These Ultra-Black ‘Cosmic Clumps’ Will Give Birth To Powerful Stars

When gas and dust squeeze tightly enough together in space, no light can get through and the place is black as pitch. But this dusty cloud seen about 16,000 light-years away from us will eventually generate new stars, with the darkest parts creating powerful O-type stars — a star-type poorly known to scientists.

“The map of the structure of the cloud and its dense cores we have made in this study reveals a lot of fine details about the massive star and star cluster formation process,” stated Michael Butler, a postdoctoral researcher at the University of Zurich in Switzerland who led the study.

The new study, which included observations from NASA’s Spitzer Space Telescope, examined the shadows these clumps cast and concluded this cloud is about 7,000 times more massive than the sun, and about 50 light-years in diameter. Because Spitzer examines the universe in infrared light, this allows it to peer through dusty areas that are difficult or impossible to see in visual light, allowing Spitzer to examine different astronomical phenomena.

Artist's concept of NASA's Spitzer Space Telescope surrounded by examples of exoplanets it has looked at. Credit: NASA/JPL-Caltech
Artist’s concept of NASA’s Spitzer Space Telescope surrounded by examples of exoplanets it has looked at. Credit: NASA/JPL-Caltech

Looking at clouds such as this one are expected to shed more light (so to speak) on how O-type stars are created. This stellar type is at least 16 times as massive as the sun (but can be much more) and is known for its wind and powerful radiation, that clean out the neighborhood of any dust or gas that could have formed other planets or stars.

Once these stars reach the end of their short lives, they explode as supernovas and also create heavier elements that are found in rocky planets and in the case of Earth (as far as we know), living beings. Researchers are still unclear on how the stars are able to pick up mass that is so much more the mass of our sun without breaking apart.

A mission extension for Spitzer was not approved after a NASA Senior Review made public last week, but officials were told to submit a revised budget for consideration in 2016.

You can read more about the study, which was published earlier this year, in Astrophysical Journal Letters.

Source: Jet Propulsion Laboratory

Supernova Sweeps Away Rubbish In New Composite Image

Shining 24,000 light-years from Earth is an expanding leftover of a supernova that is doing a great cleanup job in its neighborhood. As this new composite image from NASA reveals, G352.7-0.1 (G352 for short) is more efficient than expected, picking up debris equivalent to about 45 times the mass of the Sun.

“A recent study suggests that, surprisingly, the X-ray emission in G352 is dominated by the hotter (about 30 million degrees Celsius) debris from the explosion, rather than cooler (about 2 million degrees) emission from surrounding material that has been swept up by the expanding shock wave,” the Chandra X-Ray Observatory’s website stated.

“This is curious because astronomers estimate that G352 exploded about 2,200 years ago, and supernova remnants of this age usually produce X-rays that are dominated by swept-up material. Scientists are still trying to come up with an explanation for this behavior.”

More information about G352 is available in the Astrophysical Journal and also in preprint version on Arxiv.

Source: Chandra X-Ray Telescope

360 Degrees of Milky Way at Your Fingertips

Touring the Milky Way’s a blast with this brand new 360-degree interactive panorama. More than 2 million infrared photos taken by NASA’s Spitzer Space Telescope were jigsawed into a 20-gigapixel click-and-zoom mosaic that takes the viewer from tangled nebulae to stellar jets to blast bubbles around supergiant stars.  

Magnetic loops carry gas and dust above disks of planet-forming material circling stars, as shown in this artist's conception. These loops give off extra heat, which NASA's Spitzer Space Telescope detects as infrared light. The colors in this illustration show what an alien observer with eyes sensitive to both visible light and infrared wavelengths might see. Credit: NASA/JPL-Caltech/R. Hurt (IPAC)
Magnetic loops carry gas and dust above disks of planet-forming material circling stars, as shown in this artist’s conception. These loops give off extra heat, which NASA’s Spitzer Space Telescope detects as infrared light. The colors in this illustration show what an alien observer with eyes sensitive to both visible light and infrared wavelengths might see. Credit: NASA/JPL-Caltech/R. Hurt (IPAC)

The new composite, using infrared images taken over the past decade, was compiled by a team led by UW-Madison astronomer Barbara Whitney and unveiled at a TEDactive conference in Vancouver, Canada Thursday. Unlike visual light, infrared penetrates the ubiquitous dust concentrated in the galactic plane to reveal structures otherwise obscured.


