Hubble, Spitzer Collaborate for Stunning Panorama of Galactic Center


Two of the biggest space telescopes have combined forces to create a HUGE panorama of the center of the Milky Way galaxy. This sweeping, composite color panorama is the sharpest infrared picture ever made of the Galactic core. Revealed in the image are a new population of massive stars and new details of complex structures in the hot gas and dust swirling around, created by solar winds and supernova explosions. The image shows an area about 300 light-years across. Click here for options in seeing this image in small, medium or super-sized extra large resolution! Click here for a stunning movie showing the location and more detail of this image in visible light. Astronomers at the American Astronomical Society meeting pointed out the actual galactic center is in the large white region near the lower right side of the image. If you need something to keep you occupied for awhile, try counting the number of stars in this image!

More about this image…

This image provides insight into how massive stars form and influence their environment in the often violent nuclear regions of other galaxies. This view combines the sharp imaging of the Hubble Space Telescope’s Near Infrared Camera and Multi-Object Spectrometer (NICMOS) with color imagery from a previous Spitzer Space Telescope survey done with its Infrared Astronomy Camera (IRAC). The Galactic core is obscured in visible light by intervening dust clouds, but infrared light penetrates the dust. The spatial resolution of NICMOS corresponds to 0.025 light-years at the distance of the galactic core of 26,000 light-years. Hubble reveals details in objects as small as 20 times the size of our own solar system. The NICMOS images were taken between February 22 and June 5, 2008.

Source: HubbleSite

Powerful Rivers of Gas Imaged Around Star-Forming Swan Nebula


The turbulent and dynamic Swan Nebula (M17) has been imaged by NASA’s Spitzer Space Telescope, producing the clearest view yet of the star-forming region. Within the twisted cloud of gas and dust, violent stellar winds constantly blast the medium, generating flows around stars, creating vast bow shocks. A few massive stars in the centre of M17 are the main source of the relentless stellar “rivers” of gas, immersing smaller stars in the the flow, acting like stationary rocks on a riverbed…

This new observing campaign by Spitzer (an infrared telescope that has been in Earth orbit since 2003, and is expected to be operational until 2009), has imaged the M17 nebula with unprecedented clarity. Although it is a known fact that stellar winds inside star-forming regions generate dynamic features such as bow shocks, you cannot put a price on actually seeing these structures in an infrared image (pictured top). From analysis of these Spitzer results, Matt Povich of the University of Wisconsin has published a paper describing these new findings in the December 10th issue of the Astrophysical Journal.

The stars are like rocks in a rushing river,” said Povich when describing the scene. “Powerful winds from the most massive stars at the center of the cloud produce a large flow of expanding gas. This gas then piles up with dust in front of winds from other massive stars that are pushing back against the flow.”

The Swan Nebula can be found in the constellation of Sagittarius, some 6000 light years away. It is a very active star-forming cloud where powerful stellar winds are eroding away the dust, clearing the region. Driving this mechanism are a group of massive stars exceeding 40 times the mass, and 100,000–1 million times the brightness, of the Sun. The stellar winds bullying smaller stars and blowing away the clouds of dust in the middle of the nebula have flow velocities exceeding 7.2 million km/hr (4.5 million mi/hr). To put this in perspective, the fast solar wind (the fastest component of our Sun’s two-component solar wind) reaches a maximum velocity of 2.8 million km/hr (1.7 million mi/hr); the stellar winds inside the Swan are 2.5 times more powerful.

So what’s the result of this powerful stellar wind engine in M17? A very obvious cavity is created inside the nebula, a process thought to spark the birth of new stars. This stellar nursery is fuelled by the compression of the edge of the cavity, producing bow shocks around anything that is relatively stationary (i.e. other stars). The direction of the bow shocks provide information about the direction of the stellar winds.

Povich studies another star forming region called RCW 49 in addition to M17, picking out the glowing gases generated inside the shock fronts maintained by the flow of stellar flows. Spitzer turns out to be the perfect tool to peer deep into nebulae, picking out the infrared emissions from bow shocks, mapping them.

