samedi 22 décembre 2012

This month in 1991: The web spreads beyond CERN

CERN - European Organization for Nuclear Research logo.

Dec. 22, 2012

Image above: The world's first web server, Tim Berners-Lee's NeXT machine at CERN. The hand-written sticker reads: "This machine is a server. DO NOT POWER DOWN!" (Image: CERN).

Twenty-one years ago this month, physicists at the Stanford Linear Accelerator Center (SLAC) in California installed the first web server outside of Europe. The move marked the beginning of the global reach of the World Wide Web, a key point in the history of digital communications.

Twenty-one years ago this month, physicists at the Stanford Linear Accelerator Center (SLAC) in California installed the first web server outside of Europe. The move marked the beginning of the global reach of the World Wide Web, a key point in the history of digital communications.


Tim Berners-Lee and Robert Cailliau developed the world's first browser,"WorldWideWeb" at CERN in 1990. In November that year, they presented a new coding language called hypertext to CERN colleagues. A month later, Berners-Lee and Cailliau used WorldWideWeb software for the first communication between a web client and a server over the internet. The machine at SLAC used the same software to serve several pages, including a phonebook and preprints of papers on high-energy physics.

Tim Berners-Lee, World Wide Web inventor

Robert Cailliau, World Wide Web inventor

The world's first ever website and server,, ran on a NeXT computer at CERN. The first web page address was, which centred on information regarding the WorldWideWeb project itself. Visitors could learn more about hypertext, technical details for creating their own webpages, and even an explanation on how to search the web for information. There are no screenshots of this original page and, in any case, changes were made daily to the information available on the page as the WorldWideWeb project developed. You may find a later copy, from 1992, on the World Wide Web Consortium website.

The web at CERN grew from include a phonebook, high-energy physics papers, and general information about the experiments at the laboratory. Today CERN hosts over 10,000 websites, helping to keep a global community of physicists connected.


CERN, the European Organization for Nuclear Research, is the world's leading laboratory for particle physics. It has its headquarters in Geneva. At present, its member states are Austria, Belgium, Bulgaria, the Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Italy, the Netherlands, Norway, Poland, Portugal, Slovakia, Spain, Sweden, Switzerland and the United Kingdom. Romania is a candidate for accession. Israel and Serbia are associate members in the pre-stage to membership. India, Japan, the Russian Federation, the United States of America, Turkey, the European Commission and UNESCO have observer status.

Find out more on the new CERN website:

The birth of the World Wide Web:

CERN - European Organization for Nuclear Research website:

Related links:

Stanford Linear Accelerator Center:

World Wide Web Consortium website:

Images, Text, Credits: CERN / Aerospace.

Best regards,

vendredi 21 décembre 2012

Apollo 8: Christmas at the Moon

NASA - Apollo 8 Mission patch / NASA - Lunar Reconnaissance Orbiter (LRO) patch.

Dec. 21, 2012

Christmas Eve, 1968. As one of the most turbulent, tragic years in American history drew to a close, millions around the world were watching and listening as the Apollo 8 astronauts -- Frank Borman, Jim Lovell and Bill Anders -- became the first humans to orbit another world.

Image above: Apollo 8, the first manned mission to the moon, entered lunar orbit on Christmas Eve, Dec. 24, 1968. That evening, the astronauts held a live broadcast from lunar orbit, during which they showed pictures of the Earth and moon as seen from their spacecraft. Image Credit: NASA.

As their command module floated above the lunar surface, the astronauts beamed back images of the moon and Earth and took turns reading from the book of Genesis, closing with a wish for everyone "on the good Earth."

"We were told that on Christmas Eve we would have the largest audience that had ever listened to a human voice," recalled Borman during 40th anniversary celebrations in 2008. "And the only instructions that we got from NASA was to do something appropriate."

"The first ten verses of Genesis is the foundation of many of the world's religions, not just the Christian religion," added Lovell. "There are more people in other religions than the Christian religion around the world, and so this would be appropriate to that and so that's how it came to pass."

The mission was also famous for the iconic "Earthrise" image, snapped by Anders, which would give humankind a new perspective on their home planet. Anders has said that despite all the training and preparation for an exploration of the moon, the astronauts ended up discovering Earth.

NASA's LRO Brings Earthrise to Everyone

Video above: On December 24, 1968, Apollo 8 Commander Frank Borman and crew members William A. Anders and James A. Lovell, Jr. became the first humans to photograph the Earth rising over the moon. Now, the rest of us can see what it was like in a new NASA visualization that draws on richly detailed maps of the moon's surface made from data gathered by NASA's Lunar Reconnaissance Orbiter!

