Protoplanetary Disc Around HL Tauri

This is the sharpest image ever taken by ALMA — sharper than is routinely achieved in visible light with the NASA/ESA Hubble Space Telescope. It shows the protoplanetary disc surrounding the young star HL Tauri. These new ALMA observations reveal substructures within the disc that have never been seen before and even show the possible positions of planets forming in the dark patches within the system.

Image credit: ALMA (ESO/NAOJ/NRAO)

Note: For more information, see Revolutionary ALMA Image Reveals Planetary Genesis.

Artist’s Impression of Protoplanetary Discs Around Young Stars HK Tauri A and B

This artist’s impression shows a striking pair of wildly misaligned planet-forming gas discs around both the young stars in the binary system HK Tauri. ALMA observations of this system have provided the clearest picture ever of protoplanetary discs in a double star. The new result demonstrates one possible way to explain why so many exoplanets — unlike the planets in the Solar System — came to have strange, eccentric or inclined orbits.

Illustration credit: R. Hurt (NASA/JPL-Caltech/IPAC)

Note: For more information, see ALMA Finds Double Star with Weird and Wild Planet-Forming Discs

Water's Early Journey in a Solar System

The building blocks of comets, and apparently Saturn's largest moon, Titan, formed under similar conditions in the disk of gas and dust that formed the sun.

NASA's Spitzer Space Telescope observed a fledgling solar system like the one depicted in this artist's concept, and discovered deep within it enough water vapor to fill the oceans on Earth five times. This water vapor starts out in the form of ice in a cloudy cocoon (not pictured) that surrounds the embryonic star, called NGC 1333-IRAS 4B (buried in center of image). Material from the cocoon, including ice, falls toward the center of the cloud. The ice then smacks down onto a dusty pre-planetary disk circling the stellar embryo (doughnut-shaped cloud) and vaporizes. Eventually, this water might make its way into developing planets.

Illustration credit: NASA/JPL-Caltech

Note: For more information, see Titan's Building Blocks Might Pre-date Saturn.

Dust Ring Around HR 4796A

This infrared image shows the dust ring around the nearby star HR 4796A in the southern constellation of Centaurus. It was one of the first produced by the SPHERE instrument soon after it was installed on ESO’s Very Large Telescope in May 2014. It shows not only the ring itself with great clarity, but also reveals the power of SPHERE to reduce the glare from the very bright star — the key to finding and studying exoplanets in future.

Image credit: ESO/J.-L. Beuzit et al./SPHERE Consortium

Note: For more information, see First Light for SPHERE Exoplanet Imager.

Carbon Monoxide Gas Around Beta Pictoris

This artist's concept illustrates the preferred model for explaining ALMA observations of Beta Pictoris. The new observations from ALMA now show that the disc around the star is permeated by carbon monoxide gas. The presence of carbon monoxide could indicate that the Beta Pictoris planetary system may eventually become a good habitat for life. At the outer fringes of the system, the gravitational influence of a hypothetical giant planet (bottom left) captures comets into a dense, massive swarm (right) where frequent collisions occur.

Illustration credit: NASA's Goddard Space Flight Center/F. Reddy

Note: For more information, see Crashing Comets Explain Surprise Gas Clump Around Young Star.

Herschel's 37,000 Science Observations

This animation shows the timeline of over 37,000 scientific observations made by ESA’s Herschel space observatory throughout its entire mission, condensed into less than a minute.

The animation was prepared by Pedro Gómez-Alvarez in the Herschel Science Centre and presented by Herschel’s Project Scientist Göran Pilbratt during the opening session of The Universe Explored by Herschel symposium held at ESA’s ESTEC facility, in Noordwijk, the Netherlands, last month.

The animation runs from launch, on 14 May 2009, until the infrared observatory made its last observation on 29 April 2013.

