Star Formation Archives

August 29, 2014December 23, 2015 by Shannon Hall

Radio Telescopes Resolve Pleiades Distance Debate

An optical image of the Pleiades. Credit: NOAO / AURA / NSF

Fall will soon be at our doorstep. But before the leaves change colors and the smell of pumpkin fills our coffee shops, the Pleiades star cluster will mark the new season with its earlier presence in the night sky.

The delicate grouping of blue stars has been a prominent sight since antiquity. But in recent years, the cluster has also been the subject of an intense debate, marking a controversy that has troubled astronomers for more than a decade.

Now, a new measurement argues that the distance to the Pleiades star cluster measured by ESA’s Hipparcos satellite is decidedly wrong and that previous measurements from ground-based telescopes had it right all along.

The Pleiades star cluster is a perfect laboratory to study stellar evolution. Born from the same cloud of gas, all stars exhibit nearly identical ages and compositions, but vary in their mass. Accurate models, however, depend greatly on distance. So it’s critical that astronomers know the cluster’s distance precisely.

A well pinned down distance is also a perfect stepping stone in the cosmic distance ladder. In other words, accurate distances to the Pleiades will help produce accurate distances to the farthest galaxies.

With parallax technique, astronomers observe object at opposite ends of Earth's orbit around the Sun to precisely measure its distance. CREDIT: Alexandra Angelich, NRAO/AUI/NSF. — With the parallax technique, astronomers observe object at opposite ends of Earth’s orbit around the Sun to precisely measure its distance. Credit: Alexandra Angelich, NRAO / AUI / NSF

But accurately measuring the vast distances in space is tricky. A star’s trigonometric parallax — its tiny apparent shift against background stars caused by our moving vantage point — tells its distance more truly than any other method.

Originally the consensus was that the Pleiades are about 435 light-years from Earth. However, ESA’s Hipparcos satellite, launched in 1989 to precisely measure the positions and distances of thousands of stars using parallax, produced a distance measurement of only about 392 light-years, with an error of less than 1%.

“That may not seem like a huge difference, but, in order to fit the physical characteristics of the Pleiades stars, it challenged our general understanding of how stars form and evolve,” said lead author Carl Melis, of the University of California, San Diego, in a press release. “To fit the Hipparcos distance measurement, some astronomers even suggested that some type of new and unknown physics had to be at work in such young stars.”

If the cluster really was 10% closer than everyone had thought, then the stars must be intrinsically dimmer than stellar models suggested. A debate ensued as to whether the spacecraft or the models were at fault.

To solve the discrepancy, Melis and his colleagues used a new technique known as very-long-baseline radio interferometry. By linking distant telescopes together, astronomers generate a virtual telescope, with a data-gathering surface as large as the distances between the telescopes.

The network included the Very Long Baseline Array (a system of 10 radio telescopes ranging from Hawaii to the Virgin Islands), the Green Bank Telescope in West Virginia, the William E. Gordon Telescope at the Arecibo Observatory in Puerto Rico, and the Effelsberg Radio Telescope in Germany.

“Using these telescopes working together, we had the equivalent of a telescope the size of the Earth,” said Amy Miouduszewski, of the National Radio Astronomy Observatory (NRAO). “That gave us the ability to make extremely accurate position measurements — the equivalent of measuring the thickness of a quarter in Los Angeles as seen from New York.”

After a year and a half of observations, the team determined a distance of 444.0 light-years to within 1% — matching the results from previous ground-based observations and not the Hipparcos satellite.

“The question now is what happened to Hipparcos?” Melis said.

The spacecraft measured the position of roughly 120,000 nearby stars and — in principle — calculated distances that were far more precise than possible with ground-based telescopes. If this result holds up, astronomers will grapple with why the Hipparcos observations misjudged the distances so badly.

ESA’s long-awaited Gaia observatory, which launched on Dec. 19, 2013, will use similar technology to measure the distances of about one billion stars. Although it’s now ready to begin its science mission, the mission team will have to take special care, utilizing the work of ground-based radio telescopes in order to ensure their measurements are accurate.

The findings have been published in the Aug. 29 issue of Science and is available online.

August 27, 2014December 23, 2015 by Shannon Hall

Fingerprint From a First-Generation Star?

SDSS001820.5-093939.2 (seen in white) is a small, second-generation star bearing the chemical imprint of one of the universe's first stars. It shines at an apparent magnitude of 15.8, just south of the celestial equator in the constellation Cetus. Credit: SDSS / NAO

The young universe was composed of a pristine mix of hydrogen, helium, and a tiny trace of lithium. But after hundreds of millions of years, it began to cool and giant clouds of the primordial elements collapsed to form the first stars.

