David Kirkpatrick

August 7, 2010

Beautiful space image — the Antennae galaxies

A space image two-fer today!

Enjoy …

From the link:

The X-ray image from Chandra shows huge clouds of hot, interstellar gas that have been injected with rich deposits of elements from supernova explosions. This enriched gas, which includes elements such as oxygen, iron, magnesium and silicon, will be incorporated into new generations of stars and planets.

The bright, point-like sources in the image are produced by material falling onto black holes and neutron stars that are remnants of the massive stars. Some of these black holes may have masses that are almost one hundred times that of the Sun.

The Spitzer data show infrared light from warm dust clouds that have been heated by newborn stars, with the brightest clouds lying in the overlap region between the two galaxies. The Hubble data reveal old stars in red, filaments of dust in brown and star-forming regions in yellow and white. Many of the fainter objects in the optical image are clusters containing thousands of stars.

July 15, 2010

Is it a planet? Is it a comet? I don’t know!

News from NASA hot from the inbox:

NASA Finds Super Hot Planet With Unique Comet-Like Tail

WASHINGTON, July 15 /PRNewswire-USNewswire/ — Astronomers using NASA’s Hubble Space Telescope have confirmed the existence of a baked object that could be called a “cometary planet.” The gas giant planet, named HD 209458b, is orbiting so close to its star that its heated atmosphere is escaping into space.

Observations taken with Hubble’s Cosmic Origins Spectrograph (COS) suggest powerful stellar winds are sweeping the cast-off atmospheric material behind the scorched planet and shaping it into a comet-like tail.

“Since 2003 scientists have theorized the lost mass is being pushed back into a tail, and they have even calculated what it looks like,” said astronomer Jeffrey Linsky of the University of Colorado in Boulder, leader of the COS study. “We think we have the best observational evidence to support that theory. We have measured gas coming off the planet at specific speeds, some coming toward Earth. The most likely interpretation is that we have measured the velocity of material in a tail.”

The planet, located 153 light years from Earth, weighs slightly less than Jupiter but orbits 100 times closer to its star than the Jovian giant. The roasted planet zips around its star in a short 3.5 days. In contrast, our solar system’s fastest planet, Mercury, orbits the sun in 88 days. The extrasolar planet is one of the most intensely scrutinized, because it is the first of the few known alien worlds that can be seen passing in front of, or transiting, its star. Linsky and his team used COS to analyze the planet’s atmosphere during transiting events.

During a transit, astronomers study the structure and chemical makeup of a planet’s atmosphere by sampling the starlight that passes through it. The dip in starlight because of the planet’s passage, excluding the atmosphere, is very small, only about 1.5 percent. When the atmosphere is added, the dip jumps to 8 percent, indicating a bloated atmosphere.

COS detected the heavy elements carbon and silicon in the planet’s super-hot 2,000 degrees Fahrenheit atmosphere. This detection revealed the parent star is heating the entire atmosphere, dredging up the heavier elements and allowing them to escape the planet.

The COS data also showed the material leaving the planet was not all traveling at the same speed. “We found gas escaping at high velocities, with a large amount of this gas flowing toward us at 22,000 miles per hour,” Linsky said. “This large gas flow is likely gas swept up by the stellar wind to form the comet-like tail trailing the planet.”

Hubble’s newest spectrograph has the ability to probe a planet’s chemistry at ultraviolet wavelengths not accessible to ground-based telescopes. COS is proving to be an important instrument for probing the atmospheres of “hot Jupiters” like HD 209458b.

Another Hubble instrument, the Space Telescope Imaging Spectrograph (STIS), observed the planet in 2003. The STIS data showed an active, evaporating atmosphere, and a comet-tail-like structure was suggested as a possibility. But STIS wasn’t able to obtain the spectroscopic detail necessary to show a tail, or an Earthward-moving component of the gas, during transits. The tail was detected for the first time because of the unique combination of very high ultraviolet sensitivity and good spectral resolution provided by COS.

Although this extreme planet is being roasted by its star, it won’t be destroyed anytime soon. “It will take about a trillion years for the planet to evaporate,” Linsky said.

The results appeared in the July 10 issue of The Astrophysical Journal.

The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center in Greenbelt, Md., manages the telescope. The Space Telescope Science Institute, operated for NASA by the Association of Universities for Research in Astronomy, Inc. in Washington, conducts Hubble science operations.

