is a youthful solar system cataloged as Oph IRS 48. In images taken of its outer perimeters, astronomers have picked up a vital clue in its swirling masses of dust – a crescent-shaped region dubbed a “dust trap”. Researchers feel this area may be a protective cocoon which allows rocky formations to take shape. Why is such a region important? It’s the smash-factor. When astronomers try to model dust to rocky formations, they have found the particles self-destruct… either by crashing into each other, or being drawn into the central star. In order for them to progress past a certain size, they simply must have an area of protection to allow them to grow.

“There is a major hurdle in the long chain of events that leads from tiny dust grains to planet-sized objects,” said Til Birnstiel, a researcher at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., and co-author on the paper published in the journal Science. “In computer models of planet formation, dust grains must grow from submicron sizes to objects up to ten times the mass of the Earth in just a few million years. But once particles grow larger enough, they begin to pick up speed and either collide, sending them back to square one, or slowly drift inward, thwarting further growth.”

So where can a newborn planet, comet or asteroid hide? Nienke van der Marel, a PhD student at Leiden Observatory in the Netherlands, and lead author of the article, was using ALMA along with her co-workers, to take a close look at Oph IRS 48 and discovered a torus of gas with a central hole. This absence of dust particles was very different from earlier results picked up on ESO’s Very Large Telescope.

“At first the shape of the dust in the image came as a complete surprise to us,” says van der Marel. “Instead of the ring we had expected to see, we found a very clear cashew-nut shape! We had to convince ourselves that this feature was real, but the strong signal and sharpness of the ALMA observations left no doubt about the structure. Then we realised what we had found.”

A surprise? You bet. What the team uncovered was a region where large dust grains remained captive and could continue to gain mass as more and more grains collided and melded together. Here was the “dust trap” which theorists predicted.

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So what makes it up? To keep the dust grains together and forming requires a vortex – an area of high pressure to protect them. To form this vortex, there needs to be a large object present, either a companion star or a gas-giant. Like a boat sluicing through algae-filled waters, the secondary object in the planetary disk would clear a path in its wake, producing the critical eddies and vortices needed to fashion the dust trap. While previous studies of Oph IRS 48 uncovered a rigid ring of carbon monoxide gas combined with dust, there was no observed “trap”. However, that doesn’t mean the observation was negative. Astronomers also uncovered a gap between the inner and outer portions of the solar system – a clue to the presence of the necessary large body.

The conditions were right for a possible dust trap. Enter ALMA. Now the researchers were able to see both the gas and larger dust grains at the same time. These new observations led to a discovery no other telescope had yet revealed… a lopsided bulge in the outer portion of the disk.

As van der Marel explains: “It’s likely that we are looking at a kind of comet factory as the conditions are right for the particles to grow from millimetre to comet size. The dust is not likely to form full-sized planets at this distance from the star. But in the near future ALMA will be able to observe dust traps closer to their parent stars, where the same mechanisms are at work. Such dust traps really would be the cradles for new-born planets.”

As larger particles migrate towards the areas of higher pressure, the dust trap takes shape. To validate their findings the researchers employed computer modeling to show that a high pressure region could arise from the motion of the gas at the opening edges. It matches with the observation of the Oph IRS 48 disc.

“The combination of modelling work and high quality observations of ALMA makes this a unique project”, says Cornelis Dullemond from the Institute for Theoretical Astrophysics in Heidelberg, Germany, who is an expert on dust evolution and disc modelling, and a member of the team. “Around the time that these observations were obtained, we were working on models predicting exactly these kinds of structures: a very lucky coincidence.”

“This structure we see with ALMA could be scaled down to represent what may be happening in the inner solar system where more Earth-like rocky planets would form,” said Birnstiel. “In the case of these observations, however, we may be seeing something analogous to the formation of our Sun’s Kuiper Belt or Oort Cloud, the region of our solar system where comets are believed to originate.”

Like that dream factory of our childhood, ALMA is still under construction. These unique observations were taken with the ALMA Band 9 receivers – European-made instrumentation which permits ALMA to deliver its sharpest, most detailed images so far.