The gas being lit up in these star-forming regions looks very wispy and fragile, but looks can be deceiving,” co-author Robert Benjamin added. “These bow shocks serve as a reminder that stars aren’t born in quiet nurseries but in violent regions buffeted by winds more powerful than anything we see on Earth.”

Further observation campaigns like this one will ultimately help astronomers understand how stellar systems, like our Solar System, form out of the violence of stellar birth.

Source: NASA,

An Inside Look at Comet Holmes

The astronomy world buzzed in the Fall of 2007 when Comet Holmes – a normally humdrum, run-of-the-mill comet — unexpectedly flared and erupted. Its coma of gas and dust expanded away from the comet, extending to a volume larger than the Sun. Professional and amateur astronomers around the world turned their telescopes toward the spectacular event. Everyone wanted to know why the comet had suddenly exploded. The Hubble Space Telescope observed the comet, but provided few clues. And now, observations taken of the comet after the explosion by NASA’s Spitzer Space Telescope deepen the mystery, showing oddly behaving streamers in the shell of dust surrounding the nucleus of the comet. The data also offer a rare look at the material liberated from within the nucleus. “The data we got from Spitzer do not look like anything we typically see when looking at comets,” said Bill Reach of NASA’s Spitzer Science Center at Caltech.

Every six years, comet 17P/Holmes speeds away from Jupiter and heads inward toward the sun, traveling the same route typically without incident. However, twice in the last 116 years, in November 1892 and October 2007, comet Holmes exploded as it approached the asteroid belt, and brightened a millionfold overnight.

In an attempt to understand these odd occurrences, astronomers pointed NASA’s Spitzer Space Telescope at the comet in November 2007 and March 2008. By using Spitzer’s infrared spectrograph instrument, Reach and his colleagues were able to gain valuable insights into the composition of Holmes’ solid interior. Like a prism spreading visible-light into a rainbow, the spectrograph breaks up infrared light from the comet into its component parts, revealing the fingerprints of various chemicals.

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

In November of 2007, Reach noticed a lot of fine silicate dust, or crystallized grains smaller than sand, like crushed gems. He noted that this particular observation revealed materials similar to those seen around other comets where grains have been treated violently, including NASA’s Deep Impact mission, which smashed a projectile into comet Tempel 1; NASA’s Stardust mission, which swept particles from comet Wild 2 into a collector at 13,000 miles per hour (21,000 kilometers per hour), and the outburst of comet Hale-Bopp in 1995.

“Comet dust is very sensitive, meaning that the grains are very easily destroyed, said Reach. “We think the fine silicates are produced in these violent events by the destruction of larger particles originating inside the comet nucleus.”

When Spitzer observed the same portion of the comet again in March 2008, the fine-grained silicate dust was gone and only larger particles were present. “The March observation tells us that there is a very small window for studying composition of comet dust after a violent event like comet Holmes’ outburst,” said Reach.

Comet Holmes not only has unusual dusty components, it also does not look like a typical comet. According to Jeremie Vaubaillon, a colleague of Reach’s at Caltech, pictures snapped from the ground shortly after the outburst revealed streamers in the shell of dust surrounding the comet. Scientists suspect they were produced after the explosion by fragments escaping the comet’s nucleus.

In November 2007, the streamers pointed away from the sun, which seemed natural because scientists believed that radiation from the sun was pushing these fragments straight back. However, when Spitzer imaged the same streamers in March 2008, they were surprised to find them still pointing in the same direction as five months before, even though the comet had moved and sunlight was arriving from a different location. “We have never seen anything like this in a comet before. The extended shape still needs to be fully understood,” said Vaubaillon.

He notes that the shell surrounding the comet also acts peculiarly. The shape of the shell did not change as expected from November 2007 to March 2008. Vaubaillon said this is because the dust grains seen in March 2008 are relatively large, approximately one millimeter in size, and thus harder to move.

