Hubble Archives

April 24, 2008December 24, 2015 by Nancy Atkinson

New Hubble Images Reveal Plethora of Interacting Galaxies

59 new images from the Hubble Space Telescope show some very unusual but incredibly spectacular colliding galaxies. Colliding or interacting galaxies are found throughout the Universe, and sometimes these collisions trigger bursts of star formation, or the mergers form new galaxies. The image above shows the aftermath of an encounter between two galaxies, resulting in a ring-shaped galaxy and a long-tailed companion. Officially called Arp 148, it also has the nickname ‘Mayallâ€™s object.’ It is located in the constellation of Ursa Major, the Great Bear, approximately 500 million light-years away. These images are the largest collection from Hubble ever published simultaneously, and they celebrate the 18th anniversary of Hubbleâ€™s launch. And thereâ€™s moreâ€¦.

This is a stunning snapshot of a celestial dance performed by a pair of similar sized galaxies. ESO 77-14 is in the constellation of Indus, the Indian, some 550 million light-years away from Earth. The galaxy on the right has a long, bluish arm while its companion has a shorter, redder arm.

The Hubble Site has a video about colliding galaxies.

For the entire collection of these images see the Hubble site.

Original News Source: ESA press release

February 19, 2008December 26, 2015 by Fraser Cain

Hubble Finds Dozens of Gravitationally Lensed Galaxies

One of the breakthroughs in modern astronomy is the use of gravitational lenses, where a closer galaxy or star focuses the light from a more distant object. The more astronomers look, the more they find these helpful objects, allowing them to peer at objects much further away. The number of known gravitationally-lensed galaxies jumped up today, when astronomers announced another 67 new lenses.

These 67 lenses were part of the COSMOS project; a detailed survey of small region of the sky about the same as 9 times the area of the Moon. Both Earth and space-based telescopes are working together to provide a survey of the sky which is very deep. And one of the key instruments in the project is the Hubble Space Telescope.

One of the big surprises of this survey is just how many lenses turned up in such a small area of the sky. Based on this discovery rate, researchers think that there could be 500,000 similar gravitationally-lenses galaxies out there.

At least 4 of the lenses are Einstein rings. This is a situation where the foreground and background galaxy are lined up so perfectly, the distorted distant galaxy forms a ring around the closer one.

In order to find the lenses, astronomers had to sift through a collection of 2 million candidate galaxies. Then the researchers had to look through each COSMOS image by eye and identify any potentially strong gravitational lenses. Finally, they checked both the foreground and background galaxy to make sure that they’re really two separate objects separated by billions of light years, and not just a strangely shaped galaxy.

Now that the researchers have so many gravitational lenses, they can do some really interesting things. For example, they’ll be able to study the dark matter distribution around the galactic lenses. And they’ll also be able to start accumulating a census of galaxy masses to see if they match predictions.

Original Source: Hubble News Release

February 12, 2008December 26, 2015 by Fraser Cain

Hubble Finds One of the Earliest, Brightest Galaxies in the Universe

By boosting the abilities of Hubble with a gravitational lens telescope provided by nature, astronomers have been able to peer back to the earliest times in the Universe; to see a galaxy just 700 million years after the Big Bang.

The newly forming galaxy (well, it was newly forming 13 billion years ago) is called A1689-zD1, and appears to be undergoing furious levels of star formation. Just a few hundred million years before this, the Universe was in the dark ages, when the Universe’s hydrogen cooled and formed thick clouds of hydrogen. This hydrogen acted like a fog, obscuring everywhere.

Although it’s tremendously powerful, the Hubble Space Telescope wasn’t strong enough to image the galaxy. It took the additional gravity of the nearby Abel 1689 cluster to act as a natural lens and magnify the light coming from A1689-zD1. With this technique, astronomers were able to increase its brightness by a factor of 10.

The hope is that this galaxy will give astronomers valuable insights into the formative years of galaxy birth and evolution. One of these questions is: what ended the dark ages?

“This galaxy presumably is one of the many galaxies that helped end the dark ages,” said astronomer Larry Bradley of Johns Hopkins University in Baltimore, Md., and leader of the study. “Astronomers are fairly certain that high-energy objects such as quasars did not provide enough energy to end the dark ages of the universe. But many young star- forming galaxies may have produced enough energy to end it.”