“These observations show that ALMA is capable of delivering transformational science, even with less than half of the full array in use,” says Ewine van Dishoeck of the Leiden Observatory, who has been a major contributor to the ALMA project for more than 20 years. “The incredible jump in both sensitivity and image sharpness in Band 9 gives us the opportunity to study basic aspects of planet formation in ways that were simply not possible before.”

Original Story Source: ESO News Release. For further reading: NRAO News Release.

May 28, 2013December 23, 2015 by Elizabeth Howell

Early Galaxies Churned Out Stars Like Crazy

The Southern Cross, the Milky Way, and the Large Magellanic Cloud shine above the Atacama Large Millimeter/submillimeter Array (ALMA) as it observes on a clear night sky during its Early Science phase. Image credit: C. Padilla, NRAO/AUI/NSF

Talk about an assembly line! Some early-stage galaxies created stars thousands of times faster than our Milky Way does today, according to new research. And it’s puzzling astronomers.

“We want to understand how and why these galaxies are forming stars at such incredibly fast rates, so soon after the Big Bang,” stated Scott Chapman of Dalhousie University, one of the researchers behind the discovery. “This could partially answer how our own galaxy, the Milky Way, was born billions of years ago.”

This is just a hint of the high-definition view we’ll receive from Chile’s Atacama Large Millimeter/submillimeter Array (ALMA), its astronomers promise, since the array of dozens of telescopes was officially inaugurated this spring. (ALMA has been working for years, but slowly adding telescopes and definition as it goes.)

There were actually three papers released today about ALMA. So what did the observatory find out this time? Here’s the nut graf:

Gravitational microlensing method requires that you have two stars that lie on a straight line in relation to us here on Earth. Then the light from the background star is amplified by the gravity of the foreground star, which thus acts as a magnifying glass.

– The observed galaxies are “gravitationally lensed”. Galaxies are so massive that they can bend light from other galaxies, if put in the right spot with respect to Earth. We’ve seen this effect over and over again with the Hubble Space Telescope, but observations are less well-known in the millimeter spectrum of light in which ALMA observes. “Models of lens geometries in the sample indicate that the background objects are ultra-luminous infrared galaxies, powered by extreme bursts of star formation,” stated a Nature paper on the discovery.

– These galaxies are further away than we thought. By measuring the time it takes light from carbon monoxide molecules to reach us, the astronomers concluded these galaxies are much further away than previously measured, with some reaching as far back as 12 billion light-years away. (That’s just 1.7 billion years after the Big Bang created the universe.)

– The galaxies put star creation on fast-forward. Looking back that far is like looking in a time machine — we can see things that were happening only 1 billion years after the Big Bang. At the time, those galaxies were as bright as 40 trillion suns and created new stars at an extreme rate of 4,000 suns per year. (That, by the way, is 4,000 times faster than what our own galaxy does.)

You can read more about these results in Nature and the Astrophysical Journal (here and here.)

Source: Canadian Astronomical Society (CASCA)

April 1, 2013December 23, 2015 by Jason Major

A Radio Astronomer’s Paradise

Just a few of ALMA's 66 giant radio telescopes (NRAO)

Last month a dozen journalists from around North America were guests of the National Radio Astronomy Observatory and got to take a trip to the Atacama Desert in Chile to attend the inauguration of the Atacama Large Millimeter/submillimeter Array observatory — ALMA, for short.

It was, in no uncertain terms, a radio astronomer’s paradise.

Join one radio astronomer, Dr. Nicole Gugliucci, on her trip to the 5100-meter-high Chajnantor Plateau to visit the ALMA sites in this video, also featuring NRAO’s Tania Burchell, John Stoke, Charles Blue and the Planetary Society’s Mat Kaplan.

Read about this and more on Nicole’s NoisyAstronomer blog.

ALMA will open a new window on celestial origins, capturing never-before seen details about the very first stars and galaxies in the Universe, probing the heart of our galaxy, and directly imaging the formation of planets. It is the largest leap in telescope technology since Galileo first aimed a lens on the Universe.