“If the shell was comprised of smaller dust grains, it would have changed as the orientation of the sun changes with time,” said Vaubaillon. “This Spitzer image is very unique. No other telescope has seen comet Holmes in this much detail, five months after the explosion.”

“Like people, all comets are a little different. We’ve been studying comets for hundreds of years — 116 years in the case of comet Holmes — but still do not really understand them,” said Reach. “However, with the Spitzer observations and data from other telescopes, we are getting closer.”

Source: Spitzer Press Release

Star Blasting Water From Its Surroundings


The Spitzer Space Telescope has spied water in a cloud of gas and dust around a nascent star. That’s interesting in itself, but even more remarkable, the water is being blasted apart by the young star’s laser-like jets. Spitzer’s spectrometer was used to get a better look at these jets and analyze the jet’s molecules. To the astronomers’ surprise, Spitzer picked up the signature of rapidly spinning fragments of water molecules, called hydroxyl, or OH. “This is a truly unique observation that will provide important information about the chemistry occurring in planet-forming regions, and may give us insights into the chemical reactions that made water and even life possible in our own solar system,” said Achim Tappe, of the Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass.

A young star forms out of a thick, rotating cloud of gas and dust. Like the two ends of a spinning top, powerful jets of gas emerge from the top and bottom of the dusty cloud. As the cloud shrinks more and more under its own gravity, its star eventually ignites and the remaining dust and gas flatten into a pancake-like disk, from which planets will later form. By the time the star ignites and stops accumulating material from its cloud, the jets will have died out.

Tappe and his colleagues used Spitzer’s infrared eyes to cut through the dust surrounding the star, called HH 211-mm, to analyze the jets. The astronomers were surprised to see water molecules in the data. But the results showed the hydroxyl molecules have absorbed so much energy (through a process called excitation) that they are rotating around with energies equivalent to 28,000 Kelvin (27,700 degrees Celsius). This far exceeds normal expectations for gas streaming out of a stellar jet. Water, which is abbreviated H2O, is made up of two hydrogen atoms and one oxygen; hydroxyl, or OH, contains one oxygen and one hydrogen atom.

The results reveal that the jet is ramming its head into a wall of material, vaporizing ice right off the dust grains it normally coats. The jet is hitting the material so fast and hard that a shock wave is also being produced.

“The shock from colliding atoms and molecules generates ultraviolet radiation, which will break up water molecules, leaving extremely hot hydroxyl molecules,” said Tappe.

Tappe said this same process of ice being vaporized off dust occurs in our own solar system, when the sun vaporizes ice in approaching comets. In addition, the water that now coats our world is thought to have come from icy comets that vaporized as they rained down on a young Earth. This discovery provides a better understanding of how water — an essential ingredient for life as we know it — is processed in emerging solar systems.

Source: JPL

Spitzer Takes Family Portrait of Stars Amid Another “Celestal Geode”


A new image from NASA’s Spitzer Space Telescope reveals generations of stars amid a cavity carved from a colorful cosmic cloud. The striking infrared picture shows a region, called W5, which is similar to N44F, or the “Celestial Geode” that was discussed in a Universe Today article last week. The gas cavity, which looks similar to a geode-like cavity found in some rocks, is carved by the stellar wind and intense ultraviolet radiation from hot stars. W5 is studded with stars of various ages, and provides new evidence that massive stars – through their brute winds and radiation – can trigger the birth of new stars.

The image was unveiled today at the Griffith Observatory in Los Angeles as part of Spitzer’s five-year anniversary celebration. Spitzer launched on August 25, 2003, from Cape Canaveral Air Force Station, Fla. A high-resolution version of the image is available here. It shows a family history full of life and death. But are the deaths of some stars responsible for the birth of new stars?

“Triggered star formation continues to be very hard to prove,” said Xavier Koenig of the Harvard Smithsonian Center for Astrophysics in Cambridge, Mass. “But our preliminary analysis shows that the phenomenon can explain the multiple generations of stars seen in the W5 region.”