Lunar Reconnaissance Orbiter (LRO)

The Apollo 8 astronauts got where they were that Christmas Eve because of a bold, improvisational call by NASA. With the clock ticking on President Kennedy's challenge to land on the moon by decade's end, delays with the lunar module were threatening to slow the Apollo program. So NASA decided to change mission plans and send the Apollo 8 crew all the way to the moon without a lunar module on the first manned flight of the massive Saturn V rocket.

Apollo 8 - Round the moon and back

The crew rocketed into orbit on December 21, and after circling the moon 10 times on Christmas Eve, it was time to come home. On Christmas morning, mission control waited anxiously for word that Apollo 8's engine burn to leave lunar orbit had worked. They soon got confirmation when Lovell radioed, "Roger, please be informed there is a Santa Claus."

The crew splashed down in the Pacific on December 27. A lunar landing was still months away, but for the first time ever, men from Earth had visited the moon and returned home safely.

Related story:

NASA's Lunar Reconnaissance Orbiter Brings 'Earthrise' to Everyone:

Images, Video, Text, Credit: NASA / GSFC.

Best regards,

Canadian Experiment to Track Space Radiation and Its Risks

ISS - International Space Station patch.

Dec. 21, 2012

Space can be a potentially hazardous environment to live and work in, especially when it comes to radiation. Originating from violent storms on the sun and galactic cosmic rays produced in distant supernovae explosions, this natural radiation can pose a serious health risk for astronauts on long-duration space missions like those on the International Space Station.

Like a protective bubble, Earth's atmosphere and magnetosphere shields life on our planet from this never-ending bombardment of high-energy particles. However, in low-Earth orbit where the space station flies, astronauts are regularly exposed to high doses of radiation, including charged particles trapped in Earth's magnetic field, as well as cosmic rays and solar radiation.

NASA SDO - Filament Eruption August 31, 2012

Video above: Solar storms, like this coronal mass ejection on Aug. 31, 2012, can propel a billion tons of charged particles and radiation into space. Occasionally, these eruptions are directed towards Earth, prompting special protective measures for astronauts aboard the International Space Station, as well as aircraft crew on transpolar flights where risk to exposure is greatest. (NASA SDO).

To prepare for future missions that may last for months or years, the Canadian Space Agency, or CSA, along with other space agencies around the world, have been stepping up research into radiation biology in recent years, recognizing that it deserves the highest priority.

International Space Station (ISS)

During CSA astronaut Chris Hadfield's mission to the space station, he will carry a new set of instruments into orbit to measure one of the most serious types of radiation -- caused by high-energy neutron particles -- and monitor the dose an astronaut absorbs during space flight.

What is Neutron Radiation?

Neutron radiation is considered to be one of the most severe of all types of radiation experienced in space as it can cause biological damage. It represents approximately 30 percent of the total exposure for those aboard the station. In space, neutrons are produced when charged particles collide with physical matter, such as the walls and equipment on the space station. Just like medical X-rays, these high-energy particles can shoot through delicate body tissues, and through long-term exposure, they can damage DNA and potentially cause cataracts, bone marrow damage or even cancer.

It's all in the bubbles -- Bubbles and Radiation Trouble

Radi-N2 is Canada's second generation of neutron radiation monitoring aboard the station and continues on where fellow Canadian astronaut Robert Thirsk and the original Radi-N experiment left off in 2009.

A collaborative effort between the CSA and Russia's RSC-Energia and State Research Center of Russia Institute of Biomedical Problems, or IBMP, Russian Academy of Sciences, the Radi-N2 study will have Hadfield and fellow crew member Roman Romanenko measure the neutron radiation levels on the station while onboard the station for Expedition 34/35.

Image above: Radi-N2 bubble detectors are filled with a gel, inside which are liquid droplets that help quantify neutron radiation inside the International Space Station. (Canadian Space Agency).

Radi-N2 uses bubble detectors produced by a Canadian company, Bubble Technology Industries of Chalk River, Ontario, designed to focus on detecting neutrons while ignoring other types of radiation. Bubble detectors have been used in space for more than two decades on space shuttle missions and the MIR space station, and have become popular because of their accuracy and convenience.

Eight of these finger-sized instruments are going to be placed by Hadfield and Romanenko around various space station modules. Each detector is filled with a clear polymer gel, inside which are liquid droplets. When a neutron strikes the test tube, a droplet may be vaporized. This creates a visible gas bubble in the polymer. Each bubble, which represents neutron radiation, is then placed within an automatic reader and counted.

Radi-N2 will provide critical information for potential future human missions to the moon, asteroids and eventually Mars.

CSA's support of radiation research will not only lead to major advancements for future human exploration of space but also in our knowledge of the health risks of radiation, such as cancer, neurological damage and degenerative tissue disease.