For illustrations and more information about HD 209458b, visit:

http://www.nasa.gov/hubble

Photo:  http://www.newscom.com/cgi-bin/prnh/20081007/38461LOGO
PRN Photo Desk photodesk@prnewswire.com
http://photos.prnewswire.com/prnh/20081007/38461LOGO
Source: NASA
Web Site:  http://www.nasa.gov/

July 13, 2010

Beautiful space image — NGC 2467

Enjoy

Caption: A colorful star-forming region is featured in this stunning new NASA/ESA Hubble Space Telescope image of NGC 2467. Looking like a roiling cauldron of some exotic cosmic brew, huge clouds of gas and dust are sprinkled with bright blue, hot young stars. Strangely shaped dust clouds, resembling spilled liquids, are silhouetted against a colourful background of glowing. Like the familiar Orion Nebula, NGC 2467 is a huge cloud of gas — mostly hydrogen — that serves as an incubator for new stars. This picture was created from images taken with the Wide Field Channel of the Advanced Camera for Surveys through three different filters (F550M, F660N and F658N, shown in blue, green and red). These filters were selected to let through different colours of red and yellow light arising from different elements in the gas. The total aggregate exposure time was about 2000 seconds and the field of view is about 3.5 arcminutes across. These data were taken in 2004.

Credit: NASA, ESA and Orsola De Marco (Macquarie University)

Usage Restrictions: None

Related news release: Hubble snaps sharp image of cosmic concoction

July 7, 2010

Beautiful space image — NGC 3603

Filed under: et.al., Science — Tags: , , , , — David Kirkpatrick @ 12:45 am

Enjoy

Credit: NASA, ESA, R. O’Connell (University of Virginia), F. Paresce (National Institute for Astrophysics, Bologna, Italy), E. Young (Universities Space Research Association/Ames Research Center), the WFC3 Science Oversight Committee, and the Hubble Heritage Team (STScI/AURA)

From the link:

Most of the stars in the cluster were born around the same time but differ in size, mass, temperature, and color. The course of a star’s life is determined by its mass, so a cluster of a given age will contain stars in various stages of their lives, giving an opportunity for detailed analyses of stellar life cycles. NGC 3603 also contains some of the most  known. These huge stars live fast and die young, burning through their  fuel quickly and ultimately ending their lives in supernova explosions.

And here’s one more from the same group:

Caption: The core of the star cluster in NGC 3603 is shown in great detail in an image from the Wide Field Planetary Camera 2 (WFPC2) camera on the NASA/ESA Hubble Space Telescope. The image is a color composite of observations in the WFPC2 filters F555W (blue), F675W (green) and F814W (red). This view shows the second of two images taken ten years apart that were used to detect the motions of individual stars within the cluster for the first time. The field of view is about 20 arc seconds across.

Credit: NASA, ESA and Wolfgang Brandner (MPIA), Boyke Rochau (MPIA) and Andrea Stolte (University of Cologne)

Usage Restrictions: None

Related news release: Hubble catches stars on the move

April 9, 2010

Beautiful space image — M 66 of the Leo Triplet

Filed under: et.al., Science — Tags: , , , , , , — David Kirkpatrick @ 2:08 am

A gorgeous galaxy:

Click for larger image

Hubble has snapped a spectacular view of M 66, the largest “player” of the Leo Triplet, and a galaxy with an unusual anatomy: it displays asymmetric spiral arms and an apparently displaced core. The peculiar anatomy is most likely caused by the gravitational pull of the other two members of the trio.

The unusual spiral galaxy, Messier 66, is located at a distance of about 35 million light-years in the constellation of Leo. Together with Messier 65 and NGC 3628, Messier 66 is the member of the Leo Triplet, a trio of interacting spiral galaxies, part of the larger Messier 66 group. Messier 66 wins in size over its fellow triplets — it is about 100 000 light-years across.

Be sure to hit the link up there for an absolutely humongous version of the image. Here’s some additional background.

February 2, 2010

Head-on asteroid crash — cool space image

Filed under: Science — Tags: , , , , , — David Kirkpatrick @ 4:33 pm

This bit of interesting news is from this morning’s inbox. Very cool image

Suspected Asteroid Collision Leaves Trailing Debris

WASHINGTON, Feb. 2 /PRNewswire-USNewswire/ — NASA’s Hubble Space Telescope has observed a mysterious X-shaped debris pattern and trailing streamers of dust that suggest a head-on collision between two asteroids. Astronomers have long thought the asteroid belt is being ground down through collisions, but such a smashup has never been seen before.