The first “Population III” stars were extremely massive and bright, synthesizing the first batches of heavy elements, and erupting as supernovae after relatively short lifetimes of just a few million years. This cycle of star birth and death has steadily produced and dispersed more heavy elements throughout cosmic history.

Astronomers haven’t spotted any of the first stars still shining today. But now, a team using the 8.2-meter Subaru Telescope has discovered an ancient low-mass star that likely formed from the elements produced in the supernova explosion of a very massive first generation star.

Pop III stars with masses exceeding 100 times that of the Sun would have died in a peculiar explosion that theorists call a pair-instability supernova.

Like its lower-energy comrade, a pair-instability supernova occurs when a massive star no longer produces enough energy to counteract the inward pull of gravity. But with so much mass, the star’s core is squeezed to such a high temperature and pressure that runaway nuclear reactions power a devastating explosion. The whole star is obliterated and no compact remnant, such as a black hole or neutron star, is left behind.

Astronomers have seen hints of these rare events before. But now, Wako Aoiki from the National Astronomical Observatory of Japan and colleagues have approached the search in a different way, by finding a star that bears the chemical fingerprints of these ancient explosions.

The elements we see lacing a star’s surface provide a key to understanding the supernova that preceded the star’s birth. And the star, dubbed SDSS001820.5-093939.2, exhibits a peculiar set of chemical abundance ratios. It has high levels of heavy elements, such as nickel, calcium, and iron, but low levels of light elements, such as carbon, magnesium and cobalt.

Note that the star is still metal poor in the grand scheme of things. Its iron abundance is 1/100 of the solar level. But compared with most metal-poor stars, where the iron abundance can be 1/100,000 or less of the solar level, the star is metal rich.

The chemical abundance ratios (with respect to iron) of SDSS J0018-0939 (red circles) compared with model prediction for explosions of very-massive stars. The black line indicates the model of a pair-instability supernova by a star with 300 solar masses, whereas the blue line shows the model of an explosion caused by a core-collapse of a star with 1000 solar masses. The abundance ratios of sodium (Na) and aluminum (Al), which are not well-reproduced by these models, might be produced during the evolution of stars before the explosion, but that is not included in the current model. (Credit: NAOJ)

These odd fingerprints suggest the star formed from material seeded by the death of a very massive Pop III star. In fact, the chemical composition of the star matches the elements that pair-instability supernovae are predicted to create.

The team notes that this is the only star of about 500 in the same low-metallicity range that has this peculiar makeup. It is — at the moment — our only window into the early universe and the first generation of stars.

The paper was published Aug. 22 in Science and is available online.

August 14, 2014December 23, 2015 by Elizabeth Howell

Diamond Pinpricks: Gorgeous Shot Of Star Group That Once Baffled Astronomers

A Hubble Space Telecope picture of globular cluster IC 4499. The new observations showed that it is about 12 billion years old, contrary to previous observations showing a puzzling young age. Credit: European Space Agency and NASA

Is this group of stars belonging to one generation, or more? That’s one of the things that was puzzling astronomers for decades, particularly when they were trying to pin down the age of IC 4499 — the globular cluster you see in this new picture from the Hubble Space Telescope.

While astronomers now know the stars are from a single generation that are about 12 billion years old (see this paper from three years ago), for about 15 years before that at least one paper said IC 4499 was three billion to four billion years younger than that.

“It has long been believed that all the stars within a globular cluster form at the about same time, a property which can be used to determine the cluster’s age,” stated information from the European Space Agency reposted on NASA’s website.

“For more massive globulars however, detailed observations have shown that this is not entirely true — there is evidence that they instead consist of multiple populations of stars born at different times.”

IC 4499 is somewhere in between these extremes, but only has a single generation of stars — its gravity wasn’t quite enough to pull in neighboring gas and dust to create more. Goes to show you how important it is to re-examine the results in science.

Source: NASA and the European Space Agency

July 22, 2014December 23, 2015 by Elizabeth Howell

Cosmic Fireworks: A Supernova Feast And Google+ Hangout For Chandra’s 15th Anniversary

A collection of images from the Chandra X-Ray Observatory marking its 15th anniversary in space. Top, from left: the crab Nebula, supernova remnant G292.0+1.8 and the Crab Nebula. At bottom, supernova remnant 3C58. Credit: NASA/CXC/SAO

It’s well past the Fourth of July, but you can still easily find fireworks in the sky if you look around. The Chandra X-Ray Observatory has been doing just that for the past 15 years, revealing what the universe looks like in these longer wavelengths that are invisible to human eyes.

