Swiss Air Force - The Gripen saga continues ...

Swiss Air Force patch.

Feb. 14, 2013

 Six Northrop F-5E Tiger II of the Patrouille Suisse

Latest news of the day: The Swiss defense minister wants grounded Patrouille Suisse since 2016!

What are the problems of the Patrouille Suisse:

The reasons cited by the defense minister are once again wrong. The annual cost of this patrol is ridiculous expense comparisons other military spendings, and I want to reiterate that the Patrouille Suisse is very popular in Switzerland and abroad, or they are the "card" of our Air Force and our entire army as the military band (Military Tatoo) who are our only two ambassadors of the Swiss Army.

The Patrouille Suisse viewed inside the cockpit of the leader solo

We never see the Swiss military abroad (apart from the Vatican Guard in Roma and KFOR in Kosovo), because Switzerland is a neutral country and our army only defensive.

The real reasons he has mentioned himself during his interview with Swiss television, the Minister issues are simple:

- Not enough money for its proposed purchase of Gripen, because he knows that the total cost of the Gripen will be much higher than the advertised price in Swiss people and parliamentarians, in fact, any military aviation specialist you say that the proposed purchase of Gripen aircraft (for more information on this project, see my previous article) is worse and more expensive first officially announced (4 billion will be reached), the initial budget more 3.1 Billion has already been revised upwards twice, we get now more than 3.5 billion (all amounts are expressed in Swiss Francs).

- Not enough aircraft, 22 aircraft will be ordered to replace provided aerial surveillance of Switzerland sky and he has already reduced the activity to office hours (07:00-19:00), as customs officials... Personally, I did not know that the Schengen agreements included airspace ... This is new?

Swiss Air Force Northrop F-5E Tiger II

The real problem is just a matter of calculation: there are 42 Northrop F-5E Tiger II still in service, this aircraft is to be replaced by Gripen, if one incorporates the Patrouille Suisse 11 aircraft made by the Gripen, there will be more than 11 aircraft to ensure air monitoring in the country and it is not enough if one takes into account the rotation of service units (flight hours and ground maintenance and revisions).

Founded in 1963, the Patrouille Suisse is like all patrols made famous the "cream" of the countrie pilots.

The Patrouille Suisse

Controversies are recurrent in Switzerland each new aircraft purchases in 1973 when evaluating the Northrop F-5E Tiger II (98 aircafts total purchased) they have been the same kinds of problems that currently, except that in is era, the minister in place had the decency not to use this file for personal, in order to justify one sucked (purchase of Gripen) to ministry mandate forgotten more than lukewarm ... All this at the expense of the country's security and military morale (they have at the bottom of the military boots "Ranger's").

So with the purchase of Gripen aircraft we have the worst performer of his generation, he does not exist (E/F model), it has never been tested, it will be much more expensive than expected, there will not be enough planes to replace those currently in use, so no more Patrouille Suisse ... Where are the positive choice of Gripen?

The film "Tigris Helveticus" produced by the Swiss army in 1981, demonstrates that there has been controversy in these years about buying the Northrop F-5E Tiger II, as today Gripen and Rafale. Note that the fighters Saab 37 Viggen and the Mirage F-1 (Saab / Dassault) was already present in the 4 planes tested had at that time.

Image taken from the movie "Tigris Helveticus" presents the 4 aircrafts had set evaluation in 1974

Furthermore, seen from abroad, we go for the Gripen with horns, this is probably one of the reasons why some countries (apart from the Swedish Air Force, which as all aircraft manufacturers in their own country team) I mean the Gripen model "E/F", because as I've written before, this plane does not yet exist, it is in the development stage. I do not know which countries buy a ghost plane ... If! the Swiss!

Link to my previous article about the purchase of a new fighter aircraft for the Swiss Air Force:
http://orbiterchspacenews.blogspot.ch/2013/01/choice-of-new-fighter-aircraft-of-swiss.html

Images, Text, Credits: Swiss Army / Orbiter.ch Aerospace.

Greetings, Orbiter.ch

Clues to the Mysterious Origin of Cosmic Rays

ESO - European Southern Observatory logo.