March 13, 2013December 23, 2015 by Tammy Plotner

ALMA Eyes Most Distant Star-forming Galaxy

This schematic image represents how light from a distant galaxy is distorted by the gravitational effects of a nearer foreground galaxy, which acts like a lens and makes the distant source appear distorted, but brighter, forming characteristic rings of light, known as Einstein rings. An analysis of the distortion has revealed that some of the distant star-forming galaxies are as bright as 40 trillion Suns, and have been magnified by the gravitational lens by up to 22 times. Credit: ALMA (ESO/NRAO/NAOJ), L. Calçada (ESO), Y. Hezaveh et al.

Let’s turn down the lights and set the stage… We’re moving off through space, looking not only at distant galaxies, but the incredibly distant past. Once upon a time astronomers assumed that star formation began in massive, bright galaxies as a concentrated surge. Now, new observations taken with the Atacama Large Millimeter/submillimeter Array (ALMA) are showing us that these deluges of stellar creation may have begun much earlier than they thought.

According to the latest research published in today’s edition of the journal, Nature, and in the Astrophysical Journal, researchers have revealed fascinating discoveries taken with the new international ALMA observatory – which celebrates its inauguration today. Among its many achievements, ALMA has given us a look even deeper into space – showing us ancient galaxies which may be billions of light years distant. The observations of these starburst galaxies show us that stars were created in a frenzy out of huge deposits of cosmic gas and dust.

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“The more distant the galaxy, the further back in time one is looking, so by measuring their distances we can piece together a timeline of how vigorously the Universe was making new stars at different stages of its 13.7 billion year history,” said Joaquin Vieira (California Institute of Technology, USA), who led the team and is lead author of the paper in the journal Nature.

Just how did these observations come about? Before ALMA, an international team of researchers employed the US National Science Foundation’s 10-metre South Pole Telescope (SPT ) to locate these distant denizens and then homed in on them to take a closer look at the “stellar baby boom” during the Universe’s beginning epoch. What they found surprised them. Apparently star forming galaxies are even more distant than previously suspected… their onslaught of stellar creation beginning some 12 billion years ago. This time frame places the Universe at just under 2 billion years old and the star formation explosion occurring some billion years sooner than astronomers assumed. The ALMA observations included two galaxies – the “most distant of their kind ever seen” – that contained an additional revelation. Not only did their distance break astronomical records, but water molecules have been detected within them.

However, two galaxies aren’t the only score for ALMA. The research team took on 26 galaxies at wavelengths of around three millimetres. The extreme sensitivity of this cutting edge technology utilizes the measurement of light wavelengths – wavelengths produced by the galaxy’s gas molecules and stretched by the expansion of the Universe. By carefully measuring the “stretch”, astronomers are able to gauge the amount of time the light has taken to reach us and refine its point in time.

“ALMA’s sensitivity and wide wavelength range mean we could make our measurements in just a few minutes per galaxy – about one hundred times faster than before,” said Axel Weiss (Max-Planck-Institut für Radioastronomie in Bonn, Germany), who led the work to measure the distances to the galaxies. “Previously, a measurement like this would have been a laborious process of combining data from both visible-light and radio telescopes.”

For the most part, ALMA’s observations would be sufficient to determine the distance, but the team also included ALMA’s data with the Atacama Pathfinder Experiment (APEX) and ESO’s Very Large Telescope for a select few galaxies. At the present time, astronomers are only employing a small segment of ALMA’s capabilities – just 16 of the 66 massive antennae – and focusing on brighter galaxies. When ALMA is fully functional, it will be able to zero in on even fainter targets. However, the researchers weren’t about to miss any opportunities and utilized gravitational lensing to aid in their findings.

This montage combines data from ALMA with images from the NASA/ESA Hubble Space Telescope, for five distant galaxies. The ALMA images, represented in red, show the distant, background galaxies, being distorted by the gravitational lens effect produced by the galaxies in the foreground, depicted in the Hubble data in blue. The background galaxies appear warped into rings of light known as Einstein rings, which encircle the foreground galaxies. Credit:ALMA (ESO/NRAO/NAOJ), J. Vieira et al.