(Logo:  http://www.newscom.com/cgi-bin/prnh/20081007/38461LOGO)

Asteroid collisions are energetic, with an average impact speed of more than 11,000 miles per hour, or five times faster than a rifle bullet. The comet-like object imaged by Hubble, called P/2010 A2, was first discovered by the Lincoln Near-Earth Asteroid Research, or LINEAR, program sky survey on Jan. 6. New Hubble images taken on Jan. 25 and 29 show a complex X-pattern of filamentary structures near the nucleus.

“This is quite different from the smooth dust envelopes of normal comets,” said principal investigator David Jewitt of the University of California at Los Angeles. “The filaments are made of dust and gravel, presumably recently thrown out of the nucleus. Some are swept back by radiation pressure from sunlight to create straight dust streaks. Embedded in the filaments are co-moving blobs of dust that likely originated from tiny unseen parent bodies.”

Hubble shows the main nucleus of P/2010 A2 lies outside its own halo of dust. This has never been seen before in a comet-like object. The nucleus is estimated to be 460 feet in diameter.

Normal comets fall into the inner regions of the solar system from icy reservoirs in the Kuiper belt and Oort cloud. As comets near the sun and warm up, ice near the surface vaporizes and ejects material from the solid comet nucleus via jets. But P/2010 A2 may have a different origin. It orbits in the warm, inner regions of the asteroid belt where its nearest neighbors are dry rocky bodies lacking volatile materials.

This leaves open the possibility that the complex debris tail is the result of an impact between two bodies, rather than ice simply melting from a parent body.

“If this interpretation is correct, two small and previously unknown asteroids recently collided, creating a shower of debris that is being swept back into a tail from the collision site by the pressure of sunlight,” Jewitt said.

The main nucleus of P/2010 A2 would be the surviving remnant of this so-called hypervelocity collision.

“The filamentary appearance of P/2010 A2 is different from anything seen in Hubble images of normal comets, consistent with the action of a different process,” Jewitt said. An impact origin also would be consistent with the absence of gas in spectra recorded using ground-based telescopes.

The asteroid belt contains abundant evidence of ancient collisions that have shattered precursor bodies into fragments. The orbit of P/2010 A2 is consistent with membership in the Flora asteroid family, produced by collisional shattering more than 100 million years ago. One fragment of that ancient smashup may have struck Earth 65 million years ago, triggering a mass extinction that wiped out the dinosaurs. But, until now, no such asteroid-asteroid collision has been caught “in the act.”

At the time of the Hubble observations, the object was approximately 180 million miles from the sun and 90 million miles from Earth. The Hubble images were recorded with the new Wide Field Camera 3 (WFC3), which is capable of detecting house-sized fragments at the distance of the asteroid belt.

For Hubble images and more information, visit:

http://www.nasa.gov/hubble

Photo:  http://www.newscom.com/cgi-bin/prnh/20081007/38461LOGO
AP Archive:  http://photoarchive.ap.org/
PRN Photo Desk photodesk@prnewswire.com
Source: NASA

Web Site:  http://www.nasa.gov/

And to save a trip to the Hubble site, here’s the image:

Hubble image of comet-like object P/2010 A2

Credit: NASA, ESA, and D. Jewitt (University of California, Los Angeles). Photo No. STScI-2010-07

October 15, 2009

TDRS-1 communications satellite, RIP

Well, technically it isn’t dead — and to get real technical about it, it never was actually alive — but the TDRS-1 communications satellite is being decommissioned after 26 years of circling the Earth working for NASA, scientists, the military and intelligence.

From the link:

Although it was never advertised, the biggest users of the TDRS constellation weren’t NASA astronauts and scientists, but the military and the National Reconnaisance Office, who had priority use of the system for keeping in touch with their spy satellites. This occaisonally caused frustration for scientific users of the system, especially during tense geopolitical moments–in his book on the Hubble Space Telescope, The Hubble WarsEric Chaisson writes about the difficulty of scheduling telescope observations during the first Gulf War.