This original story was written and published by the Canadian Space Agency on Dec. 12, 2012. Date modified:

Related links:

Radi-N2 Experiment:

Chris Hadfield's mission to the space station:

Canadian Space Agency:

International Space Station:

Images, Video, Text, Credits: NASA / SDO / CSA-ASC.


Hubble Eyes the Needle Galaxy

NASA - Hubble Space Telescope patch.

Dec. 21, 2012

Like finding a silver needle in the haystack of space, the NASA/ESA Hubble Space Telescope has produced this beautiful image of the spiral galaxy IC 2233, one of the flattest galaxies known.

Typical spiral galaxies like the Milky Way are usually made up of three principal visible components: the disk where the spiral arms and most of the gas and dust is concentrated; the halo, a rough and sparse sphere around the disk that contains little gas, dust or star formation; and the central bulge at the heart of the disk, which is formed by a large concentration of ancient stars surrounding the Galactic Center.

However, IC 2233 is far from being typical. This object is a prime example of a super-thin galaxy, where the galaxy’s diameter is at least ten times larger than the thickness. These galaxies consist of a simple disk of stars when seen edge on. This orientation makes them fascinating to study, giving another perspective on spiral galaxies. An important characteristic of this type of objects is that they have a low brightness and almost all of them have no bulge at all.

Hubble Space Telescope

The bluish color that can be seen along the disk gives evidence of the spiral nature of the galaxy, indicating the presence of hot, luminous, young stars, born out of clouds of interstellar gas. In addition, unlike typical spirals, IC 2233 shows no well-defined dust lane. Only a few small patchy regions can be identified in the inner regions both above and below the galaxy’s mid-plane.

Lying in the constellation of Lynx, IC 2233 is located about 40 million light-years away from Earth. This galaxy was discovered by British astronomer Isaac Roberts in 1894.

This image was taken with the Hubble’s Advanced Camera for Surveys, combining visible and infrared exposures. The field of view in this image is approximately 3.4 by 3.4 arcminutes.


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

ESA Hubble website:

NASA Hubble website:

Images, Text, Credits: ESA / Hubble & NASA.


Manned transport spacecraft Soyuz TMA-07M docked to the ISS

ROSCOSMOS - Soyuz TMA07M Mission patch.


December 21, 18 hours 08 minutes MSK manned transport spacecraft "Soyuz TMA-07M", was successfully launched on December 19 from the Baikonur Cosmodrome, automatically docked with the research module Rassvet at 9:09 a.m. EST on Friday after spending two days in orbit.

Soyuz TMA07M arrival at the Station

After checking airtightness between the spacecraft and the module will open passageways. After that, the ISS crew will TPK "Soyuz TMA-07M" in the Roman Romanenko (Roscosmos), Chris Hadfield (Canadian Space Agency) and Thomas Marshburn (NASA). They will join the crew at the station as part of the ISS Commander Kevin Ford, flight engineer Oleg Novitsky and Eugene Tarelkin.

Soyuz TMA-07M docking ISS

After opening the hatch room main mission will change to 34/35, and the crew will consist of six members.

 Image above: The six-member Expedition 34 crew participates in a welcome ceremony with family members and mission officials. Credit: NASA TV.

The expedition will continue to carry out experiments in space biotechnology, biomedical research, remote sensing of the Earth, solar system exploration, space material science, geophysics and exploration of near space, as well as education and development of the technology.

Artist's view of the docking of  the Soyuz TMA at the Space Station

According to the flight program scheduled to run programs for scientific and applied research and experimentation, spacewalk, working with cargo spacecraft "Progress M-16M", "Progress M-17M", "Progress M-18M", "Progress M- 19M "as well as with European cargo spacecraft ATV4.

All crew members TPK "Soyuz TMA-07M" have the experience of space flight to the International Space Station. Roman Romanenko completed his first space flight from May 27 to December 1, 2009 as the commander of the WPK "Soyuz TMA-15" and ISS flight engineer. Chris Hadfield performed two space flights: from 12 to 20 November 1995 as a specialist one in the crew STS-74 and from April 19 to May 1, 2001 as a Mission Specialist-1 in the crew of STS-100. In the space career Thomas Marshburn one space mission from 15 to 31 July 2009 as a specialist in the crew of STS-127.

Original text in Russian:

Read more about Expedition 34 (NASA):

Send a holiday postcard to the station crew:

Images, Video, Text, Credits: Press Service of the Russian Federal Space Agency (Roscosmos PAO) / ROSCOSMOS / ROSCOSMOS TV / NASA / NASA TV / Translation: Aerospace.