“These beautiful pictures from ALMA show the background galaxies warped into multiple arcs of light known as Einstein rings, which encircle the foreground galaxies,” said Yashar Hezaveh (McGill University, Montreal, Canada), who led the study of the gravitational lensing. “We are using the massive amounts of dark matter surrounding galaxies half-way across the Universe as cosmic telescopes to make even more distant galaxies appear bigger and brighter.”

Just how bright is bright? According to the news release, the analysis of the distortion has shown that a portion of these far-flung, star-forming galaxies could be as bright as 40 trillion Suns… then magnified up to 22 times more through the aid of gravitational lensing.

“Only a few gravitationally lensed galaxies have been found before at these submillimetre wavelengths, but now SPT and ALMA have uncovered dozens of them.” said Carlos De Breuck (ESO), a member of the team. “This kind of science was previously done mostly at visible-light wavelengths with the Hubble Space Telescope, but our results show that ALMA is a very powerful new player in the field.”

“This is an great example of astronomers from around the world collaborating to make an amazing discovery with a state-of-the-art facility,” said team member Daniel Marrone (University of Arizona, USA). “This is just the beginning for ALMA and for the study of these starburst galaxies. Our next step is to study these objects in greater detail and figure out exactly how and why they are forming stars at such prodigious rates.”

Bring the house lights back up, please. As ALMA peers ever further into the past, maybe one day we’ll catch our own selves… looking back.

October 10, 2012December 23, 2015 by John Williams

Dying Star Blows Surprising Spiral Bubble

Using the Atacama Large Millimeter/submillimeter Array, or ALMA, astronomers found an unexpected spiral structure surrounding the red giant star R Sculptoris shown here in this visualization. Credit: ALMA (ESO/NAOJ/NRAO)

Sometimes what we can’t see is just as surprising as what lies directly in front of us. This especially holds true in a new finding from the astronomers using the Atacama Large Millimeter/sumbillimeter Array, or ALMA, in Chile. A surprising and strange spiral structure surrounding the old star R Sculptoris is likely being created by an unseen companion, say astronomers.

The team using ALMA, the most powerful millimeter/submillimeter telescope in the world, mapped the spiral structure in three-dimensions. The astronomers say this is the first time a spiral of material, with a surrounding shell, has been observed. They report their findings in the journal Nature this week.

“We’ve seen shells around this kind of star before,” says lead author Matthias Maercker of the European Southern Observatory and Argelander Institute for Astronomy, University of Bonn, Germany in a press release. “But this is the first time we’ve ever seen a spiral of material coming out from a star, together with a surrounding shell.”

Scientists, using the NASA/ESA Hubble Space Telescope found a similar spiral, but without a surrounding shell, while observing the star LL Pegasi. Unlike the new ALMA observations, however, the astronomers could not create a three-dimensional map of the structure. Hubble observations saw the dust while ALMA detected the molecular emission.

ALMA detects the warm glow of carbon monoxide molecules in the far infrared through the multimeter wavelengths allowing astronomers to map the gas emissions surrounding the star in high-resolution. The team believes the strangely shaped bubble of material was probably created by an invisible companion star orbiting the red giant.

As stars like our Sun reach the ends of their lives, they become red giants. Swollen and cool, the stars begin a short-lived helium burning phase. During this time, the stars slough off large amounts of their mass in a dense stellar wind forming an expanding glowing shell around the stellar core. The pulses occur about every 10,000 to 50,000 years and last just a few hundred years. New observations of R Sculptoris show a pulse event rocked the star about 1,800 years ago and lasted for about 200 years. Computer simulations following the evolution of a binary system fit the new ALMA observations, according to the astronomers.

“It’s a real challenge to describe theoretically all the observed details coming from ALMA,” says co-author Shazrene Mohamed, of Argelander Institute for Astronomy in Bonn, Germany and South African Astronomical Observatory. “But our computer models show that we really are on the right track. ALMA is giving us new insight into what’s happening in these stars and what might happen to the Sun in a few billion years from now.”