Catching a GLIMPSE of the Milky Way in this short video presentation

“For the first time, we can actually measure the large-scale structure of the galaxy using stars rather than gas,” explained Edward Churchwell, UW-Madison professor of astronomy and team co-leader. “We’ve established beyond the shadow of a doubt that our galaxy has a large bar structure that extends halfway out to the sun’s orbit. We know more about where the Milky Way’s spiral arms are.”

Named GLIMPSE360 (Galactic Legacy Mid-Plane Survey Extraordinaire project), the deep infrared survey captures only about 3% of the sky, but because it focuses on the plane of the Milky Way, where stars are most highly concentrated, it shows more than half of all the galaxy’s 300 billion suns.

The Milky Way is a spiral galaxy with several prominent arms containing stellar nurseries swathed in  pink clouds of hydrogen gas. The sun is shown near the bottom in the Orion Spur. Credit: NASA
The Milky Way is a spiral galaxy with several prominent arms containing stellar nurseries swathed in pink clouds of hydrogen gas. The sun is shown near the bottom in the Orion Spur. Credit: NASA

Using your imagination to hover high above the galactic plane, you’d see the Milky Way is a flat spiral galaxy sporting a stubby bar of stars crossing its central bulge. The solar system occupies a tiny niche in a minor spiral arm called the Orion Spur two-thirds of the way from the center to the edge.  At 100,000 light years across, the Milky Way is vast beyond comprehension and yet it’s only one of an estimated 100 billion galaxies in the observable universe.

Bubbles of gas and sites of star formation are seen in this close up from a region in the constellation Sagittarius. Credit:
Bubbles of gas and sites of star formation are seen in this close up in a region in the constellation Sagittarius. Credit:

While you and I sit back and marvel at all the stellar and nebular eye candy, the Spitzer images are helping astronomers determine where the edge of the galaxy lies and location of the spiral arms. GLIMPSE images have already revealed the Milky Way to be larger than previously thought and shot through with bubbles of expanding gas and dust blown by giant stars.

Spitzer can see faint stars in the “backcountry” of our galaxy — the outer, darker regions that went largely unexplored before.

Barbara Whitney, co-leader of the GLIMPSE360 team
Barbara Whitney, co-leader of the GLIMPSE360 team

“There are a whole lot more lower-mass stars seen now with Spitzer on a large scale, allowing for a grand study,” said Whitney. “Spitzer is sensitive enough to pick these up and light up the entire ‘countryside’ with star formation.”

The new 360-degree view will also help NASA’s upcoming James Webb Space Telescope target the most interesting sites of star-formation, where it will make even more detailed infrared observations.

When you play around with the interactive mosaic,  you’ll notice a few artifacts here and there among the images. Minor stuff. What took some getting used to was  how strikingly different familiar nebulae appeared when viewed in infrared instead of visual light. The panorama is also available on the Aladin viewing platform which offers shortcuts to regions of interest.

Neil deGrasse Tyson, astrophysicist and host of the new Cosmos TV series, gave the third line of our “cosmic address” as the Milky Way after ‘Earth’ and ‘Solar System’. After a few minutes with GLIMPSE360 you’ll  better appreciate the depth and breadth of our galactic home.

Runaway Star Shocks the Galaxy!

That might seem like a sensational headline worthy of a supermarket tabloid but, taken in context, it’s exactly what’s happening here!

The bright blue star at the center of this image is a B-type supergiant named Kappa Cassiopeiae, 4,000 light-years away. As stars in our galaxy go it’s pretty big — over 57 million kilometers wide, about 41 times the radius of the Sun. But its size isn’t what makes K Cas stand out — it’s the infrared-bright bow shock it’s creating as it speeds past its stellar neighbors at a breakneck 1,100 kilometers per second.

K Cas is what’s called a runway star. It’s traveling very fast in relation to the stars around it, possibly due to the supernova explosion of a previous nearby stellar neighbor or companion, or perhaps kicked into high gear during a close encounter with a massive object like a black hole.

As it speeds through the galaxy it creates a curved bow shock in front of it, like water rising up in front of the bow of a ship. This is the ionized glow of interstellar material compressed and heated by K Cas’ stellar wind. Although it looks like it surrounds the star pretty closely in the image above, the glowing shockwave is actually about 4 light-years out from K Cas… slightly less than the distance from the Sun to Proxima Centauri.