Cryosat Hits Land

ESA - CRYOSAT Mission logo.

21 December 2012

ESA’s ice mission is now giving scientists a closer look at oceans, coastal areas, inland water bodies and even land, reaching above and beyond its original objectives.

Launched in 2010, the polar-orbiting CryoSat was developed to measure the changes in the thickness of polar sea ice, the elevation of the ice sheets that blanket Greenland and Antarctica, and mountain glaciers.

Altimeter reading over Cuba

The satellite’s radar altimeter not only detects tiny variations in the height of the ice, it also measures sea level and the sea ice’s height above water to derive sea-ice thickness with an unprecedented accuracy.

At a higher precision than previous altimeters, CryoSat’s measurements of sea level are improving the quality of the model forecasts. Small, local phenomena in the ocean surface like eddies can be detected and analysed.

300 m resolution

Taking CryoSat a step further, scientists have now discovered that the altimetry readings have the potential to map sea level closer to the coast, and even greater capabilities to profile land surfaces and inland water targets such as small lakes, rivers and their intricate tributaries.

Radar altimeters have more difficulty doing this because, compared to open ocean measurements, the landscape surrounding inland water bodies is a lot more complex.

These had not been previously monitored with satisfying accuracy by conventional altimeters because the sensor footprints – about 5x5 km – were too large to detect subtle differences in the topography around small landforms.

CryoSat, however, has a resolution along its ground track of about 300 m.

In order to thoroughly investigate the possibilities offered by CryoSat over water, ESA recently began scientific exploitation projects coined ‘CryoSat+’.

Readings over Danube River delta

Scientists are reprocessing large, raw and uncompressed sets of data coming directly from CryoSat to obtain new information on oceans, inland water bodies and land.

In the example pictured above, CryoSat’s altimeter made readings over central Cuba, extending north and south into the surrounding water.

The image clearly shows the difference between the bright radar reflections from the steady water and the elevated land.

For instance, near the edges of the island, points of high radar reflection are pictured in red. This is due to the more placid waters of the bay and over coral reefs.

Examples are also pictured over the Danube delta in eastern Romania, and the land-locked Issyk Kul lake in Kyrgyzstan.

Altimeter readings over Issyk Kul

“Thanks to CryoSat being operated over some inland water targets in high resolution mode, we were able to distinctly chart the contours of a flood that occurred last March at Rio Negro in the Amazon,” said Salvatore Dinardo, working for ESA on CryoSat+.

Jérôme Benveniste, the ESA scientist who initiated the project, continued, “We were able to emphasise the unique capability to see the floodwater extent under the forest canopy, where optical sensors or even imaging radars are blocked by the trees.”

CryoSat seen from underneath

Results from the project will be unveiled to the scientific community at the Third CryoSat User Workshop to be held in Germany at the Technical University of Dresden on 12–14 March.

Related links:

Third CryoSat User Workshop:

Access CryoSat data:

Images, Text, Credits: ESA.

Best regards,

mercredi 19 décembre 2012

Successful launch for Ariane 5 ECA, Flight VA211

ESA / ARIANESPACE Flight VA211 poster.

Dec. 19, 2012

 Ariane 5 ECA launch with Skynet 5D and Mexsat Bicentenario satellite passengers

Successful launch for Ariane 5 ECA tonight at 21:49 GMT (22:49 CET; 18:49 French Guiana). Arianespace’s Ariane 5 flight with the Skynet 5D and Mexsat Bicentenario satellite passengers tonight wrapped up another busy year of company launch activity, with its successes highlighted by the theme of “10.”

Launch of the Ariane Flight VA211

Video above: Launch of Mexsat-3 Bincentenario and Skynet-5D satellites with an Ariane 5 rocket (flight VA211) from French Guiana's Arianespace Spaceport.

Built by Astrium, Skynet 5D weighed approximately 4,800 kg. at launch, and is the fourth for the British military’s Skynet 5 satellite system.  This spacecraft is designed to reinforce and extend the operational services provided by the three other Skynet 5 satellites – all orbited by Ariane 5 – and will be located over the Middle East at a 53 deg. East orbital slot.  The Skynet program is operated as a Private Finance Initiative with the United Kingdom’s Ministry of Defence.

Skynet 5D satellite

Mexsat Bicentenario weighed an estimated 2,935 kg. for liftoff, and is based on Orbital Sciences Corporation’s GEOStar-2 platform.  It is to provide communications services to Mexico and its surrounding waters from the 114.9 deg. West Longitude orbital slot. Orbital was designated by Boeing to provide the Fixed Satellite Services (FSS) segment of the Mexsat satellite system for the Federal Government of Mexico.