A wide field view of the red giant variable star R Sculptoris. Credit: ESO/Digitized Sky Survey 2. Acknowledgement: Davide De Martin

R Sculptoris is considered by astronomers to be an asymptotic giant branch, or AGB, star. With masses between 0.8 and 8 solar masses, they are cool red giants with a tiny central core of carbon and oxygen surrounded by a burning shell of helium and hydrogen burning. Eventually, our Sun will evolve into an AGB star. The glowing shell is made up of gas and dust, material that will be used for making future stars with their retinue of planets and moons and even the building blocks of life.

“In the near future, observations of stars like R Sculptoris with ALMA will help us to understand how the elements we are made up of reached places like the Earth. They also give us a hint of what our own star’s far future might be like,” says Maercker.

This new video shows a series of slices through the data, each taken at a slightly different frequency. These reveal the shell around the star, appearing as a circular ring, that seems to gets bigger and then smaller, as well as a clear spiral structure in the inner material that it best seen about half-way through the video sequence.

Source: European Southern Observatory

Small image caption: What appears to be a thin spiral pattern winding away from a star is shown in this remarkable picture from the Advanced Camera for Surveys on the NASA/ESA Hubble Space Telescope shows one of the most perfect geometrical forms created in space. It captures the formation of an unusual pre-planetary nebula, known as IRAS 23166+1655, around the star LL Pegasi (also known as AFGL 3068) in the constellation of Pegasus (the Winged Horse). Credit: NASA/ESA Hubble

June 22, 2012December 23, 2015 by Nancy Atkinson

Early “Elemental” Galaxy Found 12.4 Billion Light Years Away

This is definitely a story about a galaxy long ago and far away. An international team of researchers using the Atacama Large Millimeter/submillimeter Array (ALMA) has observed a “submillimeter galaxy” located about 12.4 billion light-years away. Their observations have revealed that the elemental composition of this galaxy in the early universe, at only 1.3 billion years after the Big Bang, was already close to the current elemental composition of the Universe. This means that intense star formation was taking place at that early point in the Universe’s history.

A submillimeter galaxy is a type of galaxy which has intense star formation activity and is covered by large amounts of dust. Since dust blocks observations in visible light, using ALMA’s millimeter wavelength capabilities can penetrate and see though dust clouds. In addition, ALMA also has extraordinary sensitivity, which is capable of catching even extremely faint radio signals. This is one of the most distant galaxies ALMA has ever observed.

The team was able to examine the chemical composition of the galaxy, called LESS J0332, and detected an emission line that contained nitrogen. To do this, they compared the brightness ratio of the observed emission lines from nitrogen and carbon with theoretical calculations. Their results showed that the elemental composition of LESS J0332, especially the abundance of nitrogen, is significantly different from that of the Universe immediately after the Big Bang – which consisted of almost only hydrogen and helium — but was much more similar to that of our Sun today, where a variety of elements exist abundantly.

It took 12.4 billion years for the emission lines from LESS J0332 to reach us, which means that the team was able to observe the galaxy located in the young universe at 1.3 billion years after the Big Bang.

“Submillimeter galaxies are thought to be relatively massive galaxies in the growth phase. Our research, revealing that LESS J0332 already has an elemental composition similar to the sun, shows us that the chemical evolution of these massive galaxies occurred rapidly made in the early universe, that is to say, in the early universe active star formation occurred for a short period of time,” said Tohru Nagao from Kyoto University, co-author of the paper.

The observations were made with ALMA, even though construction is not yet completed; only 18 antennas were used in this observation, while ALMA will be equipped with 66 antennas when completed.

This research was published in the “Letters” section of the journal, “Astronomy & Astrophysics.”

Lead image caption: Artist impression of the submillimeter galaxy LESS J0332 observed the ALMA at the 5000-meter altitude plateau. [Credit: NAOJ]

Source: ALMA