The bow shock of Zeta Ophiuchi, another runaway star observed by Spitzer (NASA/JPL-Caltech)
The bow shock of Zeta Ophiuchi, another runaway star observed by Spitzer (NASA/JPL-Caltech)

Although K Cas is visible to the naked eye, its bow shock isn’t. It’s only made apparent in infrared wavelengths, which NASA’s Spitzer Space Telescope is specifically designed to detect. Some other runaway stars have brighter bow shocks — like Zeta Ophiuchi at right — which can be seen in optical wavelengths (as long as they’re not obscured by dust, which Zeta Oph is.)

Related: Surprise! IBEX Finds No Bow ‘Shock’ Outside our Solar System

The bright wisps seen crossing K Cas’ bow shock may be magnetic filaments that run throughout the galaxy, made visible through interaction with the ionized gas. In fact bow shocks are of particular interest to astronomers precisely because they help reveal otherwise invisible features and allow deeper investigation into the chemical composition of stars and the regions of the galaxy they are traveling through. Like a speeding car on a dark country road, runaway stars’ bow shocks are — to scientists — like high-beam headlamps lighting up the space ahead.

Runaway stars are not to be confused with rogue stars, which, although also feel the need for speed, have been flung completely out of their home galaxies.

Source: NASA

Space Telescopes Look Back 13.2 Billion Years and See Surprisingly Luminous Galaxies

What was the Universe like more than 13 billion years ago, just 500 million years after the big bang? New data from the Hubble and Spitzer space telescopes reveal some surprisingly bright galaxies that are about 10 to 20 times more luminous than anything seen previously in that epoch.

Garth Illingworth from the University of California, Santa Cruz said the discovery of these four bright galaxies came from combining the power of both telescopes, but these galaxies lie right at the limit of the telescopes’ capabilities.

“We’re actually reaching back 13.2 billion years through the life of the Universe — that’s 96% of the life of the Universe that we are looking back at these galaxies,” said Illingworth, speaking at the American Astronomical Society meeting in Washington D.C. this week. “That’s an astonishing undertaking and an astonishing accomplishment that Hubble and Spitzer have achieved.”

Detail of the Hubble and Spitzer observations of a galaxy from the early Universe. Credit: NASA, ESA, G. Illingworth (University of California, Santa Cruz), P. Oesch (University of California, Santa Cruz; Yale University), R. Bouwens and I. Labbé (Leiden University), and the Science Team.
Detail of the Hubble and Spitzer observations of a galaxy from the early Universe. Credit: NASA, ESA, G. Illingworth (University of California, Santa Cruz), P. Oesch (University of California, Santa Cruz; Yale University), R. Bouwens and I. Labbé (Leiden University), and the Science Team.

Illingworth said the typical galaxy candidate from that far back in time is very faint and hard to see. But these new galaxies are about 15-20 % brighter than what astronomers have seen before at redshift 10.

The tiny are bright because they are bursting with star formation activity. The brightest one is forming stars approximately 50 times faster than the Milky Way does today. Although these fledgling galaxies are only one-twentieth the size of the Milky Way, they probably contain around a billion stars crammed together.

Astronomers think these bright, young galaxies grew exceptionally fast because of interactions and mergers of smaller infant galaxies that started forming stars even earlier in the Universe. Since the ancient time billions of years ago when the light that we now see started its long journey to us, they have probably kept growing to become similar to the largest modern galaxies. Many of the stars of these infant galaxies likely live on today in the centers of giant elliptical galaxies, much larger even than our own Milky Way.

Slide from Garth Illingworth's presentation at the 223rd American Astronomical Society meeting, describing the discovery of bright galaxies from early in the Universe. Credit: Garth Illingworth.
Slide from Garth Illingworth’s presentation at the 223rd American Astronomical Society meeting, describing the discovery of bright galaxies from early in the Universe. Credit: Garth Illingworth.

Illingworth said this era appears to be a timeframe where things were changing quite rapidly. “We’ve gone back to a very interesting time when the Universe is changing,” he said.

The galaxies were first detected with Hubble, and astronomers were able to measure their star-formation rates and sizes. But using Spitzer, the scientists were also able to measure the galaxies’ masses.