Mexsat Bicentenario satellite

As Arianespace celebrated a 2012 to remember in terms of its launch activity, the company already is looking to next year’s activity – with preparations well advanced for an Ariane 5 launch in February, which is to orbit the Amazonas 3 and Azerspace/Africasat-1 telecommunications satellites.

Related links:

Astrium website:

Astrium Services website:

Federal Government of Mexico - Ministry of Communications and Transportation website:


Images, Video, Text, Credits: ESA / Arianespace / Arianespace TV / Astrium / Boeing / Catherine Laplace-Builhe / Aerospace.

Best regards,

Curiosity Rover Explores 'Yellowknife Bay'

NASA - Mars Science Laboratory (MSL) patch.

Dec. 19, 2012

Image above: The NASA Mars rover Curiosity used its left Navigation Camera to record this view of the step down into a shallow depression called "Yellowknife Bay." Image credit: NASA/JPL-Caltech.

The NASA Mars rover Curiosity this week is driving within a shallow depression called "Yellowknife Bay," providing information to help researchers choose a rock to drill.

Using Curiosity's percussive drill to collect a sample from the interior of a rock, a feat never before attempted on Mars, is the mission's priority for early 2013. After the powdered-rock sample is sieved and portioned by a sample-processing mechanism on the rover's arm, it will be analyzed by instruments inside Curiosity.

Yellowknife Bay is within a different type of terrain from what the rover has traversed since landing inside Mars' Gale Crater on Aug. 5, PDT (Aug. 6, UTC). The terrain Curiosity has entered is one of three types that intersect at a location dubbed "Glenelg," chosen as an interim destination about two weeks after the landing.

This map traces where NASA's Mars rover Curiosity drove between landing at a site subsequently named "Bradbury Landing," and the position reached during the mission's 130th Martian day, or sol, (Dec. 17, 2012). Image credit: NASA/JPL-Caltech/Univ. of Arizona.

Curiosity reached the lip of a 2-foot (half-meter) descent into Yellowknife Bay with a 46-foot (14-meter) drive on Dec. 11. The next day, a drive of about 86 feet (26.1 meters) brought the rover well inside the basin. The team has been employing the Mast Camera (Mastcam) and the laser-wielding Chemistry and Camera (ChemCam) for remote-sensing studies of rocks along the way.

On Dec. 14, Curiosity drove about 108 feet (32.8 meters) to reach rock targets of interest called "Costello" and "Flaherty." Researchers used the Alpha Particle X-Ray Spectrometer (APXS) and Mars Hand Lens Imager (MAHLI) at the end of the rover's arm to examine the targets. After finishing those studies, the rover drove again on Dec. 17, traveling about 18 feet (5.6 meters) farther into Yellowknife Bay. That brings the mission's total driving distance to 0.42 mile (677 meters) since Curiosity's landing.

Curiosity Self-Portrait, Wide View. Image credit: NASA/JPL-Caltech/MSSS

One additional drive is planned this week before the rover team gets a holiday break. Curiosity will continue studying the Martian environment from its holiday location at the end point of that drive within Yellowknife Bay. The mission's plans for most of 2013 center on driving toward the primary science destination, a 3-mile-high (5-kilometer) layered mound called Mount Sharp.

How Do Rovers Drive on Mars?

How Do Rovers Drive on Mars?

The 'keys' to NASA's Mars rovers are in the capable hands of the official rover drivers. Learn how they operate the vehicles from millions of miles away in this 60-second video from NASA's Jet Propulsion Laboratory. Credit: NASA/JPL-Caltech.

NASA's Mars Science Laboratory Project is using Curiosity during a two-year prime mission to assess whether areas inside Gale Crater ever offered a habitable environment for microbes. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the project for NASA's Science Mission Directorate in Washington.

More information about Curiosity is online at and . You can follow the mission on Facebook at: and on Twitter at:

Curiosity gallery:

Images (mentioned), Video (mentioned), Text, Credits: NASA / JPL / Guy Webster.


How to look young when you're not

ESA - Hubble Space Telescope logo / ESO - European Southern Observatory logo.

19 December 2012

Stars reveal the secret of aging well

 The globular cluster NGC 6388, observed by Hubble

Some people are in great shape at the age of 90, while others are decrepit before they’re 50. We know that how fast people age is only loosely linked to how old they actually are — and may have more to do with their lifestyle. A new study with the NASA/ESA Hubble Space Telescope reveals that the same is true of star clusters.

Globular clusters are spherical collections of stars, tightly bound to each other by their mutual gravity. Relics of the early years of the Universe, with ages of typically 12-13 billion years (the Big Bang took place 13.7 billion years ago), there are roughly 150 globular clusters in the Milky Way and they contain many of our galaxy’s oldest stars.