Running through the center of the graphic is the ‘ecliptic plane’ tracing the paths of the planets with respect to Herschel’s viewpoint from its orbit around L2, which is located 1.5 million kilometers behind the Earth as viewed from the Sun.

A horseshoe shape marks the Galactic Plane, the direction in which much of the Milky Way’s mass lies, and where many of Herschel’s observations were focused.

In total, Herschel observed almost a tenth of the entire sky for over 23,500 hours, providing new views into the previously hidden Universe, pointing to unseen star birth and galaxy formation, and tracing water through the Universe from molecular clouds to newborn stars and to their planet-forming discs and belts of comets.

Its two camera/imaging spectrometers, PACS (Photoconductor Array Camera and Spectrometer) and SPIRE (Spectral and Photometric Imaging Receiver), which together covered wavelengths of 55–670 microns, provided about two thirds of Herschel’s sky coverage in parallel imaging mode. These data points are shown in yellow.

PACS and SPIRE photometry observations are indicated in blue and green, which together with spectroscopy performed with PACS, SPIRE and the third science instrument, HIFI (Heterodyne Instrument for the Far Infrared, covering wavelength bands of 157–212 microns and 240–625 microns) make up the remainder.

Since 29 October 2013, when the last observed data went public, all of the Herschel data are available to the worldwide astronomical community. The vast data archive will become the scientific legacy of the mission, destined to yield far more discoveries than have been made over the mission lifetime so far.

Video credit: ESA & P. Gómez-Alvarez / music: B. Lynne.

VLT and Hubble Images of the Protoplanet System HD 100546

This composite image shows a view from the NASA/ESA Hubble Space Telescope (left) and from the NACO system on ESO’s Very Large Telescope (right) of the gas and dust around the young star HD 100546. The Hubble visible-light image shows the outer disc of gas and dust around the star. The new infrared VLT picture of a small part of the disc shows a candidate protoplanet. Both pictures were taken with a special coronagraph that suppresses the light from the brilliant star. The position of the star is marked with a red cross in both panels.

Image credit: ESO/NASA/ESA/Ardila et al.

Note: For more information, see The Birth of a Giant Planet?

Messier 42 - The Orion Nebula

The Orion nebula is featured in this sweeping image from NASA's Wide-field Infrared Survey Explorer, or WISE. The constellation of Orion is prominent in the evening sky throughout the world from about December through April of each year. The nebula (also cataloged as Messier 42) is located in the sword of Orion, hanging from his famous belt of three stars. The star cluster embedded in the nebula is visible to the unaided human eye as a single star, with some fuzziness apparent to the most keen-eyed observers. Because of its prominence, cultures all around the world have given special significance to Orion. The Maya of Mesoamerica envision the lower portion of Orion, his belt and feet (the stars Saiph and Rigel), as being the hearthstones of creation, similar to the triangular three-stone hearth that is at the center of all traditional Maya homes. The Orion nebula, lying at the center of the triangle, is interpreted by the Maya as the cosmic fire of creation surrounded by smoke.

This metaphor of a cosmic fire of creation is apt. The Orion nebula is an enormous cloud of dust and gas where vast numbers of new stars are being forged. It is one of the closest sites of star formation to Earth and therefore provides astronomers with the best view of stellar birth in action. Many other telescopes have been used to study the nebula in detail, finding wonders such as planet-forming disks forming around newly forming stars. WISE was an all-sky survey giving it the ability to see these sites of star formation in a larger context. This view spans more than six times the width of the full moon, covering a region nearly 100 light-years across. In it, we see the Orion nebula surrounded by large amounts of interstellar dust, colored green.

Astronomers now realize that the Orion nebula is part of the larger Orion molecular cloud complex, which also includes the Flame nebula. This complex in our Milky Way galaxy is actively making new stars. It is filled with dust warmed by the light of the new stars within, making the dust glow in infrared light.