“This is the first-ever measurement of the mass density of the galaxies when the Universe was at 500 million years of age,” Illingworth said. “These galaxies are about a billion times the mass of our Sun, which is massive for those times, but still only 1% the mass of the Milky Way.”

Illingworth added that the mass measurements are rough estimates because of how challenging the task was.

Illingworth and team member Ivo Labbé from Leiden University said they are looking forward to finding out more about these galaxies, particularly from future observations with the upcoming James Webb Space Telescope.

“At the same time, the extreme masses and star formation rates are really mysterious,” Labbé said, “and we are eager to confirm them with future observations on our powerful telescopes.”

You can find out more about these early galaxies — and more — at the First Galaxies website.

Further reading: HubbleSite

How Spitzer’s Focus Changed To Strange New Worlds

After 10 years in space — looking at so many galaxies and stars and other astronomy features — the Spitzer Space Telescope is being deployed for new work: searching for alien worlds.

The telescope is designed to peer in infrared light (see these examples!), the wavelength in which heat is visible. When looking at infrared light from exoplanets, Spitzer can figure out more about their atmospheric conditions. Over time, it can even detect brightness differences as the planet orbits its sun, or measure the temperature by looking at how much the brightness declines when the planet goes behind its star. Neat stuff overall.

“When Spitzer launched back in 2003, the idea that we would use it to study exoplanets was so crazy that no one considered it,” stated Sean Carey of NASA’s Spitzer Science Center, which is at the California Institute of Technology. “But now the exoplanet science work has become a cornerstone of what we do with the telescope.”

Of course, the telescope wasn’t designed to do this. But to paraphrase the movie Apollo 13, NASA was interested in what the telescope could do while it’s in space — especially because the planet-seeking Kepler space telescope has been sidelined by a reaction wheel problem. Redesigning Spitzer, in a sense, took three steps.

Classifying Galaxies
An example of Spitzer’s past work: This image from NASA’s Spitzer Space Telescope shows infrared light from the Sunflower galaxy, otherwise known as Messier 63. Spitzer’s view highlights the galaxy’s dusty spiral arms. Image credit: NASA/JPL-Caltech

Fixing the wobble: Spitzer is steady, but not so steady that it could easily pick out the small bit of light that an exoplanet emits. Engineers determined that the telescope actually wobbled regularly and would wobble for an hour. Looking into the problem further, they discovered it’s because a heater turns on to keep the telescope battery’s temperature regulated.

“The heater caused a strut between the star trackers and telescope to flex a bit, making the position of the telescope wobble compared to the stars being tracked,” NASA stated. In October 2010, NASA decided to cut the heating back to 30 minutes because the battery only needs about 50 per cent of the heat previously thought. Half the wobble and more exoplanets was more the recipe they were looking for.

The Spitzer Space Telescope.  Credit:  NASA
The Spitzer Space Telescope. Credit: NASA

Repurposing a camera: Spitzer has a pointing control reference sensor “peak-up” camera on board, which originally gathered up infrared light to funnel to a spectrometer. It also calibrated the telescope’s star-tracker pointing devices. The same principle was applied to infrared camera observations, putting stars in the center of camera pixels and allowing a better view.

Remapping a camera pixel: The scientists charted the variations in a single pixel of the camera that showed them which were the most stable areas for observations. For context, about 90% of Spitzer’s exoplanet observations are about a 1/4 of a pixel wide.

That’s pretty neat stuff considering that Spitzer’s original mission was just 2.5 years, when it had coolant on board to allow three temperature-sensitive science instruments to function. Since then, engineers have set up a passive cooling system that lets one set of infrared cameras keep working.

Source: NASA

NASA’s Great Observatories Provide a Sparkly New View of the Small Magellanic Cloud

This is just pretty! NASA’s Great Observatories — the Hubble Space Telescope, the Chandra X-Ray Observatory and the Spitzer Infrared Telescope — have combined forces to create this new image of the Small Magellanic Cloud. The SMC is one of the Milky Way’s closest galactic neighbors. Even though it is a small, or so-called dwarf galaxy, the SMC is so bright that it is visible to the unaided eye from the Southern Hemisphere and near the equator.