The globular cluster NGC 6388 observed by the MPG/ESO 2.2-metre

But while the stars are old and the clusters formed in the distant past, astronomers using the NASA/ESA Hubble Space Telescope and the MPG/ESO 2.2-metre telescope at the ESO La Silla Observatory have found that some of these clusters are still young at heart. The research is presented in the 20 December 2012 issue of the journal Nature.

“Although these clusters all formed billions of years ago,” says Francesco Ferraro (University of Bologna), the leader of the team that made the discovery, “we wondered whether some might be aging faster or slower than others. By studying the distribution of a type of blue star that exists in the clusters, we found that some clusters had indeed evolved much faster over their lifetimes, and we developed a way to measure the rate of aging.”

NGC 6388 seen by Hubble and ESO

Star clusters form in a short period of time, meaning that all the stars within them tend to have roughly the same age. Because bright, high-mass stars burn up their fuel quite quickly, and globular clusters are very old, there should only be low-mass stars still shining within them.

This, however, turns out not to be the case: in certain circumstances, stars can be given a new burst of life, receiving extra fuel that bulks them up and substantially brightens them. This can happen if one star pulls matter off a neighbour, or if they collide. The re-invigorated stars are called blue stragglers [1], and their high mass and brightness are properties that lie at the heart of this study.

Globular clusters seen by Hubble and ESO

Image above: This collage shows a range of globular clusters, which were studied using Hubble and the MPG/ESO 2.2-metre telescope. The data show that, despite all forming at roughly the same time, the clusters have aged at dramatically different rates, with heavier stars sinking to the centres of the clusters in a process similar to sedimentation. Collage description:

Top row: M 4 (ESO), Omega Cen (ESO), M 80 (Hubble)
Middle row: M 53 (Hubble), NGC 6752 (Hubble), M 13 (Hubble)
Bottom row: M 4 (Hubble), NGC 288 (Hubble), 47 Tuc (Hubble)

Heavier stars sink towards the centre of a cluster as the cluster ages, in a process similar to sedimentation. Blue stragglers’ high masses mean they are strongly affected by this process, while their brightness makes them relatively easy to observe [2].

To better understand cluster aging, the team mapped the location of blue straggler stars in 21 globular clusters, as seen in images from Hubble and the MPG/ESO 2.2-metre telescope at the ESO La Silla Observatory, among other observatories [3]. Hubble provided high resolution imagery of the crowded centres of 20 of the clusters, while the ground-based imagery gave a wider view of their less busy outer regions.

Analysing the observational data, the team found that a few clusters appeared young, with blue straggler stars distributed throughout, while a larger group appeared old, with the blue stragglers clumped in the centre. A third group was in the process of aging, with the stars closest to the core migrating inwards first, then stars ever further out progressively sinking towards the centre.

Evolution of globular clusters

“Since these clusters all formed at roughly the same time, this reveals big differences in the speed of evolution from cluster to cluster,” said Barbara Lanzoni (University of Bologna, Italy), a co-author of the study. “In the case of fast-aging clusters, we think that the sedimentation process can be complete within a few hundred million years, while for the slowest it would take several times the current age of the Universe.”

As a cluster’s heaviest stars sink towards the centre, the cluster eventually experiences a phenomenon called core collapse, where the centre of the cluster bunches together extremely densely.

The processes leading towards core collapse are quite well understood, and revolve around the number, density and speed of movement of the stars [4]. However, the rate at which they happened was not known until now. This study provides the first empirical way of investigating these different rates of aging.


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

The international team of astronomers in this study consists of F.R. Ferraro (University of Bologna, Italy), B. Lanzoni (University of Bologna, Italy), E. Dalessandro (University of Bologna, Italy), G. Beccari (European Southern Observatory), M. Pasquato (University of Bologna, Italy), P. Miocchi (University of Bologna, Italy), R.T. Rood (University of Virginia, USA), S. Sigurdsson (Pennsylvania State University, USA),, A. Sills (McMaster University, Canada), E. Vesperini (Indiana University, USA), M. Mapelli (INAF/Padua Observatory, Italy), R. Contreras (University of Bologna, Italy), N. Sanna (University of Bologna, Italy), A. Mucciarelli (University of Bologna, Italy)