The most massive stars in the universe form out of thick clouds of gas and dust. The stars are so massive, ranging from 15 to about 60 times the mass of the Sun, that some of their material slides off in the form of winds. The scorching-hot stars also blaze with intense radiation. Over time, both the wind and radiation blast away surrounding cloud material, carving out expanding cavities.

Astronomers have long suspected that the carving of these cavities causes gas to compress into successive generations of new stars. As the cavities grow, it is believed that more and more stars arise along the cavities’ expanding rims. The result is a radial “family tree” of stars, with the oldest in the middle of the cavity and younger and younger stars farther out.

The astronomer who last week explained the N44F image, Dr. You-Hua Chu from the University of Illinois, said along the walls of the cavity there are dust pillars sticking out and young stars are being formed at the tips of these pillars. Similar features are seen in the new Spitzer image of W5, where younger stars (seen as pink or white in the image) are embedded in the elephant-trunk-like pillars as well, and also beyond the cavity rim. The most massive stars (seen as blue dots) are at the center of two hollow cavities.

With Spitzer’s infrared vision, Koenig and his colleagues peered through the dusty regions of W5 to get a better look at the stars’ various stages of evolution and test the triggered star formation theory. The results from their studies show that stars within the W5 cavities are older than stars at the rims, and even older than stars farther out past the rim. This ladder-like separation of ages provides some of the best evidence yet that massive stars do, in fact, give rise to younger generations.

“Our first look at this region suggests we are looking at one or two generations of stars that were triggered by the massive stars,” said co-author Lori Allen of the Harvard-Smithsonian Center for Astrophysics. “We plan to follow up with even more detailed measurements of the stars’ ages to see if there is a distinct time gap between the stars just inside and outside the rim.”

Another version of the image, taken with Spitzer's Infrared Array Camera.
Another version of the image, taken with Spitzer's Infrared Array Camera.

Millions of years from now, the massive stars in W5 will die in tremendous explosions. When they do, they will destroy some of the young nearby stars – the same stars they might have triggered into being.

W5 spans an area of sky equivalent to four full moons and is about 6,500 light-years away in the constellation Cassiopeia. The Spitzer picture was taken over a period of 24 hours. The color red shows heated dust that pervades the region’s cavities. Green highlights the dense clouds, and white knotty areas are where the youngest of stars are forming. The blue dots are older stars in the region, as well as other stars in the background and foreground.

A paper on the findings will appear in the December 1, 2008, issue of the Astrophysical Journal.

Source: Harvard Smithsonian Center for Astrophysics

No Life Possible at Edges of the Pinwheel Galaxy

Another beautiful image from the Spitzer Space Telescope; in this case, it’s Messier 101, more commonly known as the Pinwheel Galaxy. But the pretty red highlights at the edges of the galaxy are bad news for anyone looking for evidence of life. “If you were going look for life in Messier 101, you would not want to look at its edges,” said Karl Gordon of the Space Telescope Science Institute. “The organics can’t survive in these regions, most likely because of high amounts of harsh radiation.” The red color highlights a zone where organic molecules called polycyclic aromatic hydrocarbons (PAHs), which are present throughout most of the galaxy, suddenly disappear.

PAHs are dusty, carbon-containing molecules found in star nurseries. They’re also found on Earth in barbeque pits, exhaust pipes and anywhere combustion reactions take place. Scientists believe this space dust has the potential to be converted into the stuff of life.

The Pinwheel galaxy is located about 27 million light-years away in the constellation Ursa Major. It has one of the highest known gradients of metals (elements heavier than helium) of all nearby galaxies in our universe. In other words, its concentrations of metals are highest at its center, and decline rapidly with distance from the center. This is because stars, which produce metals, are squeezed more tightly into the galaxy’s central quarters.

Gordon’s team also wanted to learn more about the gradient of the PAHs. Using Spitzer’s Infrared Array Camera and the Infrared Spectograph to carefully analyze the spectra of the PAHs, astronomers can more precisely identify the PAH features, and even deduce information about their chemistry and temperature. The astronomers found that, like the metals, the polycyclic aromatic hydrocarbons decrease in concentration toward the outer portion of the galaxy. But, unlike the metals, these organic molecules quickly drop off and are no longer detected at the very outer rim.