14 February 2013

VLT probes remains of medieval supernova

VLT/VIMOS observations of the shock front in the remnant of the supernova SN 1006

Very detailed new observations with ESO’s Very Large Telescope (VLT) of the remains of a thousand-year-old supernova have revealed clues to the origins of cosmic rays. For the first time the observations suggest the presence of fast-moving particles in the supernova remnant that could be the precursors of such cosmic rays. The results are appearing in the 14 February 2013 issue of the journal Science.

In the year 1006 a new star was seen in the southern skies and widely recorded around the world. It was many times brighter than the planet Venus and may even have rivaled the brightness of the Moon. It was so bright at maximum that it cast shadows and it was visible during the day. More recently astronomers have identified the site of this supernova and named it SN 1006. They have also found a glowing and expanding ring of material in the southern constellation of Lupus (The Wolf) that constitutes the remains of the vast explosion.

The remnant of the supernova SN 1006 seen at many different wavelengths

It has long been suspected that such supernova remnants may also be where some cosmic rays — very high energy particles originating outside the Solar System and travelling at close to the speed of light — are formed. But until now the details of how this might happen have been a long-standing mystery.

A team of astronomers led by Sladjana Nikolić (Max Planck Institute for Astronomy, Heidelberg, Germany [1]) has now used the VIMOS instrument on the VLT to look at the one-thousand-year-old SN 1006 remnant in more detail than ever before. They wanted to study what is happening where high-speed material ejected by the supernova is ploughing into the stationary interstellar matter — the shock front. This expanding high-velocity shock front is similar to the sonic boom produced by an aircraft going supersonic and is a natural candidate for a cosmic particle accelerator.

For the first time the team has not just obtained information about the shock material at one point, but also built up a map of the properties of the gas, and how these properties change across the shock front. This has provided vital clues to the mystery.

Part of the supernova remnant SN 1006 seen with the NASA/ESA Hubble Space Telescope

The results were a surprise — they suggest that there were many very rapidly moving protons in the gas in the shock region [2]. While these are not the sought-for high-energy cosmic rays themselves, they could be the necessary “seed particles”, which then go on to interact with the shock front material to reach the extremely high energies required and fly off into space as cosmic rays.

Nikolić explains: “This is the first time we were able to take a detailed look at what is happening in and around a supernova shock front. We found evidence that there is a region that is being heated in just the way one would expect if there were protons carrying away energy from directly behind the shock front.”

The study was the first to use an integral field spectrograph [3] to probe the properties of the shock fronts of supernova remnants in such detail. The team now is keen to apply this method to other remnants.

Co-author Glenn van de Ven of the Max Planck Institute for Astronomy, concludes: “This kind of novel observational approach could well be the key to solving the puzzle of how cosmic rays are produced in supernova remnants.”

Notes:

[1] The new evidence emerged during analysis of the data by Sladjana Nikolić (Max Planck Institute for Astronomy) as part of work towards her doctoral degree at the University of Heidelberg.

[2] These protons are called suprathermal as they are moving much quicker than expected simply from the temperature of the material.

[3] This is achieved using a feature of VIMOS called an integral field unit, where the light recorded in each pixel is separately spread out into its component colours and each of these spectra recorded. The spectra can then be subsequently analysed individually and maps of the velocities and chemical properties of each part of the object created.

More information:

This research was presented in a paper “An Integral View of Fast Shocks around Supernova 1006” to appear in the journal Science on 14 February 2013.

The team is composed of Sladjana Nikolić (Max Planck Institute for Astronomy [MPIA], Heidelberg, Germany), Glenn van de Ven (MPIA), Kevin Heng (University of Bern, Switzerland), Daniel Kupko (Leibniz Institute for Astrophysics Potsdam [AIP], Potsdam, Germany), Bernd Husemann (AIP), John C. Raymond (Harvard-Smithsonian Center for Astrophysics, Cambridge, USA), John P. Hughes (Rutgers University, Piscataway, USA), Jesús Falcon-Barroso (Instituto de Astrofísica de Canarias, La Laguna, Spain).

ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 15 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning the 39-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

Link:

Photos of the VLT: http://www.eso.org/public/images/archive/category/paranal/

Images, Text, Credits: ESO, Radio: NRAO/AUI/NSF/GBT/VLA/Dyer, Maddalena & Cornwell, X-ray: Chandra X-ray Observatory; NASA/CXC/Rutgers/G. Cassam-Chenaï, J. Hughes et al., Visible light: 0.9-metre Curtis Schmidt optical telescope; NOAO/AURA/NSF/CTIO/Middlebury College/F. Winkler and Digitized Sky Survey /  ESA, and the Hubble Heritage Team (STScI/AURA). Acknowledgment: W. Blair (Johns Hopkins University).