The studies show that this galaxy is probably a good example of what most galaxies looked like in the early Universe. It’s just a fraction of the mass of the Milky Way, but it has high rates of star formation. Much of this star formation is happening in very tiny regions compared to the size of the final galaxy.

Obviously, with Hubble straining at its limits to see this galaxy at all, it can’t make out individual stars, only knots of the brightest ones. But future telescopes, such as the James Webb Space Telescope, is ideally suited to take a much deeper look at it. It would also make a good target for the Atacama Large Millimeter Array, which will become the most powerful radio telescope in the world when it’s completed in 2012.

Original Source: Hubble News Release

February 5, 2008December 26, 2015 by Fraser Cain

Hubble Sees an Ancient Elliptical Galaxy

As galaxies come together through successive mergers they take on the splendid spiral shape like our own Milky Way. Keep merging those larger galaxies, though, and you’ll eventually get an elliptical galaxy – a gigantic diffuse cloud of ancient stars with little structure. Such a galaxy, NGC 1132, was recently photographed by the Hubble Space Telescope.

The elliptical galaxy NGC 1132 belongs in this class of galaxies called “giant ellipticals”. And the galaxy, with its constellation of dwarf galaxies is known as a “fossil group”. They’re the remnants and wreckage from past collisions between large galaxies.

In visible light, NGC 1132 looks like a single, isolated galaxy. But using a technique called gravitational lensing to map out the surrounding dark matter, astronomers found that it resides in a huge cloud of the stuff. In fact, NGC 1132 has as much dark matter as you might find in a group of tens or even hundreds of galaxies.

And once again, in visible light, its stars extend 120,000 light years from its centre. But in the X-ray spectrum, the glow extends 10 times as far – again, similar to a group of galaxies.

So where do fossil groups like this come from? Astronomers think they’re the end product of cosmic collisions, where a single large galaxy consumes all of its neighbors. It’s also possible they’re the result of a strange process, where something stopped moderate galaxies from forming, and only a single large galaxy came together in that region of space.

By analyzing galaxies like this, astronomers will get a better sense of galaxy evolution. It’ll help predict what’s going to happen when the Milky Way and Andromeda collide billions of years in the future.

Original Source: ESA/Hubble News Release

January 10, 2008December 26, 2015 by Fraser Cain

Supercluster Ruled By the Pull of Dark Matter

Enough of this small stuff, let’s look at the big picture. The really really big picture. In this case, one of the largest patches of the sky ever observed by the Hubble Space Telescope. A new detailed survey was released today that combines 80 separate Hubble images together. In addition to a framework of galaxy clusters, the images show the distribution of dark matter that holds the clusters together – and tears it all apart.

The dark matter survey is part of the Space Telescope Abell 901/902 Galaxy Evolution Survey (STAGES), which looks at one of the larger structures in the Universe: the Abell 901/902 superclusters. This is a region of tremendous violence and chaos. Galaxies are being pulled into the core of the superclusters, and getting distorted and stripped of their gas and dust.

And one of the primary forces of this violence comes from the completely invisible dark matter that makes up the bulk of the matter in the region. Instead of being equally distributed, though, this dark matter has pooled into enormous clumps.

An international team of astronomers used Hubble to measure how individual galaxies are distorted by clouds of dark matter. The dark matter is invisible, but it does have mass, which can pull at the light as it moves past. The astronomers know what different galaxies should probably look like, and then can figure out how much dark matter is in between, distorting the view. It’s actually pretty incredible to see the dark matter map imposed over top of the visible light image.

“Thanks to Hubble’s Advanced Camera for Surveys, we are detcting for the first time the irregular clumps of dark matter in this supercluster,” said Catherine Heymans of the University of British Columbia. “We can even see an extension of the dark matter toward a very hot group of galaxies that are emitting X-rays as they fall into the densest cluster core.”

The Hubble study identified 4 separate regions where the dark matter has pooled into dense clumps, adding up to 100 trillion times the mass of the Sun. They can even make out irregular clumps of dark matter in the supercluster. These areas match the locations where hundreds of old galaxies have already experienced the violent passage from the outskirts of the supercluster into the denser regions.