This research is part of the Cosmic-Lab project ( funded by the ERC (European Research Council) for a total amount of € 1.8 million for 5 years. Set up in 2007 by the European Union, the ERC aims to stimulate scientific excellence in Europe by encouraging competition for funding between the very best, creative researchers of any nationality and age. Since its launch, the ERC has funded over 2 500 researchers and their frontier research projects across Europe. The ERC operates according to an "investigator-driven", or "bottom-up", approach, allowing researchers to identify new opportunities in all fields of research (Physical Sciences and Engineering, Life Sciences, and Social Sciences and Humanities). It has also become a benchmark of the competitiveness of national research systems and complements existing funding schemes at national and European levels. The ERC, which is the newest component of the EU's Seventh Research Framework Programme, has a total budget of €7.5 billion from 2007 to 2013. Last year, the European Commission proposed a substantial increase in the ERC's budget for 2014 to 2020 under the new framework programme ('Horizon 2020'). The ERC is composed of an Executive Agency and a Scientific Council. The Scientific Council is made up of 22 top researchers and sets the ERC's scientific strategy. The ERC is led by President Prof. Helga Nowotny and the Scientific Council is represented in Brussels by Secretary General Prof. Donald Dingwell. The ERC Executive Agency implements the "Ideas" Specific Programme and is led by Director (ad int.) Pablo Amor.

[1] Blue stragglers are so called because of their blue colour, and the fact that their evolution lags behind that of their neighbours.

[2] Blue stragglers combine being relatively bright and high mass by the standards of globular cluster stars, but they are not the only stars within these clusters that are either bright or massive.

Red giant stars are brighter, but they have a much lower mass, and therefore are not affected by the sedimentation process in the same way. (It is easy to distinguish these from blue stragglers because their colour is very different.)

Neutron stars, the extremely dense cores of stars much bigger than the Sun that exploded billions of years ago in the early history of globular clusters, have a similar mass to blue stragglers, and are affected by the sedimentation process, but they are incredibly difficult to observe and therefore do not make a useful subject for this study.

Blue stragglers are the only stars within clusters which combine high mass and high brightness.

[3] Of the 21 clusters covered by this research, 20 were studied with Hubble, 12 with the MPG/ESO 2.2-metre telescope, eight with the Canada-France-Hawaii telescope and one with NAOJ’s Subaru Telescope.

[4] Such a rate depends in a complex manner on the number of stars,  their density and their velocity within a cluster. While the first two quantities are relatively easy to measure, velocity is not. For these reasons, previous estimates of the rate of globular cluster dynamical aging were based only on theoretical arguments, while the new method allows a totally empirical measurement.

    Images of Hubble:

    Cosmic Lab press release:

    ESO press release:

    European Research Council:

    Research paper:

Images, Text, Credit: NASA / ESA / ESO / F. Ferraro and B. Lanzoni (University of Bologna) / Hubble Heritage Team (STScI/AURA) / G. Meylan EPFL (École Polytechnique Federale de Lausanne) / Video: NASA, ESA, L. Calçada, F. Ferraro (University of Bologna).


Monster Black Holes

NASA - Chandra X-ray Observatory patch.

Dec. 19, 2012

The black hole at the center of this galaxy is part of a survey of 18 of the biggest black holes in the universe. This large elliptical galaxy is in the center of the galaxy cluster PKS 0745-19, which is located about 1.3 billion light years from Earth.. X-ray data from NASA's Chandra X-ray Observatory are shown in purple and optical data from the Hubble Space Telescope are in yellow.

The researchers found that these black holes may be about ten times more massive than previously thought, with at least ten of them weighing between 10 and 40 billion times the mass of the sun.

All of the potential "ultramassive" black holes found in this study lie in galaxies at the centers of galaxy clusters containing huge amounts of hot gas. This hot gas produces the diffuse X-ray emission seen in the image. Outbursts powered by the central black holes create cavities in the gas preventing it from cooling and forming enormous numbers of stars. To generate the outbursts, the black holes must swallow large amounts of mass. Because the largest black holes can swallow the most mass and power the biggest outbursts, ultramassive black holes had already been predicted to exist to explain some of the most powerful outbursts seen.

Chandra X-ray Observatory

In addition to the X-rays from Chandra, the new study also uses radio data from the NSF's Karl G. Jansky Very Large Array (JVLA) and the Australia Telescope Compact Array (ATCA) and infrared data from the 2 Micron All-Sky Survey (2MASS). These results were published [link to press release] in the July 2012 issue of The Monthly Notices of the Royal Astronomical Society.

Read more/access all images:

Chandra's Flickr photoset:

The Monthly Notices of the Royal Astronomical Society:

Images, Text, Credits: X-ray: NASA / CXC / Stanford / Hlavacek-Larrondo, J. et al; Optical: NASA / STScI / Northrop Grumman.

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Exp. 34 Crew on Way to International Space Station

ROSCOSMOS - Soyuz TMA-07M Mission patch.

Dec. 19, 2012

 Soyuz TMA-07M ready for launch. Image Credits: NASA TV / Aerospace.