What did it take to create this image? Let’s take a look at the images from each of the observatories:

The Small Magellenic Cloud in X-Ray from the Chandra X-Ray Observatory. Credit: NASA.
The Small Magellenic Cloud in X-Ray from the Chandra X-Ray Observatory. Credit: NASA.
The Small Magellenic Cloud in infrared, from the Spitzer Infrared Telescope. Credit: NASA.
The Small Magellenic Cloud in infrared, from the Spitzer Infrared Telescope. Credit: NASA.
The Small Magellenic Cloud as seen in optical wavelengths from the Hubble Space Telescope. Credit: NASA.
The Small Magellenic Cloud as seen in optical wavelengths from the Hubble Space Telescope. Credit: NASA.

The various colors represent wavelengths of light across a broad spectrum. X-rays from NASA’s Chandra X-ray Observatory are shown in purple; visible-light from NASA’s Hubble Space Telescope is colored red, green and blue; and infrared observations from NASA’s Spitzer Space Telescope are also represented in red.

The three telescopes highlight different aspects of this lively stellar community. Winds and radiation from massive stars located in the central, disco-ball-like cluster of stars, called NGC 602a, have swept away surrounding material, clearing an opening in the star-forming cloud.

Find out more at this page from Chandra, and this one from JPL.

Distant Star Goes Disco

A disco inferno in space? Astronomers have been keeping an eye on an unusual star that unleashes a burst of light every 25 days, like an extremely slow pulsating disco ball. Similar pulsating bursts of light have been seen before, but this one, named LRLL 54361 is the most powerful beacon ever seen.

Using the Spitzer and Hubble space telescopes, astronomers have solved the mystery of this star. It is actually two newly formed protostars in a binary system, doing a little disco dance of their own. And as they spin around each other on the smoky dance floor (actually a dense cloud of gas and dust), a blast of radiation is unleashed each time the stars get close to each other in their orbits. The effect seen by the telescopes is enhanced by an optical illusion called a light echo.

NASA's Spitzer and Hubble space telescopes have teamed up to uncover a mysterious infant star that behaves like a police strobe light. Credit: NASA, ESA, J. Muzerolle (STScI), E. Furlan (NOAO and Caltech), K. Flaherty (University of Arizona/Steward Observatory), Z. Balog (Max Planck Institute for Astronomy), and R. Gutermuth (University of Massachusetts, Amherst).
NASA’s Spitzer and Hubble space telescopes have teamed up to uncover a mysterious infant star that behaves like a police strobe light. Credit: NASA, ESA, J. Muzerolle (STScI), E. Furlan (NOAO and Caltech), K. Flaherty (University of Arizona/Steward Observatory), Z. Balog (Max Planck Institute for Astronomy), and R. Gutermuth (University of Massachusetts, Amherst).

The unusual thing is, while astronomers have seen this phenomenon before, called pulsed accretion, usually it is found in later stages of star birth – and not in such a young system or with such intensity and regularity.
Astronomers say LRLL 54361 offers insights into the early stages of star formation when lots of gas and dust is being rapidly accreted to form a new binary star.

“This protostar has such large brightness variations with a precise period that it is very difficult to explain,” said James Muzerolle of the Space Telescope Science Institute. His paper recently was published in the journal Nature.

Discovered by NASA’s Spitzer Space Telescope, LRLL 54361 is a variable object inside the star-forming region IC 348, located 950 light-years from Earth. Data from Spitzer’s dust-piercing infrared cameras showed unusual outbursts in the brightness, occurring every 25.34 days, which is a very rare phenomenon.

Based on statistical analysis, the two stars are estimated to be no more than a few hundred thousand years old.

Astronomers used the Hubble Space Telescope to confirm the Spitzer observations and reveal the detailed stellar structure around LRLL 54361. Hubble observed two cavities above and below a dusty disk. The cavities are visible by tracing light scattered off their edges. They likely were blown out of the surrounding natal envelope of dust and gas by an outflow launched near the central stars. The disk and the envelope prevent the suspected binary star pair from being observed directly. By capturing multiple images over the course of one pulse event, the Hubble observations uncovered a spectacular movement of light away from the center of the system, the light echo optical illusion, where a sudden flash or burst of light is reflected off a source and arrives at the viewer some time after the initial flash.

