Posted on by Nancy Atkinson

Hubble Telescope Captures Image of Comet ISON

Comet ISON was used in a search for time travelers. NASA’s Hubble Space Telescope provides a close-up look of Comet ISON (C/2012 S1), as photographed on April 10. Credit: NASA, ESA, J.-Y. Li (Planetary Science Institute), and the Hubble Comet ISON Imaging Science Team.

Here’s our first good look at Comet (C/2012 S1) ISON. The Hubble Space Telescope captured this shot on April 10, when the comet was slightly closer than Jupiter’s orbit at a distance of 634 million kilometers (394 million miles) from Earth. Later this year, this comet could become a brilliant object in the sky, perhaps 10 times brighter than Venus.

Astronomers say preliminary measurements from the Hubble images suggest that the nucleus of ISON is no larger than 4-6 km (3-4 miles) across.


The astronomers said this is remarkably small considering the high level of activity observed in the comet so far. Astronomers are using these images to measure the activity level of this comet and constrain the size of the nucleus, in order to predict the comet’s activity when it will come with 1.1 million km (700,000 miles) of the Sun on November 28, 2013.

Even though Comet ISON was 620 million km from the Sun when this image was taken, the comet is already active as sunlight warms the surface and causes frozen volatiles to sublimate. A detailed analysis of the dust coma surrounding the solid, icy nucleus reveals a strong, jet blasting dust particles off the sunward-facing side of the comet’s nucleus.

The comet’s dusty coma, or head of the comet, is approximately 5,000 km (3,100 miles) across, or 1.2 times the width of Australia. A dust tail extends more than 92,000 km (57,000 miles), far beyond Hubble’s field of view.

Comet ISON belongs to a special category of comets called sungrazers. As the comet performs a hairpin turn around the Sun in November, its ices will vaporize in the intense solar heat. Assuming it defies death by evaporation, some predict it could become as bright as the full Moon. If so, that would occur for a brief time around at perihelion (closest approach to the Sun) when the comet would only be visible in the daytime sky very close to the Sun. When safely viewed, ISON might look like a brilliant, fuzzy star in a blue sky.

More careful analysis is currently underway to improve these measurements and to predict the possible outcome of the sungrazing perihelion passage of this comet.

ISON stands for International Scientific Optical Network, a group of observatories in ten countries who have organized to detect, monitor, and track objects in space. ISON is managed by the Keldysh Institute of Applied Mathematics, part of the Russian Academy of Sciences.

Source: NASA

Posted on by Nancy Atkinson

A New Look at the Horsehead Nebula for Hubble’s 23rd Anniversary

A new view of the Horsehead Nebula in infrared. Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA).

Here’s the iconic Horsehead Nebula as we’ve not seen it before. As the Hubble team so poetically puts it, the nebula looks “like an apparition rising from whitecaps of interstellar foam.” The new image of the Horsehead was photographed in celebration of the 23rd anniversary of the launch of Hubble aboard the space shuttle Discovery, on April 24, 1990.

Can you believe the Hubble Space Telescope has been in space for 23 years? … and it’s been churning out great images for almost 20 years since it was fixed in space during the first Hubble servicing mission in 1993.

This view shows the nebula in infrared wavelengths. When seen in optical light (see below), it appears dark and shadowy, but is “transparent and ethereal when seen in the infrared, represented here with visible shades. The rich tapestry of the Horsehead Nebula pops out against the backdrop of Milky Way stars and distant galaxies that are easily seen in infrared light,” the Hubble team said.

Gas clouds surrounding the Horsehead have already dissipated, but the tip of the jutting pillar contains a slightly higher density of hydrogen and helium, laced with dust. This casts a shadow that protects material behind it from being photo-evaporated, and a pillar structure forms. Astronomers estimate that the Horsehead formation has about five million years left before it too disintegrates.

The Horsehead Nebula is part of a much larger complex in the constellation Orion. Known collectively as the Orion Molecular Cloud, it also houses other famous objects such as the Great Orion Nebula (M42), the Flame Nebula, and Barnard’s Loop. At about 1,500 light-years away, this complex is one of the nearest and most easily photographed regions in which massive stars are being formed.