Best regards, Orbiter.ch

NASA's Fermi Proves Supernova Remnants Produce Cosmic Rays

NASA - Fermi Gamma-ray Space Telescope logo.

Feb. 14, 2013

A new study using observations from NASA's Fermi Gamma-ray Space Telescope reveals the first clear-cut evidence the expanding debris of exploded stars produces some of the fastest-moving matter in the universe. This discovery is a major step toward understanding the origin of cosmic rays, one of Fermi's primary mission goals.

Fermi Proves Supernova Remnants Produce Cosmic Rays

Video above: The husks of exploded stars give rise to some of the fastest particles in the cosmos. New findings by NASA's Fermi show that two supernova remnants accelerate protons to near the speed of light. These protons interact with nearby interstellar gas clouds, which then emit gamma rays. Credit: NASA's Goddard Space Flight Center.

"Scientists have been trying to find the sources of high-energy cosmic rays since their discovery a century ago," said Elizabeth Hays, a member of the research team and Fermi deputy project scientist at NASA's Goddard Space Flight Center in Greenbelt, Md. "Now we have conclusive proof supernova remnants, long the prime suspects, really do accelerate cosmic rays to incredible speeds."

Cosmic rays are subatomic particles that move through space at almost the speed of light. About 90 percent of them are protons, with the remainder consisting of electrons and atomic nuclei. In their journey across the galaxy, the electrically charged particles are deflected by magnetic fields. This scrambles their paths and makes it impossible to trace their origins directly.

Through a variety of mechanisms, these speedy particles can lead to the emission of gamma rays, the most powerful form of light and a signal that travels to us directly from its sources.

Image above: The W44 supernova remnant is nestled within and interacting with the molecular cloud that formed its parent star. Fermi's LAT detects GeV gamma rays (magenta) produced when the gas is bombarded by cosmic rays, primarily protons. Radio observations (yellow) from the Karl G. Jansky Very Large Array near Socorro, N.M., and infrared (red) data from NASA's Spitzer Space Telescope reveal filamentary structures in the remnant's shell. Blue shows X-ray emission mapped by the Germany-led ROSAT mission. Credit: NASA/DOE/Fermi LAT Collaboration, NRAO/AUI, JPL-Caltech, ROSAT.

Since its launch in 2008, Fermi's Large Area Telescope (LAT) has mapped million- to billion-electron-volt (MeV to GeV) gamma-rays from supernova remnants. For comparison, the energy of visible light is between 2 and 3 electron volts.

The Fermi results concern two particular supernova remnants, known as IC 443 and W44, which scientists studied to prove supernova remnants produce cosmic rays. IC 443 and W44 are expanding into cold, dense clouds of interstellar gas. These clouds emit gamma rays when struck by high-speed particles escaping the remnants.

Scientists previously could not determine which atomic particles are responsible for emissions from the interstellar gas clouds because cosmic ray protons and electrons give rise to gamma rays with similar energies. After analyzing four years of data, Fermi scientists see a distinguishable feature in the gamma-ray emission of both remnants. The feature is caused by a short-lived particle called a neutral pion, which is produced when cosmic ray protons smash into normal protons. The pion quickly decays into a pair of gamma rays, emission that exhibits a swift and characteristic decline at lower energies. The low-end cutoff acts as a fingerprint, providing clear proof that the culprits in IC 443 and W44 are protons.

The findings will appear in Friday's issue of the journal Science.

"The discovery is the smoking gun that these two supernova remnants are producing accelerated protons," said lead researcher Stefan Funk, an astrophysicist with the Kavli Institute for Particle Astrophysics and Cosmology at Stanford University in Calif. "Now we can work to better understand how they manage this feat and determine if the process is common to all remnants where we see gamma-ray emission."

This multiwavelength composite shows the supernova remnant IC 443, also known as the Jellyfish Nebula. Fermi GeV gamma-ray emission is shown in magenta, optical wavelengths as yellow, and infrared data from NASA's Wide-field Infrared Survey Explorer (WISE) mission is shown as blue (3.4 microns), cyan (4.6 microns), green (12 microns) and red (22 microns). Cyan loops indicate where the remnant is interacting with a dense cloud of interstellar gas. Credit: NASA/DOE/Fermi LAT Collaboration, NOAO/AURA/NSF, JPL-Caltech/UCLA.