“There’s a threshold at the rim of this galaxy, where the organic material is getting destroyed,” said Gordon.

The findings also provide a better understanding of the conditions under which the very first stars and galaxies arose. In the early universe, there were not a lot of metals or PAHs around. The outskirt of the Pinwheel galaxy therefore serves as a close-up example of what the environment might look like in a distant galaxy.

In this image, infrared light with a wavelength of 3.6 microns is colored blue; 8-micron light is green; and 24-micron light is red. All three of Spitzer instruments were used in the study: the infrared array camera, the multiband imaging photometer and the infrared spectrograph.

Original News Source: JPL

Baby Boomer Galaxy Found

This galaxy, Zw II 96 (about 500 million light-years away) resembles the Baby Boom galaxy which lies about 12.3 billion light-years away and appears in images as only a smudge.

A group of telescopes got together recently to check out a little hanky-panky going on in a galaxy in a very remote part of the universe. The Hubble and Spitzer Space Telescopes, Japan’s Subaru Telescope, the James Clerk Maxwell and the Keck Telescopes, all on Mauna Kea in Hawaii, and the Very Large Array in New Mexico pooled their various optical, infrared, submillimeter and radio capabilities to see why a distant galaxy appears to be conceiving stars at a tremendously fast rate. This galaxy, which has now been dubbed the “Baby Boom” galaxy, is giving birth to about 4,000 stars per year. In comparison, our own Milky Way galaxy turns out an average of just 10 stars per year. These telescopes weren’t just playing the part of a Peeping Tom; astronomers want to find out more about this incredibly fertile galaxy.

“This galaxy is undergoing a major baby boom, producing most of its stars all at once,” said Peter Capak of NASA’s Spitzer Science Center at the California Institute of Technology, Pasadena. “If our human population was produced in a similar boom, then almost all of the people alive today would be the same age.”

The discovery goes against the most common theory of galaxy formation, the Hierarchical Model. According to the theory galaxies slowly bulk up their stars over time, and not in one big burst as “Baby Boom” appears to be doing.

The Baby Boom galaxy, which belongs to a class of galaxies called starbursts, is the new record holder for the brightest starburst galaxy in the very distant universe, with brightness being a measure of its extreme star-formation rate. It was discovered and characterized using a suite of telescopes operating at different wavelengths. NASA’s Hubble Space Telescope and Japan’s Subaru Telescope, atop Mauna Kea in Hawaii, first spotted the galaxy in visible-light images, where it appeared as an inconspicuous smudge due to is great distance.

It wasn’t until Spitzer and the James Clerk Maxwell Telescope, also on Mauna Kea in Hawaii, observed the galaxy at infrared and submillimeter wavelengths, respectively, that the galaxy stood out as the brightest of the bunch. This is because it has a huge number of youthful stars. When stars are born, they shine with a lot of ultraviolet light and produce a lot of dust. The dust absorbs the ultraviolet light but, like a car sitting in the sun, it warms up and re-emits light at infrared and submillimeter wavelengths, making the galaxy unusually bright to Spitzer and the James Clerk Maxwell Telescope.

To learn more about this galaxy’s unique youthful glow, Capak and his team followed up with a number of telescopes. They used optical measurements from Keck to determine the exact distance to the galaxy — a whopping12.3 billion light-years. That’s looking back to a time when the universe was 1.3 billion years old (the universe is approximately 13.7 billion years old today).

The astronomers made measurements at radio wavelengths with the National Science Foundation’s Very Large Array in New Mexico. Together with Spitzer and James Clerk Maxwell data, these observations allowed the astronomers to calculate a star-forming rate of about 1,000 to 4,000 stars per year. At that rate, the galaxy needs only 50 million years, not very long on cosmic timescales, to grow into a galaxy equivalent to the most massive ones we see today.