May 21, 2009

NASA plans robotic moon exploration

A release hot from the inbox:

NASA Details Plans for Lunar Exploration Robotic Missions

WASHINGTON, May 21 /PRNewswire-USNewswire/ — NASA’s return to the moon will get a boost in June with the launch of two satellites that will return a wealth of data about Earth’s nearest neighbor. On Thursday, the agency outlined the upcoming missions of the Lunar Reconnaissance Orbiter, or LRO, and the Lunar Crater Observation and Sensing Satellite, or LCROSS. The spacecraft will launch together June 17 aboard an Atlas V rocket from Cape Canaveral Air Force Station in Florida.

(Logo: http://www.newscom.com/cgi-bin/prnh/20081007/38461LOGO )

Using a suite of seven instruments, LRO will help identify safe landing sites for future human explorers, locate potential resources, characterize the radiation environment and test new technology. LCROSS will seek a definitive answer about the presence of water ice at the lunar poles. LCROSS will use the spent second stage Atlas Centaur rocket in an unprecedented way that will culminate with two spectacular impacts on the moon’s surface.

“These two missions will provide exciting new information about the moon, our nearest neighbor,” said Doug Cooke, associate administrator of NASA’s Exploration Systems Mission Directorate in Washington. “Imaging will show dramatic landscapes and areas of interest down to one-meter resolution. The data also will provide information about potential new uses of the moon. These teams have done a tremendous job designing and building these two spacecraft.”

LRO’s instruments will help scientists compile high resolution, three-dimensional maps of the lunar surface and also survey it in the far ultraviolet spectrum. The satellite’s instruments will help explain how the lunar radiation environment may affect humans and measure radiation absorption with a plastic that is like human tissue.

LRO’s instruments also will allow scientists to explore the moon’s deepest craters, look beneath its surface for clues to the location of water ice, and identify and explore both permanently lit and permanently shadowed regions. High resolution imagery from its camera will help identify landing sites and characterize the moon’s topography and composition. A miniaturized radar will image the poles and test the system’s communications capabilities.

“LRO is an amazingly sophisticated spacecraft,” said Craig Tooley, LRO project manager at NASA’s Goddard Space Flight Center in Greenbelt, Md. “Its suite of instruments will work in concert to send us data in areas where we’ve been hungry for information for years.”

While most Centaurs complete their work after boosting payloads out of Earth’s orbit, the LCROSS Centaur will journey with the spacecraft for four months and be guided to an impact in a permanently shadowed crater at one of the moon’s poles. The resulting debris plume is expected to rise more than six miles. It presents a dynamic observation target for LCROSS as well as a network of ground-based telescopes, LRO, and possibly the Hubble Space Telescope. Observers will search for evidence of water ice by examining the plume in direct sunlight. LCROSS also will increase knowledge of the mineralogical makeup of some of the remote polar craters that sunlight never reaches. The satellite represents a new generation of fast development, cost capped missions that use flight proven hardware and off the shelf software to achieve focused mission goals.

“We look forward to engaging a wide cross section of the public in LCROSS’ spectacular arrival at the moon and search for water ice,” said LCROSS Project Manager Dan Andrews of NASA’s Ames Research Center at Moffett Field, Calif. “It’s possible we’ll learn the answer to what is increasingly one of planetary science’s most intriguing questions.”

LRO and LCROSS are the first missions launched by the Exploration Systems Mission Directorate. Their data will be used to advance goals of future human exploration of the solar system. LRO will spend at least one year in low polar orbit around the moon, collecting detailed information for exploration purposes before being transferred to NASA’s Science Mission Directorate to continue collecting additional scientific data.

Goddard manages the Lunar Reconnaissance Orbiter. Ames manages the Lunar Crater Observation and Sensing Satellite. LRO is a NASA mission with international participation from the Institute for Space Research in Moscow. Russia provides the neutron detector aboard the spacecraft. Northrop Grumman in Redondo Beach, Calif., built the LCROSS spacecraft.

  For more information about LRO, visit:

  http://www.nasa.gov/lro

  For more information about LCROSS, visit:

  http://www.nasa.gov/lcross

Photo:  http://www.newscom.com/cgi-bin/prnh/20081007/38461LOGO
AP Archive:  http://photoarchive.ap.org/
PRN Photo Desk photodesk@prnewswire.com
Source: NASA
   

Web Site:  http://www.nasa.gov/

February 12, 2009

Satellite collision over Siberia

Wow. I bet we see more of this as space becomes more cluttered. We may end up cutting ourselves off from space travel simply by filling the geoorbit with inert space trash.