In 1949, the Fermi telescope's namesake, physicist Enrico Fermi, suggested the highest-energy cosmic rays were accelerated in the magnetic fields of interstellar gas clouds. In the decades that followed, astronomers showed supernova remnants were the galaxy's best candidate sites for this process.

A charged particle trapped in a supernova remnant's magnetic field moves randomly throughout the field and occasionally crosses through the explosion's leading shock wave. Each round trip through the shock ramps up the particle's speed by about 1 percent. After many crossings, the particle obtains enough energy to break free and escape into the galaxy as a newborn cosmic ray.

The supernova remnant IC 443, popularly known as the Jellyfish Nebula, is located 5,000 light-years away toward the constellation Gemini and is thought to be about 10,000 years old. W44 lies about 9,500 light-years away toward the constellation Aquila and is estimated to be 20,000 years old. Each is the expanding shock wave and debris formed when a massive star exploded.

The Fermi discovery builds on a strong hint of neutral pion decay in W44 observed by the Italian Space Agency's AGILE gamma ray observatory and published in late 2011.

AGILE gamma ray observatory (left) - Fermi Gamma-ray Space Telescope (right). Image Credits: NASA / JPL-Caltech / ASI.

NASA's Fermi Gamma-ray Space Telescope is an astrophysics and particle physics partnership. Goddard manages Fermi. The telescope was developed in collaboration with the U.S. Department of Energy, with contributions from academic institutions and partners in the United States France, Germany, Italy, Japan, and Sweden.

Related Links:

Download video in HD formats from NASA Goddard's Scientific Visualization Studio and print resolution images: http://svs.gsfc.nasa.gov/vis/a010000/a011200/a011209/

SLAC press release: http://www6.slac.stanford.edu/news/2013-02-14-fermi-cosmic-rays.aspx

"NASA's Fermi Shows That Tycho's Star Shines in Gamma Rays" (12.13.11):
http://www.nasa.gov/mission_pages/GLAST/news/tycho-star.html

"NASA's Fermi Closes on Source of Cosmic Rays" (02.16.10): http://www.nasa.gov/mission_pages/GLAST/news/cosmic-rays-source.html#

Supernova Remnants and Cosmic Ray Acceleration at NASA's Imagine the Universe!: http://imagine.gsfc.nasa.gov/docs/features/topics/snr_group/cosmic_rays.html

Fermi Gamma-ray Space Telescope: http://www.nasa.gov/fermi

Images (mentioned), Video (mentioned), Text, Credit: NASA's Goddard Space Flight Center / Francis Reddy.

Cheers, Orbiter.ch

At the Mouth of the Red Valley

ESA - Mars Express Mission patch.

14 February 2013

ESA’s Mars Express took a high-resolution stereo image on 13 January of the southeast corner of the Amenthes Planum region on Mars, near to Palos crater and the mouth of a well-known sinuous valley, Tinto Vallis.

Southeast of Amenthes Planum

At the bottom-centre of the full-colour image above, and up close in the first perspective image, is a nearby shorter and wider valley, which is fed by a number of tributaries before it joins the mouth of Tinto Vallis as both empty into Palos crater, just off the bottom of the image.

The 190 km-long Tinto Vallis is seen in the context image and is named after the famous Rio Tinto river in the Andalucía region of Spain. It is believed to have formed around 3.7 billion years ago, during the early history of Mars.

Valley feeding Palos Crater

The network of shorter valleys shown in the first perspective image is thought to have formed through volcanic activity melting subsurface ice and liberating water to the martian surface via seeps and springs.

If underground water emerges to the surface from the side of a slope – a process that planetary geologists call ‘groundwater sapping’ – it weakens the ground above it, causing it to collapse. Over time, this process may lead to the formation of steep-sided U-shaped valleys.

Amenthes Planum in context

Groundwater sapping is believed to be responsible for erosion seen in many of the valley networks on the Red Planet.

Another eye-catching feature is the relatively deep 35 km-wide crater seen in the left-hand portion of the colour, topographic and 3D images. Spectacular landslides along the crater’s walls can be seen and are particularly evident along the broken southern (left) rim.