Just in time for the birthday, NASA released four pictures that Chandra took of supernova (star explosion) remnants it has observed over the years. The pictures stand as a symbol of what the telescope has shown us so far.

“Chandra changed the way we do astronomy. It showed that precision observation of the X-rays from cosmic sources is critical to understanding what is going on,” stated Paul Hertz, NASA’s Astrophysics Division director, in a press release. “We’re fortunate we’ve had 15 years – so far – to use Chandra to advance our understanding of stars, galaxies, black holes, dark energy, and the origin of the elements necessary for life.”

The telescope launched into space in 1999 aboard the space shuttle and currently works at an altitude as high as 86,500 miles (139,000 miles). It is named after Indian-American astrophysicist Subrahmanyan Chandrasekhar; the name “Chandra” also means “moon” or “luminous” in Sanskrit.

And there’s more to come. You can learn more about Chandra’s greatest discoveries and its future in this Google+ Hangout, which will start at 3 p.m. EDT (7 p.m. EDT) at this link.

July 10, 2014December 23, 2015 by Bob King

Merging Giant Galaxies Sport ‘Blue Bling’ in New Hubble Pic

In this new Hubble image shows two galaxies (yellow, center) from the cluster SDSS J1531+3414 have been found to be merging into one and a "chain" of young stellar super-clusters are seen winding around the galaxies'?? nuclei. The galaxies are surrounded by an egg-shaped blue ring caused by the immense gravity of the cluster bending light from other galaxies beyond it. Credit: NASA/ESA/Grant Tremblay

On a summer night, high above our heads, where the Northern Crown and Herdsman meet, a titanic new galaxy is being born 4.5 billion light years away. You and I can’t see it, but astronomers using the Hubble Space Telescope released photographs today showing the merger of two enormous elliptical galaxies into a future heavyweight adorned with a dazzling string of super-sized star clusters.

The two giants, each about 330,000 light years across or more than three times the size of the Milky Way, are members of a large cluster of galaxies called SDSS J1531+3414. They’ve strayed into each other’s paths and are now helpless against the attractive force of gravity which pulls them ever closer.

A few examples of merging galaxies. NASA, ESA, the Hubble Heritage Team (STScI/AURA)-ESA/Hubble Collaboration and A. Evans (University of Virginia, Charlottesville/NRAO/Stony Brook University), K. Noll (STScI), and J. Westphal (Caltech)

Galactic mergers are violent events that strip gas, dust and stars away from the galaxies involved and can alter their appearances dramatically, forming large gaseous tails, glowing rings, and warped galactic disks. Stars on the other hand, like so many pinpoints in relatively empty space, pass by one another and rarely collide.

Elliptical galaxies get their name from their oval and spheroidal shapes. They lack the spiral arms, rich reserves of dust and gas and pizza-like flatness that give spiral galaxies like Andromeda and the Milky Way their multi-faceted character. Ellipticals, although incredibly rich in stars and globular clusters, generally appear featureless.

The differences between elliptical and spiral galaxies is easy to see. M87 at left and M74, both photographed with the Hubble Space Telescope. Credit: NASA/ESA — The differences between elliptical and spiral galaxies is easy to see. M87 at left and M74, both photographed with the Hubble Space Telescope. What look like stars around M87 are really globular star clusters. Credit: NASA/ESA

But these two monster ellipticals appear to be different. Unlike their gas-starved brothers and sisters, they’re rich enough in the stuff needed to induce star formation. Take a look at that string of blue blobs stretching across the center – astronomers call it a great example of ‘beads on a string’ star formation. The knotted rope of gaseous filaments with bright patches of new star clusters stems from the same physics which causes rain or water from a faucet to fall in droplets instead of streams. In the case of water, surface tension makes water ‘snap’ into individual droplets; with clouds of galactic gas, gravity is the great congealer.