Hubble’s pairing of infrared sensitivity and unparalleled resolution offers a tantalizing hint of what the upcoming James Webb Space Telescope, set for launch in 2018, will be able to do.

Here’s a view in optical from Hubble:

The Horsehead Nebula is a cold, dark cloud of gas and dust, silhouetted against the bright nebula IC 434. The bright area at the top left edge is a young star still embedded in its nursery of gas and dust. Image Credit: NASA, NOAO, ESA and The Hubble Heritage Team (STScI/AURA)
The Horsehead Nebula is a cold, dark cloud of gas and dust, silhouetted against the bright nebula IC 434. The bright area at the top left edge is a young star still embedded in its nursery of gas and dust.
Image Credit: NASA, NOAO, ESA and The Hubble Heritage Team (STScI/AURA)

For more details, see the HubbleSite

Posted on by Nancy Atkinson

Hubble Telescope Breaks Record in Finding Most Distant Type Ia Supernova

This is a NASA/ESA Hubble Space Telescope view looking long ago and far away at a supernova that exploded over 10 billion years ago — the most distant Type Ia supernova ever detected. The supernova’s light is just arriving at Earth, having travelled more than 10 billion light-years (redshift 1.914) across space. Credit: NASA, ESA, A. Riess (STScI and JHU), and D. Jones and S. Rodney (JHU).

Astronomers just keep honing their skills and refining their techniques to get the most out of their telescopes. Scientists using the Hubble Space Telescope have now broken the record for the most distant Type Ia supernova ever imaged. This supernova is over 10 billion light-years away, with a redshift of 1.914. When this star exploded 10 billion years ago, the Universe was in its early formative years and stars were being born at a rapid rate.

“This new distance record holder opens a window into the early Universe, offering important new insights into how these supernovae form,” said astronomer David O. Jones of The Johns Hopkins University in Baltimore, Md., lead author on the science paper detailing the discovery. “At that epoch, we can test theories about how reliable these detonations are for understanding the evolution of the Universe and its expansion.”

These three frames show the supernova dubbed SN UDS10Wil, or SN Wilson, the most distant Type Ia supernova ever detected. The leftmost frame in this image shows just the supernova’s host galaxy, before the violent explosion. The middle frame shows the galaxy after the supernova had gone off, and the third frame indicates the brightness of the supernova alone. Credit: NASA, ESA, A. Riess (STScI and JHU), and D. Jones and S. Rodney (JHU)
These three frames show the supernova dubbed SN UDS10Wil, or SN Wilson, the most distant Type Ia supernova ever detected. The leftmost frame in this image shows just the supernova’s host galaxy, before the violent explosion. The middle frame shows the galaxy after the supernova had gone off, and the third frame indicates the brightness of the supernova alone. Credit: NASA, ESA, A. Riess (STScI and JHU), and D. Jones and S. Rodney (JHU)

Designated as SN UDS10Wil (and nicknamed SN Wilson after American President Woodrow Wilson (president from 1913-1921), the distant supernova was part of a three-year Hubble program to survey faraway Type Ia supernovae and determine whether they have changed during the 13.8 billion years since the explosive birth of the universe. Since 2010, the CANDELS+CLASH Supernova Project has uncovered more than 100 supernovae of all types that exploded from 2.4 to over 10 billion years ago.

The previous record holder for Type Ia was announced earlier this year, a supernova that exploded around 9 billion years ago and has a redshift of 1.7. Although SN Wilson is only 4 percent more distant than the previous record holder, it pushes roughly 350 million years farther back in time.

The most distant supernovae ever are a pair of super-luminous supernovae, at redshifts of 2.05 and 3.90, announced in November 2012. Read about that discovery here.

Astronomers took advantage of the sharpness and versatility of Hubble’s Wide Field Camera 3 to search for supernovae in near-infrared light and verify their distance with spectroscopy. These bright beacons are prized by astronomers because they can be used as a yardstick for measuring cosmic distances, thereby yielding clues to the nature of dark energy, the mysterious force accelerating the rate of expansion of the Universe.