Color in this image represents specific infrared wavelengths. Blue represents light emitted at 3.4-micron wavelengths and cyan (blue-green) represents 4.6 microns, both of which come mainly from hot stars. Relatively cooler objects, such as the dust of the nebulae, appear green and red. Green represents 12-micron light and red represents 22-micron light.

Image credit: NASA/JPL-Caltech/UCLA

Note: For more information, see WISE Feels the Heat from Orion's Sword.

Protoplanetary Disk Around TW Hydrae

This illustration depicts the protoplanetary disc around the nearby young star TW Hydrae. With an age of about ten million years, TW Hydrae is located about 180 light-years away, towards the constellation Hydra, or the Sea Serpent.

Protoplanetary discs form around young stars from leftover material from the stellar formation process, which consists mainly of molecular hydrogen gas. This material orbits the star in a protoplanetary disc for several millions of years before it condenses into planets or is dispersed away by winds driven by the radiation of the star. In addition, trace amounts of cosmic dust and other gas species are present in the disc.

Astronomers using ESA's Herschel Space Observatory detected heavy molecular hydrogen in the protoplanetary disc around TW Hydrae, and have used this molecule as a tracer of the disc's main constituent – molecular hydrogen. This study has yielded the first accurate determination of the mass of a protoplanetary disc. With a mass equivalent to 50 times that of Jupiter, the disc around TW Hydrae is several times more massive than the primordial disc that gave birth to our Solar System.

At about ten million years, TW Hydrae is a relatively young star, but quite old to have retained a massive protoplanetary disc. The extremely accurate estimate of the disc's mass will benefit future observations of TW Hydrae and its environment, as astronomers investigate the various scenarios that could eventually lead to the formation of planets around this star.

Illustration credit: ESA/C. Carreau

Note: For more information, see Herschel Sizes Up Massive Protoplanetary Disc. Also, see PIA16683: Weighing Planetary Disks and Herschel Finds Past-Prime Star May Be Making Planets. Another post about TW Hydrae can be found here: Misty Star in the Sea Serpent.

ALMA Observations of the Disc and Gas Streams Around HD 142527

Observations made with the Atacama Large Millimeter/submillimeter Array (ALMA) telescope of the disc of gas and cosmic dust around the young star HD 142527, showing vast streams of gas flowing across the gap in the disc. These are the first direct observations of these streams, which are expected to be created by giant planets guzzling gas as they grow, and which are a key stage in the birth of giant planets.

The dust in the outer disc is shown in red. Dense gas in the streams flowing across the gap, as well as in the outer disc, is shown in green. Diffuse gas in the central gap is shown in blue. The gas filaments can be seen at the three o'clock and ten o'clock positions, flowing from the outer disc towards the center. The dense gas observed is HCO+, and the diffuse gas is CO. The outer disk is roughly two light-days across. If this were our own Solar System, the Voyager 1 probe — the most distant manmade object from Earth — would be at approximately the inner edge of the outer disk.

Image credit: ALMA (ESO/NAOJ/NRAO), S. Casassus et al.

Note: For more information, see ALMA Sheds Light on Planet-Forming Gas Streams.

Protoplanetary Disk Around a Brown Dwarf Star

This artist’s impression shows the disc of gas and cosmic dust around a brown dwarf.

Rocky planets are thought to form through the random collision and sticking together of what are initially microscopic particles in the disc of material around a star. These tiny grains, known as cosmic dust, are similar to very fine soot or sand. Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have for the first time found that the outer region of a dusty disc encircling a brown dwarf — a star-like object, but one too small to shine brightly like a star — also contains millimeter-sized solid grains like those found in denser discs around newborn stars. The surprising finding challenges theories of how rocky, Earth-scale planets form, and suggests that rocky planets may be even more common in the Universe than expected.

Illustration credit: ALMA (ESO/NAOJ/NRAO)/M. Kornmesser (ESO)

Note: For more information, see Even Brown Dwarfs May Grow Rocky Planets.