From the link:

Two big communications satellites collided in the first-ever crash of two intact spacecraft in orbit, shooting out a pair of massive debris clouds and posing a slight risk to the international space station.

NASA said it will take weeks to determine the full magnitude of the crash, which occurred nearly 500 miles over Siberia on Tuesday.

“We knew this was going to happen eventually,” said Mark Matney, an orbital debris scientist at Johnson Space Center in Houston.

NASA believes any risk to the space station and its three astronauts is low. It orbits about 270 miles below the collision course. There also should be no danger to the space shuttle set to launch with seven astronauts on Feb. 22, officials said, but that will be re-evaluated in the coming days.

The collision involved an Iridium commercial satellite, which was launched in 1997, and a Russian satellite launched in 1993 and believed to be nonfunctioning. The Russian satellite was out of control, Matney said.

The Iridium craft weighed 1,235 pounds, and the Russian craft nearly a ton.

Here’s a few space junk facts from the article:

  • At the beginning of this year there were roughly 17,000 pieces of manmade debris orbiting Earth
  • From this collision — As for pieces the size of micrometers, the count will likely be in the thousands
  • Litter in orbit has increased in recent years, in part because of the deliberate breakups of old satellites.
  • Iridium satellites are unusual because their orbit is so low and they move so fast.

December 10, 2008

CO2 on extrasolar planet

Exciting news in the search for life beyond our atmosphere.

The release:

Hubble finds carbon dioxide on an extrasolar planet

The NASA/ESA Hubble Space Telescope’s international team of researchers has discovered carbon dioxide in the atmosphere of a planet orbiting another star. This is an important step along the trail of finding the chemical biotracers of extraterrestrial life, as we know it. These findings have been published in the Astrophysical Journal Letters, 9 December 2008.

The Jupiter-sized planet, called HD 189733b, is too hot for life. But new Hubble observations are a proof-of-concept demonstration that the basic chemistry for life can be measured on planets orbiting other stars. Organic compounds can also be a by-product of life processes and their detection on an Earth-like planet may someday provide the first evidence of life beyond Earth.

Previous observations of HD 189733b by Hubble and the Spitzer Space Telescope found water vapour. Earlier this year Hubble found methane in the planet’s atmosphere.

“This is exciting because Hubble is allowing us to see molecules that probe the conditions, chemistry, and composition of atmospheres on other planets,” says Mark Swain of The Jet Propulsion Laboratory in Pasadena, USA. “Thanks to Hubble we’re entering an era where we are rapidly going to expand the number of molecules we know about on other planets.”

Swain and team used Hubble’s Near Infrared Camera and Multi-Object Spectrometer (NICMOS) to study infrared light emitted from the planet, which lies 63 light-years away. Gases in the planet’s atmosphere absorb certain wavelengths of light from the planet’s hot glowing interior. They identified not only carbon dioxide, but also carbon monoxide. The molecules leave their own unique spectral fingerprint on the radiation from the planet that reaches Earth. This is the first time a near-infrared emission spectrum has been obtained for an extrasolar planet.

“The carbon dioxide is kind of the main focus of the excitement, because that is a molecule that under the right circumstances could have a connection to biological activity as it does on Earth,” Swain says. “The very fact that we’re able to detect it, and estimate its abundance, is significant for the long-term effort of characterizing planets both to find out what they’re made of and to find out if they could be a possible host for life.”

Co-researcher, the UK’s Dr Giovanna Tinetti of the University College London, who holds a prestigious Aurora Fellowship at the Science and Technology Facilities Council (STFC) says: “In the terrestrial planets of our solar system, CO2 plays a crucial role in the stability of climate. On Earth, CO2 is one of the ingredients of the photosynthesis and a key element for the carbon cycle. Our observations represent a great opportunity to understand the role of CO2 in the atmospheres of hot-gaseous and highly irradiated planets”.

This type of observation is best done for planets with orbits tilted edge-on to Earth. They routinely pass in front of and then behind their parent stars, phenomena known as eclipses. The planet HD 189733b passes behind its companion star once every 2.2 days. This allows an opportunity to subtract the light of the star alone (when the planet is blocked) from that of the star and planet together prior to eclipse), thus isolating the emission of the planet alone and making possible a chemical analysis of its “day-side” atmosphere.