Close up of the two elliptical galaxies undergoing a merger. The blue blobs are giant star clusters forming from gas colliding and collapsing into stars during the merger. Click for the scientific paper on the topic. Credit: NASA/ESA/Grant Tremblay — Close up of the two elliptical galaxies undergoing a merger. The blue blobs are giant star clusters forming from gas colliding and collapsing into stars during the merger. Click to read the scientific paper on the topic. Credit: NASA/ESA/Grant Tremblay

Nineteen compact clumps of young stars make up the length of this ‘string’, woven together with narrow filaments of hydrogen gas. The star formation spans 100,000 light years, about the size of our galaxy, the Milky Way. Astronomers still aren’t sure if the gas comes directly from the galaxies or has condensed like rain from X-ray-hot halos of gas surrounding both giants.

The blue arcs framing the merger have to do with the galaxy cluster’s enormous gravity, which warps the fabric of space like a lens, bending and focusing the light of more distant background galaxies into curvy strands of blue light. Each represents a highly distorted image of a real object.

Simulation of the Milky Way-Andromeda collision 4 billion years from now

Four billion years from now, Milky Way residents will experience a merger of our own when the Andromeda Galaxy, which has been heading our direction at 300,000 mph for millions of years, arrives on our doorstep. After a few do-si-dos the two galaxies will swallow one another up to form a much larger whirling dervish that some have already dubbed ‘Milkomeda’. Come that day, perhaps our combined galaxies will don a string a blue pearls too.

June 26, 2014December 23, 2015 by David Dickinson

The Making of the Pillars of Creation

It’s one of the most iconic images of the modern Space Age. In 1995, the Hubble Space Telescope team released an image of towering columns of gas and dust that contained newborn stars in the midst of formation. Dubbed the “Pillars of Creation,” these light-years long tendrils captivated the public imagination and now grace everything from screensavers to coffee mugs. This is a cosmic portrait of our possible past, and the essence of the universe giving birth to new stars and worlds in action.

Now, a study out on Thursday from the 2014 National Astronomy Meeting of the Royal Astronomical Society has shed new light on just how these pillars may have formed. The announcement comes out of Cardiff University, where astronomer Scott Balfour has run computer simulations that closely model the evolution and the outcome of what’s been observed by the Hubble Space Telescope.

The ‘Pillars’ lie in the Eagle Nebula, also known as Messier 16 (M16), which is situated in the constellation Serpens about 7,000 light years distant. The pillars themselves have formed as intense radiation from young massive stars just beginning to shine erode and sculpt the immense columns.

The location of Messier 16 and the Pillars of Creation in the night sky. Credit: Stellarium.

But as is often the case in early stellar evolution, having massive siblings nearby is bad news for fledgling stars. Such large stars are of the O-type variety, and are more than 16 times as massive as our own Sun. Alnitak in Orion’s belt and the stars of the Trapezium in the Orion Nebula are examples of large O-type stars that can be found in the night sky. But such stars have a “burn fast and die young” credo when it comes to their take on nuclear fusion, spending mere millions of years along the Main Sequence of the Hertzsprung Russell diagram before promptly going supernova. Contrast this with a main sequence life expectancy of 10 billion years for our Sun, and life spans measured in the trillions of years — longer than the current age of the universe — for tiny red dwarf stars. The larger a star you are, the shorter your life span.

Such O-Type stars also have surface temperatures at a scorching 30,000 degrees Celsius, contrasted with a relatively ‘chilly’ 5,500 degree Celsius surface temperature for our Sun.

This also results in a prodigious output in energetic ultraviolet radiation by O-type stars, along with a blustery solar wind. This carves out massive bubbles in a typical stellar nursery, and while it may be bad news for planets and stars attempting to form nearby any such tempestuous stars, this wind can also compress and energize colder regions of gas and dust farther out and serve to trigger another round of star formation. Ironically, such stars are thus “cradle robbers” when it comes to potential stellar and planetary formation AND promoters of new star birth.

In his study, Scott looked at the way gas and dust would form in a typical proto-solar nebula over the span of 1.6 million years. Running the simulation over the span of several weeks, the model started with a massive O-type star that formed out of an initial collapsing smooth cloud of gas.

That’s not bad, a simulation where 1 week equals a few hundred million years…

As expected, said massive star did indeed carve out a spherical bubble given the initial conditions. But Scott also found something special: the interactions of the stellar winds with the local gas was much more complex than anticipated, with three basic results: either the bubble continued to expand unimpeded, the front would expand, contract slightly and then become a stationary barrier, or finally, it would expand and then eventually collapse back in on itself back to the source.

The study was notable because it’s only in the second circumstance that the situation is favorable for a new round of star formation that is seen in the Pillars of Creation.