“Before now, we had only seen galaxies form stars like this in the teenaged universe, but this galaxy is forming when the universe was only a child,” said Capak. “The question now is whether the majority of the very most massive galaxies form very early in the universe like the Baby Boom galaxy, or whether this is an exceptional case. Answering this question will help us determine to what degree the Hierarchical Model of galaxy formation still holds true.”

“The incredible star-formation activity we have observed suggests that we may be witnessing, for the first time, the formation of one of the most massive elliptical galaxies in the universe,” said co-author Nick Scoville of Caltech.

Original News Source: JPL

Mysterious Omega Centauri Dazzling in Infrared: New Spitzer Observations

By combining ground-based optical observations with space-borne infrared images from Spitzer, an incredible new view of mysterious Omega Centauri has been revealed. Astronomers have had a hard time identifying what type of galaxy Omega Centauri actually is, so any new information on the cluster of millions of stars is needed. By combining observations in different wavelengths, stars of different ages are highlighted, possibly aiding our understanding about the origins of Omega Centauri and answer the question: Why is this galaxy so strange?

As discussed in an article last week, Omega Centauri is of particular interest to astrophysicists. Over the years this strange collection of stars has been classified as a single star (by Ptolemy), a nebula (by Halley in 1677) and a globular cluster (by Herschel in the 1830’s). Now it is believed that this dwarf galaxy may be a survivor of an ancient collision with the Milky Way which stripped away its outermost stars. This is why it may look like a globular cluster now, but doesn’t have globular cluster characteristics. For a start Omega Centauri is too big (ten times bigger than the largest globular clusters) and it contains stars of many generations (globular clusters usually contain one generation). Recent observations also show a very fast rotating galactic core, revealing the presence of an intermediate-size black hole… the missing link connecting stellar black holes with supermassive black holes. Exciting stuff.

Omega Centauri in optical and infrared wavelengths (NASA/JPL-Caltech/ NOAO/AURA/NSF)

Putting the scientific implications to one side for now, I can’t help but stare at this stunning view of this interesting cluster of star systems. I’m used to monochromatic images of space with some false-colour thrown in for good measure; this image seems to be different. Very quickly we are able to gain an insight to the dispersion of star generations, just by looking at the image. A quick glance shows the majority of young stars are clustered toward the middle (the blue stars), older red giants located around the outside of the galaxy (the red/yellow stars).

Detail of Omega Centauri stars - highlighting a Spitzer red giant and some Blanco young stars (NASA/JPL-Caltech/ NOAO/AURA/NSF)

According to the NASA news release, where green and red dots overlap, yellow dots appear. These are NASA Spitzer Space Telescope stars observed in infrared. We know that these emissions come from old, large and dusty stars, the red giants. The blue dots are younger stars, much like our Sun, as observed in optical and near-infrared wavelengths by the National Science Foundation’s Blanco 4-meter telescope at Cerro Tololo Inter-American Observatory in Chile. I’ve included a little section from the main image with the two types of star ringed and annotated (pictured).

These new Spitzer observations show very little dust around any of the dimmest red giants and the space between the stars also does not seem to contain much dust (as interstellar dust would glow infrared radiation as nearby stars heat it). Astronomers have concluded that any dust within the cluster is quickly destroyed or lost from the galaxy.

Source: NASA

Time Traveling With Spitzer

While time travel is seemingly impossible, we can actually look back in time with our telescopes to learn about the conditions of our universe in times past. The Spitzer Space Telescope has found some very dim and distant galaxies located at the edge of our universe that have never been seen before. Approximately 12.5 billion light-years away from Earth, we’re seeing these galaxies as when our universe was just one billion years old. With Spitzer’s infrared capability, astronomers have been able to take infrared portraits and even “weigh” many of these early galaxies. “Understanding the mass and chemical makeup of the universe’s first galaxies and then taking snapshots of galaxies at different ages, gives us a better idea of how gas, dust and metals– the material that went into making our Sun, solar system, and Earth –has changed throughout the Universe’s history,” said Spitzer scientist Dr. Ranga Ram Chary.