Amenthes Planum topography

This crater sits on top of at least three older craters, the largest of which is 100 km wide and dominates the whole top left half of the 2D and 3D anaglyph images. The western rim of this crater continues beyond the image frame, and can be more easily distinguished in the context image.

The floor of this 100 km-wide crater is chaotic, with flat-topped geological features called mesas, and their smaller siblings, buttes, littering the floor. These are probably the result of the removal of subsurface water ice leading to the collapse of weaker material around them, leaving these more resistant high-sided features behind.

On Earth, the desert regions in Utah are home to many examples of these types of formation.

Trough feeding Amenthes Planum

Toward the north (right) side of the 2D images, several smaller craters display very smooth and flat floors, from infilling by sediments.

The darker regions to the far north and south shown most clearly in the first colour image are covered in wind-transported basaltic sands.

The smooth low-lying region to the far right and shown in the second perspective image is a small trough that feeds into the broader lava field of Amenthes Planum. The trough has likely been modified by the outflow of material from the ancient lake that may have once existed in Palos crater, the rim of which can only just be seen at the bottom of the colour, topographic and 3D images.

Amenthes Planum in 3D

This smooth, channel-like feature brushes against the rim of a 30 km-wide crater, and both have been covered with dark wind-blown materials.

With these recent images, Mars Express continues to show the similarities between regions on Mars with those on our home planet.

Related links:

Mars Express overview: http://www.esa.int/Our_Activities/Space_Science/Mars_Express_overview

Mars Express in depth: http://sci.esa.int/science-e/www/area/index.cfm?fareaid=9

High Resolution Stereo Camera: http://berlinadmin.dlr.de/Missions/express/indexeng.shtml

Behind the lens: http://www.esa.int/Our_Activities/Space_Science/Mars_Express/Behind_the_lens

Frequently asked questions: http://www.esa.int/Our_Activities/Space_Science/Mars_Express/Frequently_asked_questions

ESA Planetary Science archive (PSA): http://www.rssd.esa.int/PSA

NASA Planetary Data System: http://pds-geosciences.wustl.edu/missions/mars_express/hrsc.htm

HRSC data viewer: http://hrscview.fu-berlin.de/

Mars Webcam: http://blogs.esa.int/vmc

Images, Text, Credits: ESA / DLR / FU Berlin (G. Neukum).

Best regards, Orbiter.ch

"A drop of ink on the luminous sky"

ESO - European Southern Observatory logo.

13 February 2013

Wide Field Imager snaps cosmic gecko

The bright star cluster NGC 6520 and the strangely shaped dark cloud Barnard 86

This image from the Wide Field Imager on the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile, shows the bright star cluster NGC 6520 and its neighbour, the strange gecko-shaped dark cloud Barnard 86. This cosmic pair is set against millions of glowing stars from the brightest part of the Milky Way — a region so dense with stars that barely any dark sky is seen across the picture.

This part of the constellation of Sagittarius (The Archer) is one of the richest star fields in the whole sky — the Large Sagittarius Star Cloud. The huge number of stars that light up this region dramatically emphasise the blackness of dark clouds like Barnard 86, which appears at the centre of this new picture from the Wide Field Imager, an instrument mounted on the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile.

The cluster NGC 6520 and the dark cloud Barnard 86 in the constellation of Sagittarius

This object, a small, isolated dark nebula known as a Bok globule [1], was described as “a drop of ink on the luminous sky” by its discoverer Edward Emerson Barnard [2], an American astronomer who discovered and photographed numerous comets, dark nebulae, one of Jupiter’s moons, and made many other contributions. An exceptional visual observer and keen astrophotographer, Barnard was the first to use long-exposure photography to explore dark nebulae.

Through a small telescope Barnard 86 looks like a dearth of stars, or a window onto a patch of distant, clearer sky. However, this object is actually in the foreground of the star field — a cold, dark, dense cloud made up of small dust grains that block starlight and make the region appear opaque. It is thought to have formed from the remnants of a molecular cloud that collapsed to form the nearby star cluster NGC 6520, seen just to the left of Barnard 86 in this image.