“If I’m right, it means that O-type and other massive stars play a much more complex role than we previously thought in nursing a new generation of stellar siblings to life,” Scott said in a recent press release. “The model neatly produces exactly the same kind of structures seen by astronomers in the classic 1995 image, vindicating the idea that giant O-type stars have a major effect in sculpting their surroundings.”

Such visions as the Pillars of Creation give us a snapshot of a specific stage in stellar evolution and give us a chance to study what we may have looked like, just over four billion years ago. And as simulations such as those announced in this week’s study become more refined, we’ll be able to use them as a predictor and offer a prognosis for a prospective stellar nebula and gain further insight into the secret early lives of stars.

June 13, 2014December 23, 2015 by Elizabeth Howell

Hubble Hubba: Stars Are Being Born Around A Black Hole In Galaxy’s Center

Hubble Space Telescope picture of galaxy NGC 3081. Credit: ESA/Hubble & NASA; acknowledgement: R. Buta (University of Alabama)

Let’s just casually look at this image of a galaxy 86 million light-years away from us. In the center of this incredible image is a bright loop that you can see surrounding the heart of the galaxy. That is where stars are being born, say the scientists behind this new Hubble Space Telescope image.

“Compared to other spiral galaxies, it looks a little different,” NASA stated. “The galaxy’s barred spiral center is surrounded by a bright loop known as a resonance ring. This ring is full of bright clusters and bursts of new star formation, and frames the supermassive black hole thought to be lurking within NGC 3081 — which glows brightly as it hungrily gobbles up in-falling material.”

A “resonance ring” refers to an area where gravity causes gas to stick around in certain areas, and can be the result of a ring (like you see in NGC 3081) or close-by objects with a lot of gravity. Scientists added that NGC 3081, which is in the constellation Hydra or the Sea Serpent, is just one of many examples of barred galaxies with this type of resonance.

By the way, this image is a combination of several types of light: optical, infrared and ultraviolet.

Source: NASA Goddard Space Flight Center

June 11, 2014December 23, 2015 by Dan Majaess

Too WISE to be Fooled by Dust: Over 300 New Star Clusters Discovered

A new study by Brazilian astronomers details the discoveries of some 300 new star clusters using the WISE space telescope (credit NASA/JPL-Caltech/UCLA).

Brazilian astronomers have discovered some 300+ star clusters that were largely overlooked owing to sizable obscuration by dust. The astronomers, from the Universidade Federal do Rio Grande do Sul, used data obtained by NASA’s WISE (Wide-Field Infrared Survey Explorer) space telescope to detect the clusters.

“WISE is a powerful tool to probe … young clusters throughout the Galaxy”, remarked the group. The clusters discovered were previously overlooked because the constituent stars are deeply embedded in their parent molecular cloud, and are encompassed by dust. Stars and star clusters can emerge from such environments.

The group added that, “The present catalog of new clusters will certainly become a major source for future studies of star cluster formation.” Indeed, WISE is well-suited to identify new stars and their host clusters because infrared radiation is less sensitive to dust obscuration. The infrared part of the electromagnetic spectrum is sampled by WISE.

An optical (DSS) and infrared (WISE) image of the same field. A cluster of young stars is not apparent in the optical (left) image owing to obscuration by dust. However, a young star cluster is apparent in the right image because the dust reradiates the absorbed radiation in the infrared regime. The new study highlights the discovery of numerous star clusters discovered using infrared (WISE) data (image credit: DSS/NASA and assembly by D. Majaess). — An optical (DSS) and infrared (WISE) image of the same field. A cluster of young stars is not apparent in the optical (left) image owing to obscuration by dust. However, a young star cluster is readily apparent in the right image because dust obscuration is significantly less at infrared wavelengths. A new study by a team of astronomers highlights the discovery of numerous star clusters using WISE data (image credit: DSS/NASA/IPAC and assembly by D. Majaess).

Historically, new star clusters were often identified while inspecting photographic plates imaged at (or near) visible wavelengths (i.e., the same wavelengths sampled by the eye). Young embedded clusters were consequently under-sampled since the amount of obscuration by dust is wavelength dependent. As indicated in the figure above, the infrared observations penetrate the dust by comparison to optical observations.

The latest generation of infrared survey telescopes (e.g., Spitzer and WISE) are thus excellent instruments for detecting clusters embedded in their parent cloud, or hidden from detection because of dust lying along the sight-line. The team notes that, “The Galaxy appears to contain 100000 open clusters, but only some 2000 have established astrophysical parameters.” It is hoped that continued investigations using WISE and Spitzer will help astronomers minimize that gap.