In this way, Swain explains that he’s using the eclipse of the planet behind the star to probe the planet’s day side, which contains the hottest portions of its atmosphere. “We’re starting to find the molecules and to figure out how many of them there are to see the changes between the day side and the night side,” Swain says.

This successful demonstration of looking at near-infrared light emitted from a planet is very encouraging for astronomers planning to use the NASA/ESA/CSA James Webb Space Telescope when it is launched in 2013. These biomarkers are best seen at near-infrared wavelengths.

Astronomers look forward to using JWST to spectroscopically look for biomarkers on a terrestrial planet the size of Earth, or a “super-Earth” several times our planet’s mass. “The Webb telescope should be able to make much more sensitive measurements of these primary and secondary eclipse events,” Swain says.

Swain next plans to search for molecules in the atmospheres of other extrasolar planets, as well as trying to increase the number of molecules detected in extrasolar planet atmospheres. He also plans to use molecules to study changes that may be present in extrasolar planet atmospheres to learn something about the weather on these distant worlds.

 

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November 13, 2008

Hubble directly sees extrasolar planet

Sorry about the release dump today, but I haven’t done one in a while and this just hit the inbox and was way, way too cool to pass up passing it along.

The release:

Hubble Directly Observes A Planet Orbiting Another Star

WASHINGTON, Nov. 13 /PRNewswire-USNewswire/ — NASA’s Hubble Space Telescope has taken the first visible-light snapshot of a planet circling another star.

(Logo: http://www.newscom.com/cgi-bin/prnh/20081007/38461LOGO)

Estimated to be no more than three times Jupiter’s mass, the planet, called Fomalhaut b, orbits the bright southern star Fomalhaut, located 25 light-years away in the constellation Piscis Australis, or the “Southern Fish.”

Fomalhaut has been a candidate for planet hunting ever since an excess of dust was discovered around the star in the early 1980s by NASA’s Infrared Astronomy Satellite, IRAS.

In 2004, the coronagraph in the High Resolution Camera on Hubble’s Advanced Camera for Surveys produced the first-ever resolved visible-light image of the region around Fomalhaut. It clearly showed a ring of protoplanetary debris approximately 21.5 billion miles across and having a sharp inner edge.

This large debris disk is similar to the Kuiper Belt, which encircles the solar system and contains a range of icy bodies from dust grains to objects the size of dwarf planets, such as Pluto.

Hubble astronomer Paul Kalas, of the University of California at Berkeley, and team members proposed in 2005 that the ring was being gravitationally modified by a planet lying between the star and the ring’s inner edge.

Circumstantial evidence came from Hubble’s confirmation that the ring is offset from the center of the star. The sharp inner edge of the ring is also consistent with the presence of a planet that gravitationally “shepherds” ring particles. Independent researchers have subsequently reached similar conclusions.

Now, Hubble has actually photographed a point source of light lying 1.8 billion miles inside the ring’s inner edge. The results are being reported in the November 14 issue of Science magazine.

“Our Hubble observations were incredibly demanding. Fomalhaut b is 1 billion times fainter than the star. We began this program in 2001, and our persistence finally paid off,” Kalas says.

“Fomalhaut is the gift that keeps on giving. Following the unexpected discovery of its dust ring, we have now found an exoplanet at a location suggested by analysis of the dust ring’s shape. The lesson for exoplanet hunters is ‘follow the dust,'” said team member Mark Clampin of NASA’s Goddard Space Flight Center in Greenbelt, Md.

Observations taken 21 months apart by Hubble’s Advanced Camera for Surveys’ coronagraph show that the object is moving along a path around the star, and is therefore gravitationally bound to it. The planet is 10.7 billion miles from the star, or about 10 times the distance of the planet Saturn from our sun.

The planet is brighter than expected for an object of three Jupiter masses. One possibility is that it has a Saturn-like ring of ice and dust reflecting starlight. The ring might eventually coalesce to form moons. The ring’s estimated size is comparable to the region around Jupiter and its four largest orbiting satellites.

Kalas and his team first used Hubble to photograph Fomalhaut in 2004, and made the unexpected discovery of its debris disk, which scatters Fomalhaut’s starlight. At the time they noted a few bright sources in the image as planet candidates. A follow-up image in 2006 showed that one of the objects is moving through space with Fomalhaut but changed position relative to the ring since the 2004 exposure. The amount of displacement between the two exposures corresponds to an 872-year-long orbit as calculated from Kepler’s laws of planetary motion.