Additionally, finding remote supernovae provides a powerful method to measure the universe’s accelerating expansion.

“The Type Ia supernovae give us the most precise yardstick ever built, but we’re not quite sure if it always measures exactly a yard,” said team member Steve Rodney of Johns Hopkins University. “The more we understand these supernovae, the more precise our cosmic yardstick will become.”

Read the team’s paper: The Discovery of the Most Distant Known Type Ia Supernova at Redshift 1.914

Sources: NASA, ESA

Posted on by Nancy Atkinson

NASA Finds a Space Invader

The image of a spiral galaxy has been stretched and mirrored by gravitational lensing into a shape similar to that of a simulated alien from the classic 1970s computer game Space Invaders Credit: NASA, ESA, and the Hubble Heritage/ESA-Hubble Collaboration

Pew pew! NASA has found a Space Invader, but they won’t be activating any laser cannons to shoot it down. If you remember the classic 1970s computer game “Space Invaders,” you’ll quickly see the resemblance of the game’s pixelated alien to this actual image from the Hubble Space Telescope. This strange-looking object is really a mirage created by the gravitational field of a foreground cluster of galaxies warping space and distorting the background images of more distant galaxies.

Here, Abell 68, a massive cluster of galaxies, acts as a natural lens in space to brighten and magnify the light coming from very distant background galaxies. Just like a fun house mirror, lensing creates a fantasy landscape of arc-like images and mirror images of background galaxies. The foreground cluster is 2 billion light-years away, and the lensed images come from galaxies far behind it.

This image was taken in infrared light by Hubble’s Wide Field Camera 3, and combined with near-infrared observations from Hubble’s Advanced Camera for Surveys.

Aliens from the Space Invaders game. Via HelloComputer.
Aliens from the Space Invaders game. Via HelloComputer.

The image was found as part of Hubble’s Hidden Treasures image processing competition, and was spotted by Nick Rose.

You can still play the Space Aliens game (just search for it online), or you might want to try this huge version:

Source: NASA

Posted on by Nancy Atkinson

Distant Star Goes Disco

Star-forming Region IC 348 Around Protostar LRLL 54361. Credit: Credit: NASA, ESA, J. Muzerolle (STScI), E. Furlan (NOAO and Caltech), K. Flaherty (University of Arizona/Steward Observatory), Z. Balog (Max Planck Institute for Astronomy), and R. Gutermuth (University of Massachusetts, Amherst)

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

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

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

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

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

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

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

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

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

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

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

Read Muzerolle’s paper (pdf)

Source: HubbleSite

Posted on by John Williams

Region in LMC Ablaze with Light and Color

Nearly 200 000 light-years from Earth, the Large Magellanic Cloud, a satellite galaxy of the Milky Way, floats in space, in a long and slow dance around our galaxy. As the Milky Way’s gravity gently tugs on its neighbour’s gas clouds, they collapse to form new stars. In turn, these light up the gas clouds in a kaleidoscope of colours, visible in this image from the NASA/ESA Hubble Space Telescope.

Hubble view of star formation region N11 from the NASA/ESA Hubble Space Telescope. Image credit: NASA/ESA Hubble. Zoom by John Williams/TerraZoom using Zoomify.

New computer wallpaper alert. Light from the Large Magellanic Cloud takes nearly 200,000 years to travel to Earth. And it’s worth the wait.

Behold LHA 120-N 11, or just simply N11, in this image from the NASA/ESA Hubble Space Telescope.

Continue reading “Region in LMC Ablaze with Light and Color”

Posted on by John Williams

Combining Light to Reveal Monster Black Holes

NGC 3627 glows in the combined light of Hubble, Chandra, Spitzer and the Very Large Telescope in this image. Astronomers conducted a survey of 62 galaxies, including NGC 3627 to study monster black holes at their centers.