Unlike the galaxies of today, Chary says that galaxies living in the one billion year old universe were much more pristine. They were comprised primarily of hydrogen and helium gas and contained less than 10% of the heavier elements we see in the local Universe today, and even on Earth. Astronomers have found these distant galaxies were cosmic “lightweights”, or not very massive compared to mature galaxies we see nearby.

“A few billion years after the big bang, 90 percent of the stars being born were occurring in these types of faint galaxies. By identifying this population, we hope to gain insights into the environments where the universe’s first stars formed,” said Chary.

To find these faint galaxies, astronomers followed the lingering afterglow of gamma ray bursts back to their sources. Astronomers believe gamma ray bursts appear when a very massive star dies and becomes a black hole.

The afterglow occurs when energetic electrons spiral around magnetic fields, and release light. In its explosive death, material shooting out of the massive star smashes into surrounding gas. This violent collision heats nearby gas and energizes its electrons.

Once coordinates of the faint galaxies were determined, Chary’s team then used Spitzer’s supersensitive infrared array camera to snap a picture of the faint galaxy. The amount of light from the galaxies allowed Chary to find the mass of the galaxies.

Original News Source: Spitzer Space Telescope Press Release

Could AA Tauri Hold the Biochemical Key to Extra-Terrestrial Life?

NASA’s Spitzer Space Telescope has measured huge quantities of water and organic compounds surrounding the star AA Tauri, 450 light years from Earth. AA Tauri is a young star, only a million years old, not too dissimilar to our Sun when it was a baby. What makes AA Tauri even more special is that it appears to have the “spectral fingerprint” for a system that could allow life to form. Finding a star system similar to our own, with organic compounds was always bound to cause excitement, but finding a star so close to us provides a fantastic opportunity to study AA Tauri. This will, in turn, help us understand the evolution of our own solar system and how life is able to form…

AA Tauri is slowly evolving. Gas and dust surrounds the star and recent observations suggest there are abundant organic chemicals (the ones responsible for binding together and creating amino acids). Although NASA’s announcement isn’t claiming that ET is out there (you can sit back into your seats), it is significant that a star should have all the building blocks for life as we know it laid out for the spectrometer on board Spitzer to observe.

The basic organic chemicals in question are possibly located within the “Goldilocks Zone” for planetary/life development from AA Tauri. Although AA Tauri is young, the surrounding flat disk of planetary-forming materials should eventually coalesce to form rocky bodies such as planets, asteroids and possibly gas giants (along the lines of “failed star” Jupiter). The abundance of organic chemicals and water will add to the intrigue surrounding the star.
A comparison between a model and observations of AA Tauri - water is present around the baby star (credit: NASA/JPL/CalTech/J. Carr/NRL)
These observations were collected by NASA’s Spitzer Space Telescope which is able to probe deep into the chemical structure of stars hundreds of parsecs from Earth. John Carr (Naval Research Laboratory, Washington) and Joan Najita (National Optical Astronomy Observatory, Tucson, Ariz.) are developing a new technique, applying Spitzer’s infrared spectrograph. The spectrograph is able to read the chemical composition of the dust contained within a protoplanetary disk. The team has been able to push Spitzer to a new level of precision by analysing the chemical composition of dust particles rather than the gas surrounding the star.

Most of the material within the disks is gas, but until now it has been difficult to study the gas composition in the regions where planets should form. Much more attention has been given to the solid dust particles, which are easier to observe.” – John Carr of the Naval Research Laboratory, Washington.

So far abundances of hydrogen cyanide, acetylene, carbon dioxide and water vapour have been discovered, allowing scientists to see whether these organic chemicals are enriched or lost during the violent period of planetary formation. Observations such as these highly accurate measurements allow us a chance to glimpse back in time to see what our protoplanetary solar system may have looked like, clearly a very exciting time for the quest to find the origins of life in our galaxy.

Source: NASA/JPL