Original Source: Hubble News Release

January 8, 2008December 26, 2015 by Fraser Cain

The Plan to Fix Hubble

Although the space shuttles have a busy schedule completing the construction of the International Space Station, there’s one other job to complete – servicing the Hubble Space Telescope. NASA officials announced the details of the mission today at the Winter meeting of the American Astronomical Society. If all goes well, the space shuttle Atlantis will visit Hubble some time around August 2008, carrying 7 astronauts and the spare parts they need to bring Hubble back to top-notch condition.

Over the course of 11 days, the astronauts will perform a total of 5 spacewalks. During these trips to service Hubble, the astronauts will install two new science instruments, upgrade existing instruments and replace failing gyroscopes, batteries and thermal blankets. Atlantis will also reboost the telescope’s decaying orbit.

One of the most critical jobs will be to repair the telescope’s Advanced Camera for Surveys (ACS). This is the visible light instrument that produces the pretty pictures that have made Hubble so famous. The instrument suffered a power failure in January 2007.

With this collection of upgrades, Hubble’s life should be extended to 2013. David Leckrone, Senior Hubble Project Scientist noted that “when the astronauts leave Hubble for the last time, it will be at the apex of its capabilities – better than it has ever been before.” In fact, with these upgrades, Hubble should be 90X more sensitive than before.

One of the unique challenges of this mission will be for the astronauts to repair components that were never designed for orbital repair. In some cases, the astronauts will need to open up boxes and replace circuit boards.

Lead astronaut John Grunsfeld explained just how complex the task of repairing the Advanced Camera for Surveys is going to be, “we’re going to do something that’s never been done before. We’re going to swap circuit boards. We’re going to be working with hundreds of number 4 torque screws. These are really tiny screws. Whatever you do, don’t lose a screw inside the telescope. I have to cut an electromagnetic blanket on the Advanced Cameras for Surveys which could leave sharp edges. We’re astronauts, wearing balloons of air around us, and we don’t like sharp edges. With that removed, I then have to remove 36 of these screws. But they’re at an angle, so I won’t be able to see or reach them easily. I’ve been training in an underwater tank, and plan to get to know each of these screws.”

To demonstrate the tools he’s going to be working with, John Grunsfeld wore his astronaut gloves during his presentation in today’s press conference. “I figured I needed as much practice with these gloves as possible.”

Even the death of Hubble is being arranged. At some point in 2020, when the telescope finally reaches the end of its enhanced lifetime, NASA intends to dock a rocket to the telescope and then drive it into the ocean. As part of this process, the astronauts will install a special docking module, so the deorbiting rocket can attach easily and complete its grim task.

November 29, 2007December 26, 2015 by Fraser Cain

Hubble’s View of M74

During many holidays, the folks working on NASA’s Hubble Space Telescope try and find an image that captures the essence of the celebration. We’ve seen Christmas Tree clusters and spooky nebulae. To show their holiday spirit, the Hubble folks have released this beautiful image of the spiral galaxy M74. It’s a stretch, I guess, but wow, what a picture.

From the original Hubble news release, here’s how they describe the photograph.

Hubble has sent back an early Christmas card with this new NASA/ESA Hubble Space Telescope image of the nearby spiral galaxy Messier 74. It is an enchanting reminder of the impending season. Resembling glittering baubles on a holiday wreath, bright knots of glowing gas light up the spiral arms; regions of new star birth shining in pink.

Messier 74 is one of the best examples we can see of a “grand design” spiral galaxy, much like our own Milky Way. In the case of M74, it’s conveniently facing face on, so we can see intricate details in all parts of the galaxy’s structure.

The bright pink areas in the spiral arms are huge, short lived clouds of hydrogen gas glowing from the newborn stars inside them. The dark dust lanes that extend out along the spiral arms contain a new generation of blue stars.

M74 was first discovered by the French astronomer Pierre Mechain in 1780, and then added to Charles Messier’s famous catalogue of deep sky objects. Of all the objects in the catalogue, it’s one of the faintest, and has been nicknamed “The Phantom Galaxy” by amateur astronomers trying to spot it in their telescopes.

So thanks Hubble, feel free to celebrate any holiday, celebration or random even you like. Just keep the pictures coming.

Original Source: Hubble News Release

November 15, 2007December 26, 2015 by Fraser Cain

Finally, Hubble’s View of Comet Holmes

All right, here’s the picture we’ve all been waiting for. Step aside ground-based observatories, papa Hubble’s here with images of Comet Holmes, which is now larger than the Sun. But don’t get fooled. That beautiful image on the left was taken by amateur astronomer Alan Dyer from Alberta, Canada. Hubble’s version on the right. It’s not as pretty, but it’s got inner bigness.