The Soyuz TMA-07M launched from the Baikonur Cosmodrome in Kazakhstan to the International Space Station at 7:12 a.m. EST. NASA astronaut Tom Marshburn, Canadian Space Agency astronaut Chris Hadfield and Russian cosmonaut Roman Romanenko now are safely in orbit.

Image above: Expedition 34 Flight Engineers Tom Marshburn, Roman Romanenko and Chris Hadfield launch aboard the Soyuz TMA-07M spacecraft from the Baikonur Cosmodrome in Kazakhstan. Photo Credit: NASA TV.

Flight Engineers Tom Marshburn, Roman Romanenko and Chris Hadfield will orbit the Earth for two days before docking to the Rassvet module at 9:12 a.m. Friday. The new trio will join Commander Kevin Ford and Flight Engineers Oleg Novitskiy and Evgeny Tarelkin who’ve been residing at the orbital laboratory since Oct. 26.

Expedition 34/35 Launches to the International Space Station

The crew will dock with the station’s Rassvet module at 9:12 a.m. Friday, Dec. 21. Welcoming them aboard will be the current station residents.

Image above: Expedition 34 crew's Tom Marshburn and Roman Romanenko inside Soyuz TMA-07M during the launch. Image Credits: NASA TV / Aerospace.

Hadfield last visited the station in April 2001 aboard space shuttle Endeavour as an STS-100 mission specialist. He helped install the Canadarm2, the station’s robotic arm, during two spacewalks. Hadfield will be Canada’s first station commander when Expedition 35 begins. Marshburn went to the station in July 2009 aboard shuttle Endeavour for the STS-127 mission. He performed three spacewalks to help complete the construction of the Japanese Kibo laboratory module.

Romanenko served as a flight engineer for Expedition 20/21 for six months in 2009.

Image above: Space Station crew watching the launch on NASA TV. Image Credits: NASA TV / Aerospace.

Expedition 34 will be a six-member crew until March 2013 when Ford, Novitskiy and Tarelkin undock from the Poisk module and return home inside the Soyuz TMA-06M spacecraft for a landing in Kazakhstan. When they undock Expedition 35 will officially begin as Hadfield becomes commander staying behind with Marshburn and Romanenko before finally returning home in May 2013.

Back on Earth three more crew members are training for their upcoming launch to the station. NASA astronaut Chris Cassidy and cosmonauts Alexander Misurkin and Pavel Vinogradov will complete the Expedition 35 crew when they launch to the orbiting laboratory in March 2013.

Read more about Expedition 34:

For more information about the International Space Station, visit:

Images, Video, Text, Credits: ROSCOSMOS / NASA / NASA TV / Aerospace.


mardi 18 décembre 2012

Shot Away from its Companion, Giant Star Makes Waves

NASA - SPITZER Space Telescope patch.

Dec. 18, 2012

The giant star Zeta Ophiuchi is having a "shocking" effect on the surrounding dust clouds in this infrared image from NASA’s Spitzer Space Telescope. Image credit: NASA/JPL-Caltech.

Like a ship plowing through still waters, the giant star Zeta Ophiuchi is speeding through space, making waves in the dust ahead. NASA's Spitzer Space Telescope has captured a dramatic, infrared portrait of these glowing waves, also known as a bow shock.

Astronomers theorize that this star was once sitting pretty next to a companion star even heftier than itself. But when that star died in a fiery explosion, Zeta Ophiuchi was kicked away and sent flying. Zeta Ophiuchi, which is 20 times more massive and 80,000 times brighter than our sun, is racing along at about 54,000 mph (24 kilometers per second).

In this view, infrared light that we can't see with our eyes has been assigned visible colors. Zeta Ophiuchi appears as the bright blue star at center. As it charges through the dust, which appears green, fierce stellar winds push the material into waves. Where the waves are the most compressed, and the warmest, they appear red. This bow shock is analogous to the ripples that precede the bow of a ship as it moves through the water, or the pileup of air ahead of a supersonic airplane that results in a sonic boom.

SPITZER Space Telescope. Image credit: NASA/JPL-Caltech

NASA's Wide-field Infrared Survey Explorer, or WISE, released a similar picture of the same object in 2011. WISE sees infrared light as does Spitzer, but WISE was an all-sky survey designed to take snapshots of the entire sky. Spitzer, by contrast, observes less of the sky, but in more detail. The WISE image can be seen at: .

NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. Data are archived at the Infrared Science Archive housed at the Infrared Processing and Analysis Center at Caltech. Caltech manages JPL for NASA. For more information about Spitzer, visit: and

Images (mentioned), Text, Credits: NASA / JPL / Whitney Clavin.

Best regards,