A series of images taken by Hubble Space Telescope over  a month show the pulse of light moving through the nebula. The light is illuminating the material around the stars. Credit: NASA, ESA, and Z. Levay (STScI)
A series of images taken by Hubble Space Telescope over a month show the pulse of light moving through the nebula. The light is illuminating the material around the stars. Credit: NASA, ESA, and Z. Levay (STScI)

Muzerolle and his team hypothesized the pair of stars in the center of the dust cloud move around each other in a very eccentric orbit. As the stars approach each other, dust and gas are dragged from the inner edge of a surrounding disk. The material ultimately crashes onto one or both stars, which triggers a flash of light that illuminates the circumstellar dust. The system is rare because close binaries account for only a few percent of our galaxy’s stellar population. This is likely a brief, transitory phase in the birth of a star system.

Muzerolle’s team next plans to continue monitoring LRLL 54361 using other facilities including the European Space Agency’s Herschel Space Telescope. The team hopes to eventually obtain more direct measurements of the binary star and its orbit.

Read Muzerolle’s paper (pdf)

Source: HubbleSite

Clouds of Sand and Iron Swirl in a Failed Star’s Extreme Atmosphere

This artist's conception illustrates the brown dwarf named 2MASSJ22282889-431026. NASA's Hubble and Spitzer space telescopes observed the object to learn more about its turbulent atmosphere. Brown dwarfs are more massive and hotter than planets but lack the mass required to become sizzling stars. Their atmospheres can be similar to the giant planet Jupiter's. Spitzer and Hubble simultaneously observed the object as it rotated every 1.4 hours. The results suggest wind-driven, planet-size clouds. Image credit:

Artist’s concept of brown dwarf  2MASSJ22282889-431026 (NASA/JPL-Caltech)

The complex weather patterns within the atmosphere of a rapidly-rotating brown dwarf have been mapped in the highest detail ever by researchers using the infrared abilities of NASA’s Spitzer and Hubble space telescopes… talk about solar wind!

Sometimes referred to as failed stars, brown dwarfs form from condensing gas and dust like regular stars but never manage to gather enough mass to ignite full-on hydrogen fusion in their cores. As a result they more resemble enormous Jupiter-like planets, radiating low levels of heat while possessing bands of wind-driven eddies in their upper atmospheric layers.

Although brown dwarfs are by their nature very dim, and thus difficult to observe in visible wavelengths of light, their heat can be detected by Hubble and the Spitzer Space Telescope — both of which can “see” just fine in near- and far-infrared, respectively.

Led by researchers from the University of Arizona, a team of astronomers used these orbiting observatories on July 7, 2011 to measure the light curves from a brown dwarf named 2MASSJ22282889-431026 (2M2228 for short.) What they found was that while 2M2228 exhibited periodic brightening in both near- and far-infrared over the course of its speedy 1.43-hour rotation, the amount and rate of brightening varied between the different wavelengths detected by the two telescopes.

ssc2013-01a_Inline

“With Hubble and Spitzer, we were able to look at different atmospheric layers of a brown dwarf, similar to the way doctors use medical imaging techniques to study the different tissues in your body.”

– Daniel Apai, principal investigator, University of Arizona

This unexpected variance — or phase shift — most likely indicates different layers of cloud material and wind velocities surrounding 2M2228, swirling around the dwarf star in very much the same way as the stormy cloud bands seen on Jupiter or Saturn.

But while the clouds on Jupiter are made of gases like ammonia and methane, the clouds of 2M2228 are made of much more unusual stuff.

ssc2013-01b_Inline“Unlike the water clouds of Earth or the ammonia clouds of Jupiter, clouds on brown dwarfs are composed of hot grains of sand, liquid drops of iron, and other exotic compounds,” said Mark Marley, a research scientist at NASA’s Ames Research Center and co-author of the paper. “So this large atmospheric disturbance found by Spitzer and Hubble gives a new meaning to the concept of extreme weather.”

While it might seem strange to think about weather on a star, remember that brown dwarfs are much more gas planet-like than “real” stars. Although the temperatures of 1,100–1,600 ºF (600–700 ºC) found on 2M2228 might sound searingly hot, it’s downright chilly compared to even regular stars like our Sun, which has an average temperature of nearly 10,000 ºF (5,600 ºC). Different materials gather at varying layers of its atmosphere, depending on temperature and pressure, and can be penetrated by different wavelengths of infrared light — just like gas giant planets.