Future observations will attempt to see the planet in infrared light and will look for evidence of water vapor clouds in the atmosphere. This would yield clues to the evolution of a comparatively newborn 100-million-year-old planet. Astrometric measurements of the planet’s orbit will provide enough precision to yield an accurate mass.

NASA’s James Webb Space Telescope, scheduled to launch in 2013 will be able to make coronagraphic observations of Fomalhaut in the near- and mid-infrared. Webb will be able to hunt for other planets in the system and probe the region interior to the dust ring for structures such as an inner asteroid belt. For more information about the Hubble Space Telescope, visit:

http://www.nasa.gov/hubble

Photo:  http://www.newscom.com/cgi-bin/prnh/20081007/38461LOGO
AP Archive:  http://photoarchive.ap.org/
PRN Photo Desk photodesk@prnewswire.com
Source: NASA
   

Web Site:  http://www.nasa.gov/

August 27, 2008

Clash of galactic titans

UC Santa Barbara astronomers used the Hubble and Chandra to discover a collision of galaxy clusters.

From the release:

Collision of galaxy clusters captured by astronomers

(Santa Barbara, Calif.) – Two UC Santa Barbara astronomers are part of a team that has made a stunning discovery using the Hubble Space Telescope and Chandra X-ray Observatory, it was announced today by the National Aeronautics and Space Administration.

The capture of a collision of galaxy clusters was made by a team led by Marusa Bradac, a postdoctoral researcher and Hubble fellow in UCSB’s Department of Physics. The international team also included Tommaso Treu, assistant professor of physics at UCSB.

“It is in our view an important step forward to understanding the properties of the mysterious dark matter,” Bradac said. “Dark matter makes up five times more matter in the universe than ordinary matter. This study confirms that we are dealing with a very different kind of matter, unlike anything that we are made of. And were able to study it in a very powerful collision of two clusters of galaxies.”

Below is the complete text of the press release issued today by NASA.

(Cambridge, Mass.) – A powerful collision of galaxy clusters has been captured with NASA’s Chandra X-ray Observatory and Hubble Space Telescope. Like its famous cousin, the so-called Bullet Cluster, this clash of clusters provides striking evidence for dark matter and insight into its properties.

Like the Bullet Cluster, this newly studied cluster, officially known as MACSJ0025.4-1222, shows a clear separation between dark and ordinary matter. This helps answer a crucial question about whether dark matter interacts with itself in ways other than via gravitational forces.

This finding is important because it independently verifies the results found for the Bullet Cluster in 2006. The new results show the Bullet Cluster is not an exception and that the earlier results were not the product of some unknown error.

Just like the original Bullet Cluster, MACSJ0025 formed after an incredibly energetic collision between two large clusters in almost the plane of the sky. In some ways, MACSJ0025 can be thought of as a prequel to the Bullet Cluster. At its much larger distance of 5.7 billion light years, astronomers are witnessing a collision that occurred long before the Bullet Cluster’s.

Using optical images from Hubble, the team was able to infer the distribution of the total mass – dark and ordinary matter – using a technique known as gravitational lensing (colored in blue). The Chandra data enabled the astronomers to accurately map the position of the ordinary matter, mostly in the form of hot gas, which glows brightly in X-rays (pink).

An important difference between the Bullet Cluster and the new system is that MACSJ0025 does not actually contain a “bullet.” This feature is a dense, X-ray bright core of gas that can be seen moving through the Bullet Cluster. Nonetheless, the amount of energy involved in this mammoth collision is nearly as extreme as that found in the Bullet Cluster.

As the two clusters that formed MACSJ0025 (each almost a whopping million billion times the mass of the Sun) merged at speeds of millions of miles per hour, the hot gas in each cluster collided and slowed down, but the dark matter did not. The separation between the material shown in pink and blue therefore provides direct evidence for dark matter and supports the view that dark matter particles interact with each other only very weakly or not at all, apart from the pull of gravity.

One of the great accomplishments of modern astronomy has been to establish a complete inventory of the matter and energy content of the Universe. The so-called dark matter makes up approximately 23 percent of this content, five times more than the ordinary matter that can be detected by telescopes. The latest results with MACSJ0025 once again confirm these findings.