It’s not just pretty, it’s science. Like a starry watercolor, astronomers combining light from Earth and space-based observatories found 37 new supermassive black hole candidates lurking in nearby galaxies.

Included in that survey is NGC 3627 pictured above. Astronomers combined X-ray data from NASA’s Chandra X-ray Observatory, infrared data from the Spitzer Space Telescope, and optical data from the Hubble Space Telescope and the Very Large Telescope. The other images give the galaxy context but it’s the ghostly blue images from Chandra that show super bright in the X-ray images; X-ray light powered by material falling into a monster black hole.

Gas and dust slowly spins around the black hole creating a flattened disk, or accretion disk. As material falls inward, it heats up and releases large amounts of energy that shine brightly in the ultraviolet region of the spectrum.

NGC 3627, located about 30 million light-years from Earth, was just one of a survey of 62 nearby galaxies using archived data from Chandra and data from the Spitzer Infrared Nearby Galaxy Survey. Of those, 37 galaxies contained bright X-ray sources, indicating active black holes at their cores. Scientists believe that seven of those sources are new supermassive black hole candidates.

The paper describing the survey results was published in the April 10, 2011 issue of The Astrophysical Journal.

Combining ultraviolet and infrared observations confirm previous Chandra results that found that there may be many more galaxies powered by monster black holes than believed previously through optical surveys. Scientists say in the paper that low-levels of black hole activity previously may have been hidden by dust or washed out by the bright light of the galaxy.

Image caption: Bright X-ray sources glow a ghostly blue in this image in NGC 3627 from NASA’s Chandra X-ray Observatory. A study confirms previous Chandra results that indicate that more galaxies powered by monster black holes populate the cosmos.

Source: Chandra X-ray Observatory website

Posted on by John Williams

Pink Galactic Smackdown Results in Cosmic Bulls-eye

Bright pink nebulae encircle spiral galaxy NGC 922 in this image from the NASA/ESA Hubble Space Telescope. Credit: NASA/ESA. Zoom: John Williams/TerraZoom and Zoomify

Galaxies pack a wallop. A galactic bulls-eye ringed with pink nebulae is the only evidence of a rare galactic collision of NGC 922 that occurred millions of years ago. Clicking the button on the far right of the toolbar will allow awesomecosmicsauce to tantalize your eyes and work all of the pixels on your computer screen. Pressing the “ESC” will return you to the present universe.

Explore this awesome image from the NASA/ESA Hubble Space Telescope. While lovely, something is amiss in this image. NGC 922 used to be a spiral galaxy. As you zoom across the image, the spiral arms look distorted and disrupted. Hints of a galactic interaction are strewn across the galaxy from the large numbers of bright pink nebulae and blue stars to the spray of dim stars toward the top of the image. Ripples set up as the smaller galaxy passed through the gas and dust clouds of NGC 922 created new star formation. Ultraviolet radiation from these bright new stars cause hydrogen gas in the surrounding nebula to glow a characteristic pink. The tugs of gravity hurled thousands of stars outward.

Episode 60 of the Hubblecast explores NGC 922, a galaxy that has been hit square-on by another. Ripples of star-formation are still propagating out across thousands of light-years of space over 300 million years after the collision, making it a prime example of what astronomers call a collisional ring galaxy.

Scientists believe that millions of years ago a small galaxy, known as 2MASXI J0224301-244443, plunged through the heart of NGC 922. Sometimes, if a small galaxy hits a larger galaxy just right, a circle is formed. But more often than not, galaxies are not aligned perfectly. When a galaxy smacks another off center, one side of the ring is brighter than the other. NGC 922 is a prime example of what astronomers call collisional ring galaxies. Although only a few ring galaxies are seen in our cosmic neighborhood, of which the Cartwheel Galaxy is the most spectacular, ring galaxies appear to be commonplace as we peer further into the past.

As you explore the empty places of the image, look for faraway background galaxies. Several dim spiral galaxies dot the image both outside the galaxy and within the star-speckled interior.