The discoveries are described in a new study by D. Camargo, E. Bica, and C. Bonatto that is entitled “New Glactic embedded cluster and candidates from a WISE survey“. The study has been accepted for publication, and will appear in a forthcoming issue of the journal New Astronomy. For more information on Galactic star clusters see the Dias et al. catalog, the WEBDA catalog, or the Star Clusters Young & Old Newsletter. Thanks to K. MacLeod for the title suggestion.

The WISE (Wide-field Infrared Survey Explorer) space telescope was used to discover numerous new star clusters (image credit: NASA)(. — The WISE (Wide-field Infrared Survey Explorer) space telescope was used to discover numerous star clusters (image credit: NASA).

June 4, 2014December 23, 2015 by Jason Major

Astronomers Find Evidence of a Strange Type of Star

Illustration of the red supergiant Betelgeuse, as seen from a fictional orbiting world. © Digital Drew.

One has never been spotted for sure in the wild jungle of strange stellar objects out there, but astronomers now think they have finally found a theoretical cosmic curiosity: a Thorne-Zytkow Object, or TZO, hiding in the neighboring Small Magellanic Cloud. With the outward appearance of garden-variety red supergiants, TZOs are actually two stars in one: a binary pair where a super-dense neutron star has been absorbed into its less dense supergiant parter, and from within it operates its exotic elemental forge.

First theorized in 1975 by physicist Kip Thorne and astronomer Anna Zytkow, TZOs have proven notoriously difficult to find in real life because of their similarity to red supergiants, like the well-known Betelgeuse at the shoulder of Orion. It’s only through detailed spectroscopy that the particular chemical signatures of a TZO can be identified.

Infrared portrait of the Small Magellanic Cloud, made by NASA's Spitzer Space Telescope — Portrait of the Small Magellanic Cloud, made by NASA’s Spitzer Space Telescope

Observations of the red supergiant HV 2112 in the Small Magellanic Cloud*, a dwarf galaxy located a mere 200,000 light-years away, have revealed these signatures — unusually high concentrations of heavy elements like molybdenum, rubidium, and lithium.

While it’s true that these elements are created inside stars — we are all star-stuff, like Carl Sagan said — they aren’t found in quantity within the atmospheres of lone supergiants. Only by absorbing a much hotter star — such as a neutron star left over from the explosive death of a more massive partner — is the production of such elements presumed to be possible.

“Studying these objects is exciting because it represents a completely new model of how stellar interiors can work,”said Emily Levesque, team leader from the University of Colorado Boulder and lead author on the paper. “In these interiors we also have a new way of producing heavy elements in our universe.”

Definitive detection of a TZO would provide direct evidence for a completely new model of stellar interiors, as well as confirm a theoretically predicted fate for massive star binary systems and the existence of nucleosynthesis environments that offer a new channel for heavy-element and lithium production in our universe.
– E.M. Levesque et al., Discovery of a Thorne-Zytkow object candidate in the Small Magellanic Cloud

One of the original proposers of TZOs, Dr. Anna Zytkow, is glad to see her work resulting in new discoveries.

“I am extremely happy that observational confirmation of our theoretical prediction has started to emerge,” Zytkow said. “Since Kip Thorne and I proposed our models of stars with neutron cores, people were not able to disprove our work. If theory is sound, experimental confirmation shows up sooner or later. So it was a matter of identification of a promising group of stars, getting telescope time and proceeding with the project.”

The findings were first announced in January at the 223rd meeting of the American Astronomical Society. The paper has now been accepted for publication in the Monthly Notices of the Royal Astronomical Society Letters, and is co-authored by Philip Massey, of Lowell Observatory in Flagstaff, Arizona; Anna Zytkow of the University of Cambridge in the U.K.; and Nidia Morrell of the Carnegie Observatories in La Serena, Chile. Read the team’s paper here.

Source: University of Colorado, Boulder. Illustration by ‘Digital Drew.’
__________________________
*In the paper the team notes that it’s not yet confirmed that HV 2112 is part of the SMC and could be associated with our own galaxy. If so it would rule out it being a TZO, but would still require an explanation of its observed spectra.

May 22, 2014December 23, 2015 by Elizabeth Howell

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

"Cosmic clumps" seen in NASA's Spitzer Space Telescope throw the deepest shadows scientists have ever seen. Credit: NASA/JPL-Caltech/University of Zurich

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