You already know the story. Comet Holmes was a boring comet out near the orbit of Jupiter when it flared up on October 23rd. The coma of gas and dust expanded away from the comet, and now it extends to a volume larger than the Sun.

Of course, astronomers scrambled to turn the mighty Hubble Space Telescope to join in on the sky show. The space observatory’s Wide Field Planetary Camera 2 monitored the object for several days, capturing images on October 29, 31 and November 4.

The Hubble image on the right reveals the comet’s nucleus down to a resolution as small as 54 km (33 miles) across. The image was processed to reveal differences in dust distribution near the nucleus.

Astronomers found that there’s twice as much dust along the east-west direction as the north-south direction. This gives the comet a bowtie appearance. Even 12 days after the outburst, when this picture was captured, the nucleus is still surrounded by bright dust.

This isn’t the first time that Hubble has viewed Comet Holmes. Luckily, it actually captured an image back in June 15, 1999. Back then, there was no dust around the object, and Hubble couldn’t reveal the nucleus. By measuring its brightness, astronomers estimated that Holmes is approximately 3.4 km (2.1 miles) across.

Once Holmes settles down again, astronomers will use Hubble to make another accurate measurement of its brightness. By calculating the difference, astronomers will be able to figure out how much mass it lost during this outburst.

Original Source: Hubble News Release

October 30, 2007December 26, 2015 by Fraser Cain

Hubble Sees Beautiful Carnage

Ahh, another beautiful photograph captured by the Hubble Space Telescope. This time we’re looking at two big, beautiful spiral galaxies… tearing each other apart. The large, face-on spiral is NGC 3808, while its dueling partner is the smaller, edge-on NGC 3808A. And between the two is a long today tail of stars, gas and dust, transferring from one to the other.

The two galaxies are collectively known as Arp 87; just one of the hundreds of interacting galaxies seen by astronomers. It was cataloged by the famous Halton Arp in the 1960’s, who maintained his Atlas of Peculiar Galaxies. And this collision is plenty peculiar, thanks to Hubble’s optics and resolution of fine details.

A stream of gas, stars and dust is flowing from NGC 3808 to its companion, enveloping it in a starry embrace. Because the NGC 3808A is seen nearly edge-on, you can make out the twisting trail of stars wrapping around it. Both galaxies have been distorted by their gravitational interaction.

When galaxies interact, stars are born. And this is the case for Arp 87. The colour of the stars and the intensity of heated interstellar dust show that both galaxies are undergoing furious rates of star formation.

Original Source: Hubble News Release

October 16, 2007December 26, 2015 by Fraser Cain

Nearby Galaxy is Older Than it Looks

Look at the picture associated with this story. It just looks like a pretty galaxy, right? Well, according to astronomers, it’s actually much older than it appears. This image, captured by the Hubble Space Telescope, provides one of the most detailed observations ever taken of I Zwicky 18 – a galaxy that looks younger than it should.

According to researcher, galaxies like I Zwicky 18 are much more common billions of light years away, at a time when the Universe was much younger than it is today. These baby galaxies still had large quantities of gas and dust they could use up to make new stars. Their young hot stars, composed largely of primordial hydrogen and helium manufactured during the Big Bang, burn brightly in the blue end of the visible light spectrum.

Older galaxies, like our own Milky Way have had plenty of time to use up those primordial elements, mixing in heavier elements with generation after generation of supernovae.

Astronomers used to think that I Zwicky 18 was a rare example of a nearby, newly forming galaxy. Located only 59 million light-years from Earth, this galaxy could be used as a sort of time machine, to see the stages that galaxies went through early on in their evolution.

Well, the new observations from Hubble have dashed those hopes. I Zwicky 18 is old, possibly as old as the Milky Way, forming its first stars up to 10 billion years ago. With its sensitive instruments, Hubble was able to spot previously hidden red, older stars, showing that the galaxy has been forming stars for billions of years.

So how is it possible that such an old galaxy still has large quantities of primordial hydrogen and helium, but we see rapid star formation today? It’s possible that the galaxy has just been going slowly, forming stars at a dramatically reduced rate in the past. But something kicked that rate of star formation into high gear in the recent past.

Original Source: Hubble News Release