TYC 8241 2652: The Mysterious Case of the Disappearing Dust

Imagine if the rings of Saturn suddenly disappeared. Astronomers have witnessed the equivalent around a young sun-like star called TYC 8241 2652. Enormous amounts of dust known to circle the star are unexpectedly nowhere to be found.

"It's like the classic magician's trick: now you see it, now you don't. Only in this case we're talking about enough dust to fill an inner solar system and it really is gone!" said Carl Melis of the University of California, San Diego, who led the new study appearing in the July 5 issue of the journal Nature.

A dusty disk around TYC 8241 2652 was first seen by the NASA Infrared
Astronomical Satellite (IRAS) in 1983, and continued to glow brightly for 25 years. The dust was thought to be due to collisions between forming planets, a normal part of planet formation. Like Earth, warm dust absorbs the energy of visible starlight and reradiates that energy as infrared, or heat, radiation.

The first strong indication of the disk's disappearance came from images taken in January 2010 by NASA's Wide-field Infrared Survey Explorer, or WISE. An infrared image obtained at the Gemini telescope in Chile on May 1, 2012, confirmed that the dust has now been gone for two-and-a-half years.

"Nothing like this has ever been seen in the many hundreds of stars that astronomers have studied for dust rings," said co-author Ben Zuckerman of UCLA, whose research is funded by NASA. "This disappearance is remarkably fast even on a human time scale, much less an astronomical scale. The dust disappearance at TYC 8241 2652 was so bizarre and so quick, initially I figured that our observations must simply be wrong in some strange way."

The astronomers have come up with a couple of possible solutions to the mystery, but they say none are compelling. One possibility is that gas produced in the impact that released the dust helped to quickly drag the dust particles into the star and thus to their doom. In another possibility, collisions of large rocks left over from an original major impact provide a fresh infusion of dust particles into the disk, which caused the dust grains to chip apart into smaller and smaller pieces.

The result is based upon multiple sets of observations of TYC 8241 2652 obtained with the Thermal-Region Camera Spectrograph on the Gemini South telescope in Chile; IRAS; WISE; NASA's Infrared Telescope on Mauna Kea in Hawaii; the European Space Agency's Herschel Space Telescope, in which NASA plays an important role; and the Japanese/European Space Agency AKARI infrared satellite.

Illustration credit: NASA/JPL-Caltech

How Would the Solar System Look to Aliens?

Dust in the Kuiper Belt, the cold-storage zone that includes Pluto, creates a faint infrared disk potentially visible to alien astronomers looking for planets around the Sun. Neptune's gravitational imprint on the dust is detectable in new simulations of how this dust moves through the solar system. The simulations show how the distant view of the solar system might have changed over its history.

Video credit: NASA; text credit: NASA

A Star with Spiral Arms

For more than four hundred years, astronomers have used telescopes to study the great variety of stars in our galaxy. Millions of distant suns have been cataloged. There are dwarf stars, giant stars, dead stars, exploding stars, binary stars; by now, you might suppose that every kind of star in the Milky Way had been seen.

That's why a recent discovery is so surprising. Researchers using the Subaru telescope in Hawaii have found a star with spiral arms.

The name of the star is SAO 206462. It's a young star more than four hundred light years from Earth in the constellation Lupus, the wolf. SAO 206462 attracted attention because it has a circumstellar disk--that is, a broad disk of dust and gas surrounding the star. Researchers strongly suspected that new planets might be coalescing inside the disk, which is about twice as wide as the orbit of Pluto.

When they took a closer look at SAO 206462 they found not planets, but arms. Astronomers have seen spiral arms before: they’re commonly found in pinwheel galaxies where hundreds of millions of stars spiral together around a common core. Finding a clear case of spiral arms around an individual star, however, is unprecedented1.

The arms might be a sign that planets are forming within the disk.