NGC 922 is found about 330 million light-years from Earth toward the constellation Fornax. Sky mapper and French astronomer Nicolas Louis de Lacaille introduced Fornax, the Furnace, in 1756. Fornax is relatively devoid of stars allowing astronomers to peer deep into the universe. The constellation was the perfect target for the Hubble Ultra Deep Field image.

NASA/ESA Hubble Space Telescope image of NGC 922. Credit: NASA, ESA

Source: ESA Hubble

Posted on by Nancy Atkinson

Stunning Gallery of Previously Unpublished Images from “Hubble’s Universe”

Distant star-forming region NGC 2467. Credit: NASA/ESA, Courtesy of “Hubble’s Universe.”

The new book, Hubble’s Universe: Greatest Discoveries and Latest Images includes several previously unpublished images from the Hubble Space Telescope, and author Terence Dickinson has graciously shared a few of those images with Universe Today. All images are courtesy of NASA, ESA, and “Hubble’s Universe.”

Find out how you can win a copy of “Hubble’s Universe” here.

Read our full review of this book here.

Above is NGC 2467, a nebula similar to the Orion Nebula, but 11 times farther away, in the southern constellation Puppis. A churning foam of strangely shaped dust clouds forms the backdrop to the newborn blue stars emerging from the gas and dust. Most of the radiation that is eating away at the cloud is being emitted by the single brilliant massive star near the center of the image. Its fierce radiation has cleared the surrounding area, and some of the next generation of stars are forming in the denser regions around the edge.

See more beautiful Hubble images below:

The star cluster NGC2060 contains a supernova that exploded about 10,000 years ago, blowing out gas surrounding the cluster.

A celestial shell of interstellar gas being shocked by the blast wave from a supernova, the Ornament Nebula was imaged by the Hubble Space Telescope and combined with X-ray images from NASA’s Chandra X-ray Observatory. The supernova – the explosive destruction of a star – occurred nearly 400 years ago and is 23 light-years across. The nebula is expanding at the rate of the Earth-to-Moon distance every minute.

Glorious Saturn. This exquisite Hubble portrait of Saturn shows the famous rings nearly edge-on. Some of the larger of Saturn’s more than five dozen moons are seen, including most prominently Titan, the largest, casting its inky shadow on the planet. The rings are composed of trillions of icy particles that probably originated with the collision of large moons aeons ago.

Egg Nebula. Concentric dust layers extend over one-tenth of a light-year from this dying sun. Running almost vertically through the image, a thick dust belt blocks the light of the central star. Twin beams of light radiate from the hidden star, illuminating the pitch-black dust like a flashlight shining in a smoky room. The nebula was photographed through polarizing filters to measure how the dust reflects light.

NGC6384. Star birth in this relatively quiescent middle-aged galaxy has declined. Noticeably missing are pinkish nebulas that are the sites of new star formation. Radiation and stellar winds from superhot, young blue stars have cleared out the remaining gas, shutting down any further production of stars. A bright concentration of starlight marks the galaxy’s center. Spiraling outward, dust lanes are silhouetted against the population of whitish middle-aged stars. Much younger blue stars trace the spiral arms.

ARP 273. A cosmic waltz between two galaxies is the result of gravitational tidal distortion from their close proximity to each other. Despite the fact that they are separated by tens of thousands of light-years, a tenuous tidal bridge of material stretches between the pair. The swath of blue across the top is the combined light from clusters of bright, hot, young blue stars, The smaller, nearly edge-on companion galaxy shows intense star formation at its nucleus, which was probably triggered by the interactions. More close encounters and an eventual merger are the likely future of this galaxy duo.

Stephan’s Quintet. One of the most famous examples of interacting galaxies is Stephan’s Quintet. Three of the galaxies have distorted shapes, elongated spiral arms and long, gaseous tidal tails containing myriad star clusters. The interactions among the galaxies have sparked a frenzy of star birth in the pair of intertwined galaxies just above center. This drama is being played out against a rich background of far more distant galaxies. The galaxy at lower left is in the foreground and not part of the grouping. It is 40 million light-years from Earth, while the remaining members of the quintet reside 290 million light-years away.