Wide-field view of the star cluster NGC 6520 and the dark cloud Barnard 86

NGC 6520 is an open star cluster that contains many hot stars that glow bright blue-white, a telltale sign of their youth. Open clusters usually contain a few thousand stars that all formed at the same time, giving them all the same age. Such clusters usually only live comparatively short lives, on the order of several hundred million years, before drifting apart.

Zooming into the star cluster NGC 6520 and the dark cloud Barnard 86

The incredible number of stars in this area of the sky muddles observations of this cluster, making it difficult to learn much about it. NGC 6520’s age is thought to be around 150 million years, and both this star cluster and its dusty neighbour are thought to lie at a distance of around 6000 light-years from our Sun.

Panning across the star cluster NGC 6520 and the dark cloud Barnard 86

The stars that appear to be within Barnard 86 in the image above are in fact in front of it, lying between us and the dark cloud. Although it is not certain whether this is still happening within Barnard 86, many dark nebulae are known to have new stars forming in their centres  — as seen in the famous Horsehead Nebula (eso0202), the striking object Lupus 3 (eso1303) and to a lesser extent in another of Barnard’s discoveries, the Pipe Nebula (eso1233). However, the light from the youngest stars is blocked by the surrounding dusty regions, and they can only be seen in infrared or longer-wavelength light.

Video above: Infrared/visible-light crossfade view of the star cluster NGC 6520 and the dark cloud Barnard 86

Notes:

[1] Bok globules were first observed in the 1940s by astronomer Bart Bok. They are very cold, dark clouds of gas and dust that often have new stars forming at their centres. These globules are rich in dust that scatters and absorbs background light, so they are almost opaque to visible light.

[2] This quotation comes from E. E. Barnard, Dark Regions in the Sky Suggesting an Obscuration of Light, Yerkes Observatory, Nov 15 1913 (available online here).

More information:

ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive astronomical observatory. It is supported by 15 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning the 39-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

Links:

Information about the MPG/ESO 2.2-metre telescope: http://www.eso.org/sci/facilities/lasilla/telescopes/2p2/

Information about the La Silla Observatory: http://www.eso.org/public/teles-instr/lasilla.html

Images of La Silla: http://www.eso.org/public/images/archive/category/lasilla/

Images, Text, Credits: ESO / Digitized Sky Survey 2. Acknowledgement: Davide De Martin / Videos: ESO / Digitized Sky Survey 2 / Nick Risinger (skysurvey.org) / VVV Survey / Music: movetwo.

Cheers, Orbiter.ch

Supernova Remnant W49B

NASA - Chandra X-ray Observatory patch.

Feb. 13, 2013

The highly distorted supernova remnant shown in this image may contain the most recent black hole formed in the Milky Way galaxy. The image combines X-rays from NASA's Chandra X-ray Observatory in blue and green, radio data from the NSF's Very Large Array in pink, and infrared data from Caltech's Palomar Observatory in yellow.

The remnant, called W49B, is about a thousand years old, as seen from Earth, and is at a distance about 26,000 light years away.

The supernova explosions that destroy massive stars are generally symmetrical, with the stellar material blasting away more or less evenly in all directions. However, in the W49B supernova, material near the poles of the doomed rotating star was ejected at a much higher speed than material emanating from its equator. Jets shooting away from the star's poles mainly shaped the supernova explosion and its aftermath.

By tracing the distribution and amounts of different elements in the stellar debris field, researchers were able to compare the Chandra data to theoretical models of how a star explodes. For example, they found iron in only half of the remnant while other elements such as sulfur and silicon were spread throughout [include the Fe/Si image]. This matches predictions for an asymmetric explosion. Also, W49B is much more barrel-shaped than most other remnants in X-rays and several other wavelengths, pointing to an unusual demise for this star.

Chandra X-ray Observatory

The authors also examined what sort of compact object the supernova explosion left behind. Most of the time, massive stars that collapse into supernovas leave a dense spinning core called a neutron star. Astronomers can often detect these neutron stars through their X-ray or radio pulses, although sometimes an X-ray source is seen without pulsations. A careful search of the Chandra data revealed no evidence for a neutron star, implying an even more exotic object might have formed in the explosion, that is, a black hole.

This may be the youngest black hole formed in the Milky Way galaxy, with an age of only about a thousand years, as viewed from Earth (i.e., not including the light travel time). A well-known example of a supernova remnant in our Galaxy that likely contains a black hole is SS433. This remnant is thought to have an age between 17,000 and 21,000 years, as seen from Earth, making it much older than W49B.