"Detailed computer simulations have shown us that the gravitational pull of a planet inside a circumstellar disk can perturb gas and dust, creating spiral arms,” says Carol Grady, an astronomer with Eureka Scientific, Inc., who is based at NASA's Goddard Space Flight Center. “Now, for the first time, we're seeing these dynamical features."

Grady revealed the image to colleagues on October 19th at a meeting at Goddard entitled Signposts of Planets.

Theoretical models show that a single embedded planet may produce a spiral arm on each side of a disk. The structures around SAO 206462, however, do not form a matched pair, suggesting the presence of two unseen worlds, one for each arm.

Grady's research is part of a five-year international study of newborn stars and planets using the giant 8.2 meter Subaru Telescope. Operated by the National Astronomical Observatory of Japan, Subaru scans the heavens from a perch almost 14,000 feet above sea level at the summit of the Hawaiian volcano Mauna Kea. From there it has a crystal-clear view of innumerable young stars and their planet-forming disks throughout the Milky Way.

"What we're finding is that once these systems reach ages of a few million years—that’s young for a star--their disks begin to show all kinds of interesting shapes,” says John Wisniewski, a collaborator at the University of Washington in Seattle. "We’ve seen rings, divots, gaps--and now spiral features. Many of these structures could be caused by planets moving within the disks."

However, it is not an open and shut case. The research team cautions that processes unrelated to planets might give rise to these structures. Until more evidence is collected--or until the planets themselves are detected--they can’t be certain.

Whatever the cause of the arms, their reality is undeniable and the great catalog of stars has one more type.

Text credit: NASA; photo credit: NAOJ/Subaru

Misty Star in the Sea Serpent

This artist's concept illustrates an icy planet-forming disk around a young star called TW Hydrae, located about 175 light-years away in the Hydra, or Sea Serpent, constellation. Astronomers using the Herschel Space Observatory detected copious amounts of cool water vapor, illustrated in blue, emanating from the star's planet-forming disk of dust and gas. The water vapor, which probably comes from icy grains in the disk, is located in the frigid outer regions of the star system, where comets will take shape.

In our own solar system, comets are thought to have carried water to Earth, creating our oceans. A similar process might be taking place around TW Hydrae -- comets could, over the next several millions of years, transport water to young worlds. The Herschel results demonstrate that vast reservoirs of water are available around stars for creating these hypothetical water worlds.

The graph of data (Figure 1) from Herschel shows how the cool water vapor was detected. Water molecules come in two "spin" forms, called ortho and para, in which the two spins of the hydrogen nuclei have different orientations. In this case, the team compared the ratio of ortho to para water seen in the TW Hydrae disk to that in comets, and found very low values. Lower ratios indicate cooler temperatures, though in practice the analysis is much more complicated. This is the first demonstration that water exists in large quantities in the frigid, outer regions of solar systems, where comets take shape.

Illustration credit: ESA/NASA/JPL-Caltech/Leiden Observatory

Note: For more information, see Herschel Discovers Tip of Cosmic Iceberg Around Nearby Young Star.

Protoplanetary Disk Around Star T Chamaeleontis

Using ESO’s Very Large Telescope an international team of astronomers has been able to study the short-lived disc of material around a young star that is in the early stages of making a planetary system. For the first time a smaller companion could be detected that may be the cause of the large gap found in the disc. Future observations will determine whether this companion is a planet or a brown dwarf.

Planets form from the discs of material around young stars, but the transition from dust disc to planetary system is rapid and few objects are caught during this phase [1]. One such object is T Chamaeleontis (T Cha), a faint star in the small southern constellation of Chamaeleon that is comparable to the Sun, but very near the beginning of its life [2]. T Cha lies about 350 light-years from the Earth and is only about seven million years old. Up to now no forming planets have been found in these transitional discs, although planets in more mature discs have been seen before (eso0842, heic0821).