“What we see here is evidence for massive, organized cloud systems, perhaps akin to giant versions of the Great Red Spot on Jupiter,” said Adam Showman, a theorist at the University of Arizona involved in the research. “These out-of-sync light variations provide a fingerprint of how the brown dwarf’s weather systems stack up vertically. The data suggest regions on the brown dwarf where the weather is cloudy and rich in silicate vapor deep in the atmosphere coincide with balmier, drier conditions at higher altitudes — and vice versa.”

The team’s results were presented today, January 8, during the 221st meeting of the American Astronomical Society in Long Beach, CA.

Read more on the Spitzer site, and find the team’s paper in PDF form here.

Inset image: the anatomy of a brown dwarf’s atmosphere (NASA/JPL).

Orion Revisited: Astronomers Find New Star Cluster in Front of the Orion Nebula

The well-known star-forming region of the Orion Nebula.  Credit: Canada-France-Hawaii Telescope / Coelum (J.-C. Cuillandre & G. Anselmi)

Precise distances are difficult to gauge in space, especially within the relatively local regions of the Galaxy. Stars which appear close together in the night sky may actually be separated by many hundreds or thousands of light-years, and since there’s only a limited amount of space here on Earth with which to determine distances using parallax, astronomers have to come up with other ways to figure out how far objects are, and what exactly is in front of or “behind” what.

Recently, astronomers using the 340-megapixel MegaCam on the Canada-France-Hawaii Telescope (CFHT) observed the star-forming region of the famous Orion nebula — located only about 1,500 light-years away — and determined that two massive groupings of the nebula’s stars are actually located in front of the cluster as completely separate structures… a finding that may ultimately force astronomers to rethink how the many benchmark stars located there had formed.

Although the Orion nebula is easily visible with the naked eye (as the hazy center “star” in Orion’s three-star sword, hanging perpendicular below his belt) its true nebulous nature wasn’t identified until 1610. As a vast and active star-forming region of bright dust and gas located a mere 1,500 light-years distant, the various stars within the Orion Nebula Cluster (ONC) has given astronomers invaluable benchmarks for research on many aspects of star formation.

[Read more: Astrophoto – Orion’s Bloody Massacre]

Now, CFHT observations of the Orion nebula conducted by Dr. Hervé Bouy of the European Space Astronomy Centre (ESAC) and Centre for Astrobiology (CSIC) and Dr. João Alves of the Institut für Astronomie (University of Vienna) have shown that a massive cluster of stars known as NGC 1980 is actually in front of the nebula, and is an older group of approximately 2,000 stars that is separate from the stars found within the ONC… as well as more massive than once thought.

“It is hard to see how these new observations fit into any existing theoretical model of cluster formation, and that is exciting because it suggests we might be missing something fundamental.”

– Dr. João Alves, Institut für Astronomie, University of Vienna

In addition their observations with CFHT — which were combined with previous observations with ESA’s Herschel and XMM-Newton and NASA’s Spitzer and WISE — have led to the discovery of another smaller cluster, L1641W.

According to the team’s paper, “We find that there is a rich stellar population in front of the Orion A cloud, from B-stars to M-stars, with a distinct 1) spatial distribution; 2) luminosity function; and 3) velocity dispersion from the reddened population inside the Orion A cloud. The spatial distribution of this population peaks strongly around NGC 1980 (iota Ori) and is, in all likelihood, the extended stellar content of this poorly studied cluster.”

The findings show that what has been known as Orion Nebula Cluster is actually a combination of older and newer groups of stars, possibly calling for a “revision of most of the observables in the benchmark ONC region (e.g., ages, age spread, cluster size, mass function, disk frequency, etc.)”

[Read more: Astronomers See Stars Changing Right Before Their Eyes in Orion Nebula]

“We must untangle these two mixed populations, star by star, if we are to understand the region, and star formation in clusters, and even the early stages of planet formation,” according to co-author Dr. Hervé Bouy.

The team’s article “Orion Revisited” was published in the November 2012 Astronomy & Astrophysics journal. Read the CFHT press release here.

The Canada-France-Hawaii Telescope’s Mauna Kea summit dome in September 2009. Credit: CFHT/Jean-Charles Cuillandre

Inset image: Orion nebula seen in optical – where the molecular cloud is invisible – and infrared, which shows the cloud. Any star detected in the optical in the line of sight over the region highlighted in the right panel must therefore be located in the foreground of the molecular cloud. Credit: J. Alves & H. Bouy.