 

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The international team of astronomers in this study was led by Marusa Bradac of UCSB, and Steve Allen of the Kavli Institute for Particle Astrophysics and Cosmology at Stanford and Stanford Linear Accelerator Center (SLAC). Other collaborators included Tommaso Treu, UCSB; Harald Ebeling, University of Hawaii; Richard Massey, Royal Observatory Edinburgh; R. Glenn Morris, SLAC; and Anja von der Linden, and Douglas Applegate, both of Stanford. Their results will appear in an upcoming issue of The Astrophysical Journal.

Collision of clusters from the Hubble Telescope and Chandra Observatory.

Collision of clusters from the Hubble Telescope and Chandra Observatory.

July 24, 2008

The Hubble finds galaxy cluster lenses

Filed under: Science — Tags: , , , , , , — David Kirkpatrick @ 6:59 pm

This a great press release from NASA and ESA on the latest Hubble Space Telescope news. Hit the link for a weatlth of images, video and additional text formats.

The release:

News Release – heic0814: Lenses galore – Hubble finds large sample of very distant galaxies

 
 24-Jul-2008: New Hubble Space Telescope observations of six spectacular galaxy clusters acting as gravitational lenses have given significant insights into the early stages of the Universe. Scientists have found the largest sample of very distant galaxies seen to date: ten promising candidates thought to lie at a distance of 13 billion light-years (~redshift 7.5). 

By using the gravitational magnification from six massive lensing galaxy clusters, the NASA/ESA Hubble Space Telescope has provided scientists with the largest sample of very distant galaxies seen to date. Some of the newly found magnified objects are dimmer than the faintest ones seen in the legendary Hubble Ultra Deep Field, which is usually considered the deepest image of the Universe.

By combining both visible and near-infrared observations from Hubble’s Advanced Camera for Surveys (ACS) and Near Infrared Camera and Multi-Object Spectrometer (NICMOS), scientists searched for galaxies that are only visible in near-infrared light. They uncovered 10 candidates believed to lie about 13 billion light-years away (a redshift of approximately 7.5), which means that the light gathered was emitted by the stars when the Universe was still very young — a mere 700 million years old.

These candidates could well explain one of the big puzzles plaguing astronomy today. We know that the Universe was reionised within the first 5-600 million years after the Big Bang, but we don’t know if the ionising energy came from a smaller number of big galaxies or a more plentiful population of tiny ones”, said Johan Richard, from the California Institute of Technology. The relatively high number of redshift 7.5 galaxies claimed in this survey suggests that most of the ionising energy was produced by dim and abundant galaxies rather than large, scarce ones.

The challenge for astronomers is that galaxies beyond a distance of 13 billion light-years (past a redshift of 7) are exceedingly faint and are only visible in the near-infrared — just at the limit of what Hubble can observe” explained Jean-Paul Kneib from the Laboratoire d’astrophysique de Marseille. This new result was only made possible with some cosmic assistance in the form of gravitational lensing that magnified the light from the distant galaxies enough for Hubble to detect them. A firm confirmation of their distance was beyond even the capabilities of the 10-meter Keck telescope and must await powerful future ground-based telescopes.

First confirmed in 1979, gravitational lenses were predicted by Albert Einstein’s theory of General Relativity, a theory that allows astronomers to calculate the path of starlight as it moves through curved space-time. According to the theory, the bending of light is brought about by the presence of matter in the Universe, which causes the fabric of space-time to warp and curve.

Gravitational lensing is the result of this warping of spacetime and is mainly detected around very massive galaxy clusters. Due to the gravitational effect of both the cluster’s observable matter and hidden dark matter, the light is bent around the cluster. This bending of light allows the clusters in certain places to act as natural gravitational telescopes that give the light of faint and faraway objects a boost.

Where Earth-bound telescopes fail to detect such faint and distant objects due to the blurring introduced by the Earth’s atmosphere, a combination of Hubble’s location in space and the magnification of the gravitation lenses provides astronomers with a birds-eye view of these elusive objects.

This technique has already been used numerous times by Hubble and has helped astronomers to find and study many of the most distant known galaxies.

 

Notes for editors:

 

The Hubble Space Telescope is a project of international cooperation between ESA and NASA.

Image credit: NASA, ESA and Johan Richard (Caltech, USA)
Acknowledgement: Davide de Martin & James Long (ESA/Hubble)

 

Links:

Wikipedia site explaining Gravitational Lensing
More Hubble discoveries relating to gravitational lenses