Galaxy Panorama. This is just 1 of 10 photos of that create a panorama of distant galaxies. Perhaps better than anything else in this book, these images open a window on the universe of galaxies – arguably, the Hubble Space Telescopes’ greatest gift so far. The image reveals a rich tapestry of thousands of galaxies stretching back through most of the universe’s history. The closest galaxies in the foreground emitted their observed light about a billion years ago. The most distant galaxies, a few of the very faint red specks, are seen as they appeared more than 13 billion years ago. The image combines a broad range of colors, from the ultraviolet, through visible light and into the near infrared. Such a detailed view of the deep universe in this combination of color, clarity, accuracy and depth has never before been assembled. The panorama shows galaxy shapes that, at each earlier epoch, appear increasingly chaotic as galaxies grew through accretion, collisions and mergers. The galaxies range from the mature spirals and elliptical in the foreground to smaller, fainter, irregularly shaped galaxies, most of which are farther away and, therefore, existed further back in time. The smaller galaxies are considered the building blocks of the large galaxies we see today.

Ants in space? Designated Menzel 3 (Mz 3), and called the Ant Nebula, this member of Hubble’s celestial menagerie resembles the head and thorax of a garden ant. The central star in Mz3 might have a closely orbiting companion that is exerting strong gravitational tidal forces which are shaping the outflowing gas. The very massive young star Eta Carinae shows a similar outflow pattern to that of Mz3.

The Hubble Space Telescope captured this image of the 86-kilometer-wide lunar impact crater Tycho. Because the Moon has been mapped in great detail by lunar orbiting spacecraft, there is relatively little call for Hubble’s intense gaze to be turned toward the Earth’s natural satellite.

This image was published earlier this year, and shows the dazzling globular star cluster Messier 9, or simply M9, contains hordes of stars swarming in a spherical cloud about 25,000 light-years from Earth. It is too faint to be seen with the naked eye, and when it was discovered by French astronomer Charles Messier in 1764, he observed it only as a faint smudge in his small telescope. He classified the cluster as a nebula (“cloud” in Latin). This Hubble Space Telescope portrait, the best image yet of M9, reveals 250,000 individual stars.

Posted on by Nancy Atkinson

Now Even Further: Ancient Galaxy is Latest Candidate for Most Distant

It seems that every few months or so comes a new discovery of a new “most distant galaxy ever found.” It’s not really a surprise that new benchmarks are reached with such an amazing frequency as our telescopes get better and astronomers refine their techniques for observing faraway and ancient objects. This latest “most distant” is pretty interesting in that it was found by combining observations from two space telescopes – Hubble and Spitzer – as well as using massive galaxy clusters as gravitational lenses to magnify the distant galaxy behind them. It’s also extremely small and may not even be a fully developed galaxy at the time we are seeing it.

While this galaxy, named MACS0647-JD, appears as a diminutive blob in the new images, astronomers say it offers a peek back into a time when the universe was just 3 percent of its present age of 13.7 billion years. This newly discovered galaxy was observed 420 million years after the Big Bang, and its light has traveled 13.3 billion years to reach Earth.

“This object may be one of many building blocks of a galaxy,” said Dan Coe of the Space Telescope Science Institute, lead author of a new paper on the observations. “Over the next 13 billion years, it may have dozens, hundreds, or even thousands of merging events with other galaxies and galaxy fragments.”

The discovery comes from the Cluster Lensing And Supernova Survey with Hubble (CLASH), a program that combines the power of space telescopes with the natural zoom of gravitational lensing to reveal distant galaxies in the early Universe. Observations with Spitzer’s infrared eyes allowed for confirmation of this object.

The light from MACS0647-JD was magnified by a massive galaxy cluster named MACS J0647+7015, and without the cluster’s magnification powers, astronomers would not have seen the remote galaxy. Because of gravitational lensing, the CLASH research team was able to observe three magnified images of MACS0647-JD with the Hubble telescope. The cluster’s gravity boosted the light from the faraway galaxy, making the images appear about eight, seven, and two times brighter than they otherwise would that enabled astronomers to detect the galaxy more efficiently and with greater confidence.