“Earlier studies had shown that T Cha was an excellent target for studying how planetary systems form,” notes Johan Olofsson (Max Planck Institute for Astronomy, Heidelberg, Germany), one of the lead authors of two papers in the journal Astronomy & Astrophysics that describe the new work. “But this star is quite distant and the full power of the Very Large Telescope Interferometer (VLTI) was needed to resolve very fine details and see what is going on in the dust disc.”

The astronomers first observed T Cha using the AMBER instrument and the VLT Interferometer (VLTI) [3]. They found that some of the disc material formed a narrow dusty ring only about 20 million kilometers from the star. Beyond this inner disc, they found a region devoid of dust with the outer part of the disc stretching out into regions beyond about 1.1 billion kilometers from the star.

Nuria Huélamo (Centro de Astrobiología, ESAC, Spain), the lead author of the second paper takes up the story: “For us the gap in the dust disc around T Cha was a smoking gun, and we asked ourselves: could we be witnessing a companion digging a gap inside its protoplanetary disc?”

However, finding a faint companion so close to a bright star is a huge challenge and the team had to use the VLT instrument NACO in a novel and powerful way, called sparse aperture masking, to reach their goal [4]. After careful analysis they found the clear signature of an object located within the gap in the dust disc, about one billion kilometers from the star — slightly further out than Jupiter is within our Solar System and close to the outer edge of the gap. This is the first detection of an object much smaller than a star within a gap in the planet-forming dust disc around a young star. The evidence suggests that the companion object cannot be a normal star [5] but it could be either a brown dwarf [6] surrounded by dust or, most excitingly, a recently formed planet.

Huélamo concludes: “This is a remarkable joint study that combines two different state-of-the-art instruments at ESO’s Paranal Observatory. Future observations will allow us to find out more about the companion and the disc, and also understand what fuels the inner dusty disc.”

Notes:

[1] The transitional discs can be spotted because they give off less radiation at mid-infrared wavelengths. The clearing of the dust close to the star and the creation of gaps and holes can explain this missing radiation. Recently formed planets may have created these gaps, although there are also other possibilities.

[2] T Cha is a T Tauri star, a very young star that is still contracting towards the main sequence.

[3] The astronomers used the AMBER instrument (Astronomical Multi-BEam combineR) and the VLTI to combine the light from all four of the 8.2-meter VLT Unit Telescopes and create a “virtual telescope” 130 meters across.

[4] NACO (or NAOS–CONICA in full) is an adaptive optics instrument attached to ESO’s Very Large Telescope. Thanks to adaptive optics, astronomers can remove most of the blurring effect of the atmosphere and obtain very sharp images. The team used NACO in a novel way, called sparse aperture masking (SAM) to search for the companion. This is a type of interferometry that, rather than combining the light from multiple telescopes as the VLTI does, uses different parts of the mirror of a single telescope (in this case, the mirror of the VLT Unit Telescope 4). This new technique is particularly good for finding faint objects very close to bright ones. VLTI/AMBER is better suited to studying the structure of the inner disc and is less sensitive to the presence of a distant companion.

[5] The astronomers searched for the companion using NACO in two different spectral bands — at around 2.2 microns and at 3.8 microns. The companion is only seen at the longer wavelength, which means that the object is either cool, like a planet, or a dust-shrouded brown dwarf.

[6] Brown dwarfs are objects between stars and planets in size. They are not massive enough to fuse hydrogen in their cores but are larger than giant planets such as Jupiter.

Image credit: ESO/L. Calçada

Orion Nebula Proplyd Atlas

This atlas features 30 proplyds, or protoplanetary discs, that were recently discovered in the majestic Orion Nebula. Using the wide field channel on Hubble's Advanced Camera for Surveys (ACS), astronomers discovered a total of 42 new discs that could be the seeds of planetary systems to come.