The new results on W49B, which were based on about two-and-a-half days of Chandra observing time, appear in a paper in the Feb. 10, 2013 issue of the Astrophysical Journal. The authors of the paper are Laura Lopez, from the Massachusetts Institute of Technology (MIT), Enrico Ramirez-Ruiz from the University of California at Santa Cruz, Daniel Castro, also of MIT, and Sarah Pearson from the University of Copenhagen in Denmark.

Read more/access all images: http://chandra.harvard.edu/photo/2013/w49b/

Chandra's Flickr photoset: http://www.flickr.com/photos/nasamarshall/sets/72157606205297786/

Images, Text, Credits: Credits: X-ray: NASA / CXC / MIT / L.Lopez et al; Infrared: Palomar; Radio: NSF / NRAO / VLA.

Greetings, Orbiter.ch

Cryosat reveals major loss of Artic sea ice

ESA - Cryosat 2 Mission logo.

13 February 2013

An international team of scientists using new measurements from ESA’s ice mission has discovered that the volume of Arctic sea ice has declined by 36% during autumn and 9% during winter between 2003 and 2012.

Monthly sea ice volume

Satellite records show a constant downward trend in the area covered by Arctic sea ice during all seasons, but in particular in summer. The past six years have seen the lowest summer ice extent in three decades, reaching the lowest last September at about 3.61 million sq km.

A team of scientists led by University College London has now generated estimates of the sea-ice volume for the 2010–11 and 2011–12 winters over the Arctic basin using data from ESA’s CryoSat satellite.

This study has confirmed, for the first time, that the decline in sea ice coverage in the polar region has been accompanied by a substantial decline in ice volume.

The new CryoSat dataset shows the volume’s continuing decline observed from 2003 to 2008 by NASA’s ICESat satellite.

Sea ice thickness

Since 2008, the Arctic has lost about 4300 cubic km of ice during the autumn period and about 1500 cubic km in winter.

The team confirmed CryoSat estimates using independent ground and airborne measurements carried out by ESA and international scientists during the last two years in the polar region, as well as by comparing measurements from NASA’s Operation IceBridge.

“The data reveal that thick sea ice has disappeared from a region to the north of Greenland, the Canadian Archipelago and to the northeast of Svalbard,”  said Katharine Giles, co-author of the study ‘CryoSat-2 estimates of Arctic sea ice thickness and volume’, recently published online in Geophysical Research Letters.

Cryosat 2 satellite

“Other satellites have already shown drops in the area covered by Arctic sea ice as the climate has warmed, but CryoSat allows scientists to estimate the volume of sea ice – a much more accurate indicator of the changes taking place in the Arctic,” added Tommaso Parrinello, CryoSat Mission Manager.

To do this, CryoSat’s high-resolution radar altimeter sends pulses of microwave energy down towards the ice.

The energy bounces off both the top sections of ice and the water in the cracks between. The difference in height between these two surfaces allows scientists to calculate the ‘freeboard’ – the height of ice above the water – and, as a result, volume of the ice cover.

While the researchers say two years of CryoSat data aren’t indicative of a long-term change, they speculate that the lower ice thickness and volume in the winter of 2012, compared to the winter of 2011, may have contributed to the record minimum ice extent during the 2012 autumn.

Related links:

Article: CryoSat-2 estimates of Arctic sea ice thickness and volume: http://onlinelibrary.wiley.com/doi/10.1002/grl.50193/pdf

Geophysical Research Letters: http://www.agu.org/journals/gl/

UK Natural Environment Research Council (NERC): http://www.nerc.ac.uk/

Centre for Polar Observation and Modelling (CPOM): http://www.cpom.org/

University College London: http://www.ucl.ac.uk/

CryoSat: http://www.esa.int/Our_Activities/Observing_the_Earth/CryoSat

NASA’s IceSat satellite: http://www.nasa.gov/mission_pages/icesat/index.html

NASA’s Operation IceBridge: http://www.nasa.gov/mission_pages/icebridge/index.html

PIOMAS: http://psc.apl.washington.edu/wordpress/research/projects/arctic-sea-ice-volume-anomaly/

Images, Video, Text, Credits: ESA / CPOM / UCL / ESA / UW-APL / NSIDC / Planetary Visions / K. Giles et al.

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