“This cluster does what no manmade telescope can do,” said Marc Postman, also from STScI. “Without the magnification, it would require a Herculean effort to observe this galaxy.”

MACS0647-JD is just a fraction of the size of our Milky Way galaxy, and is so small it may not even be a fully formed galaxy. Data show the galaxy is less than 600 light-years wide. Based on observations of somewhat closer galaxies, astronomers estimate that a typical galaxy of a similar age should be about 2,000 light-years wide. For comparison, the Large Magellanic Cloud, a dwarf galaxy companion to the Milky Way, is 14,000 light-years wide. Our Milky Way is 150,000 light-years across.

Loading player…

The galaxy was observed with 17 filters, spanning near-ultraviolet to near-infrared wavelengths, using Hubble’s Wide Field Camera 3 (WFC3) and Advanced Camera for Surveys (ACS). Coe discovered the galaxy in February while poring over a catalogue of thousands of gravitationally lensed objects found in Hubble observations of 17 clusters in the CLASH survey. But the galaxy appeared only in the two reddest filters.

“So either MACS0647-JD is a very red object, only shining at red wavelengths, or it is extremely distant and its light has been ‘redshifted’ to these wavelengths, or some combination of the two,” Coe said. “We considered this full range of possibilities.”

The CLASH team identified multiple images of eight galaxies lensed by the galaxy cluster. Their positions allowed the team to produce a map of the cluster’s mass, which is primarily composed of dark matter. Dark matter is an invisible form of matter that makes up the bulk of the universe’s mass. “It’s like a big puzzle,” said Coe. “We have to arrange the mass in the cluster so that it deflects the light of each galaxy to the positions observed.” The team’s analysis revealed that the cluster’s mass distribution produced three lensed images of MACS0647-JD at the positions and relative brightness observed in the Hubble image.

Coe and his collaborators spent months systematically ruling out these other alternative explanations for the object’s identity, including red stars, brown dwarfs, and red (old or dusty) galaxies at intermediate distances from Earth. They concluded that a very distant galaxy was the correct explanation.

Redshift is a consequence of the expansion of space over cosmic time. Astronomers study the distant universe in near-infrared light because the expansion of space stretches ultraviolet and visible light from galaxies into infrared wavelengths. Coe estimates MACS0647-JD has a redshift of 11, the highest yet observed.

Images of the galaxy at longer wavelengths obtained with the Spitzer Space Telescope played a key role in the analysis. If the object were intrinsically red, it would appear bright in the Spitzer images. Instead, the galaxy barely was detected, if at all, indicating its great distance. The research team plans to use Spitzer to obtain deeper observations of the galaxy, which should yield confident detections as well as estimates of the object’s age and dust content.

MACS0647-JD galaxy, however, may be too far away for any current telescope to confirm the distance based on spectroscopy, which spreads out an object’s light into thousands of colors. Nevertheless, Coe is confident the fledgling galaxy is the new distance champion based on its unique colors and the research team’s extensive analysis. “All three of the lensed galaxy images match fairly well and are in positions you would expect for a galaxy at that remote distance when you look at the predictions from our best lens models for this cluster,” Coe said.

The new distance champion is the second remote galaxy uncovered in the CLASH survey, a multi-wavelength census of 25 hefty galaxy clusters with Hubble’s ACS and WFC3. Earlier this year, the CLASH team announced the discovery of a galaxy that existed when the universe was 490 million years old, 70 million years later than the new record-breaking galaxy. So far, the survey has completed observations for 20 of the 25 clusters.

The team hopes to use Hubble to search for more dwarf galaxies at these early epochs. If these infant galaxies are numerous, then they could have provided the energy to burn off the fog of hydrogen that blanketed the universe, a process called re-ionization. Re-ionization ultimately made the universe transparent to light.

Read the team’s paper (pdf).

Sources: HubbleSite, ESA Hubble