Within the awe-inspiring, gaseous folds of Orion, researchers have identified two different types of discs around young and forming stars: those that lie close to the brightest star in the cluster (Theta 1 Orionis C) and those farther away from it. The bright star heats up the gas in the nearby discs, causing them to shine brightly. The discs that are farther away do not receive enough of the energetic radiation from the star to set the gas ablaze; thus, they can only be detected as dark silhouettes against the background of the bright nebula, as the dust that surrounds these discs absorbs background visible light. By studying these silhouetted discs, astronomers are better able to characterize the properties of the dust grains that are thought to bind together and possibly form planets like our own.

In the brighter discs the excited material produces many glowing cusps, which all face the bright star, but from our point of view are randomly oriented through the nebula, so we see some edge on, and others face on, for instance. Other interesting features enhance the look of these captivating objects, such as emerging jets of matter and shock waves. The dramatic shock waves are formed when the stellar wind from the nearby massive star collides with the gas in the nebula, sculpting boomerang shapes or arrows or even, in the case of 181-825, a space jellyfish!

It is relatively rare to see visible images of proplyds, but the high resolution and sensitivity of Hubble and the Orion Nebula's proximity to Earth allow for precise views of these potential planetary systems.

...

The full set of individual images of the 30 proplyds can be accessed on the dedicated pages at the spacetelescope.org website. See the related link "Proplyd Atlas - Orion Nebula."

Photo credit: NASA/ESA and L. Ricci (ESO)

Beta Pictoris b

This story is a little old, having come out back in June, but there aren't any other new stories to report on at the moment.

For the first time, astronomers have been able to directly follow the motion of an exoplanet as it moves to the other side of its host star. The planet has the smallest orbit so far of all directly imaged exoplanets, lying as close to its host star as Saturn is to the Sun.

The team of astronomers used the NAOS-CONICA instrument (or NACO), mounted on one of the 8.2-meter Unit Telescopes of ESO's Very Large Telescope (VLT), to study the immediate surroundings of Beta Pictoris in 2003, 2008 and 2009. In 2003 a faint source inside the disc was seen, but it was not possible to exclude the remote possibility that it was a background star. In new images taken in 2008 and spring 2009 the source had disappeared! The most recent observations, taken during autumn 2009, revealed the object on the other side of the disc after having been hidden either behind or in front of the star. This confirmed that the source indeed was an exoplanet and that it was orbiting its host star. It also provided insights into the size of its orbit around the star.

The above composite shows the reflected light on the dust disc in the outer part, as observed in 1996 with the ADONIS instrument on ESO's 3.6-meter telescope. In the central part, the observations of the planet obtained in 2003 and autumn 2009 with NACO are shown. The possible orbit of the planet is also indicated, albeit with the inclination angle exaggerated.

Photo credit: ESO/A.-M. Lagrange

Star IRAS 13481-6124 and Nebula

This star-forming region, captured by NASA's Spitzer Space Telescope, is dominated by the bright, young star IRAS 13481-6124 (upper left), which is about twenty times the mass of our sun and five times its radius, and is surrounded by its pre-natal cocoon. It is the first massive baby star for which astronomers could obtain a detailed look at the dusty disk closely encircling it. The research provides direct evidence that massive stars do form in the same way as their smaller brethren.

From this archival Spitzer image, as well as from observations done with the APEX 12-meter sub-millimeter telescope, astronomers discovered the presence of a jet, hinting at the presence of a disk. This was then confirmed by observations made with the European Southern Observatory Very Large Telescope Interferometer.

This picture was taken with Spitzer's infrared array camera. It is a four-color composite, in which light with a wavelength of 3.6 microns is blue; 4.5-micron light is green; 5.8-micron light is orange; and 8-micron light is red. Dust appears red-orange and most stars are blue, though ones deeply embedded within dust (like IRAS 13481-6124) take on greenish-yellow tints.

Photo credit: NASA/JPL-Caltech/ESO/Univ. of Michigan
Illustration credit: ESO/L. Calçada

Notes: For more information, see Unravelling the Mystery of Massive Star Birth. This star is located roughly 10,000 light-years away in the constellation of Centaurus.