mercredi 18 janvier 2017

Chandra Images Show That Geometry Solves a Pulsar Puzzle

NASA - Chandra X-ray Observatory patch.

Jan. 18, 2017

NASA's Chandra X-ray Observatory has taken deep exposures of two nearby energetic pulsars flying through the Milky Way galaxy. The shape of their X-ray emission suggests there is a geometrical explanation for puzzling differences in behavior shown by some pulsars.

Pulsars − rapidly rotating, highly magnetized, neutron stars born in supernova explosions triggered by the collapse of massive stars − were discovered 50 years ago via their pulsed, highly regular, radio emission.  Pulsars produce a lighthouse-like beam of radiation that astronomers detect as pulses as the pulsar's rotation sweeps the beam across the sky.

Since their discovery, thousands of pulsars have been discovered, many of which produce beams of radio waves and gamma rays. Some pulsars show only radio pulses and others show only gamma-ray pulses. Chandra observations have revealed steadier X-ray emission from extensive clouds of high-energy particles, called pulsar wind nebulas, associated with both types of pulsars. New Chandra data on pulsar wind nebulas may explain the presence or absence of radio and gamma-ray pulses.

Image credits: Geminga image: NASA/CXC/PSU/B. Posselt et al; Infrared: NASA/JPL-Caltech; B0355+54: X-ray: NASA/CXC/GWU/N. Klingler et al; Infrared: NASA/JPL-Caltech; Illustrations: Nahks TrEhnl.

This four-panel graphic shows the two pulsars observed by Chandra. Geminga is in the upper left and B0355+54 is in the upper right. In both of these images, Chandra’s X-rays, colored blue and purple, are combined with infrared data from NASA’s Spitzer Space Telescope that shows stars in the field of view. Below each data image, an artist’s illustration depicts more details of what astronomers think the structure of each pulsar wind nebula looks like.

For Geminga, a deep Chandra observation totaling nearly eight days over several years was analyzed to show sweeping, arced trails spanning half a light year and a narrow structure directly behind the pulsar. A five-day Chandra observation of the second pulsar, B0355+54, showed a cap of emission followed by a narrow double trail extending almost five light years.

The underlying pulsars are quite similar, both rotating about five times per second and both aged about half a million years. However, Geminga shows gamma-ray pulses with no bright radio emission, while B0355+54 is one of the brightest radio pulsars known yet not seen in gamma rays.

A likely interpretation of the Chandra images is that the long narrow trails to the side of Geminga and the double tail of B0355+54 represent narrow jets emanating from the pulsar’s spin poles. Both pulsars also contain a torus of emission spreading from the pulsar’s spin equator. These disk-shaped structures and the jets are crushed and swept back as the pulsars fly through the Galaxy at supersonic speeds

In the case of Geminga, the view of the torus is close to edge-on, while the jets point out to the sides.  B0355+54 has a similar structure, but with the torus viewed nearly face-on and the jets pointing nearly directly towards and away from Earth. In B0355+54, the swept-back jets appear to lie almost on top of each other, giving a doubled tail.

Both pulsars have magnetic poles quite close to their spin poles, as is the case for the Earth’s magnetic field. These magnetic poles are the site of pulsar radio emission so astronomers expect the radio beams to point in a similar direction as the jets. By contrast the gamma-ray emission is mainly produced along the spin equator and so aligns with the torus.

For Geminga, astronomers view the bright gamma-ray pulses along the edge of the torus, but the radio beams near the jets point off to the sides and remain unseen. For B0355+54, a jet points almost along our line of sight towards the pulsar. This means astronomers see the bright radio pulses, while the torus and its associated gamma-ray emission are directed in a perpendicular direction to our line of sight, missing the Earth.

Chandra X-ray Observatory. Image Credits: NASA/CXC

These two deep Chandra images have, therefore, exposed the spin orientation of these pulsars, helping to explain the presence, and absence, of the radio and gamma-ray pulses.

The Chandra observations of Geminga and B0355+54 are part of a large campaign, led by Roger Romani of Stanford University, to study six pulsars that have been seen to emit gamma-rays. The survey sample covers a range of ages, spin-down properties and expected inclinations, making it a powerful test of pulsar emission models.

A paper on Geminga led by Bettina Posselt of Penn State University was accepted for publication in The Astrophysical Journal and is available online. A paper on B0355+54 led by Noel Klingler of the George Washington University was published in the December 20th, 2016 issue of The Astrophysical Journal and is available online. NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program for NASA’s Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, controls Chandra’s science and flight operations.

The Astrophysical Journal:

Read More from NASA's Chandra X-ray Observatory:

For more Chandra images, multimedia and related materials, visit:

Images & Illustations (mentioned), Text, Credits: NASA/Lee Mohon.


Galileo: Swiss components have broken down

ESA - GALILEO Programme logo.

Jan. 18, 2017

New glitch for the "European GPS": several of the atomic clocks on board its satellites no longer work.

"This does not affect for the moment" the navigation system that has just started its services, according to the European Space Agency (ESA). "This is a sensitive issue", as atomic clocks are "very important" elements for the smooth operation of the satellite navigation system, which is a competitor to the US GPS, ESA Director General Jan Woerner said, A press conference in Paris.

Galileo satellites

However, in his view, we can not speak of "a new setback" for Galileo, which has experienced many delays and problems since the launch of the program in 1999. Its total cost is about ten billion euros .

So far 18 satellites have been launched. The constellation must count 30 operational satellites and two reserve ones by 2020. "The system is not questioned, not at all", Galileo "continues" but "we want to be transparent," said the official.

Four on each satellite

The atomic clocks of Galileo are supposed to ensure to the European system a very high precision. That is why each satellite carefully carries with it four atomic clocks of two types ("passive hydrogen masers" and rubidium atomic clocks). In order for each satellite to work well on this plane, at least one of the four clocks must be in good working order.

Passive hydrogen masers (atomic clock) by Argotec

Currently 9 out of 72 clocks are down (6 passive hydrogen masers, 3 rubidium atomic clocks), said Woerner, pointing out that "on every satellite there are at least two clocks that work."

"To date, thanks to this redundancy of clocks, none of the satellites in the constellation is out of order," he said.

Swiss Clocks

ESA is investigating the causes of the problem and has successfully restarted one of these clocks when previously it thought to have ten broken down. The satellites concerned have been launched at various times and the last ones, in orbit since November, are also concerned.

"We must learn the behavior of these atomic clocks and how to use them," Woerner said. They are manufactured by SpectraTime, based in Neuchâtel, with partners. SpectraTime confirmed to the ats that its experts are involved in research to identify the causes of the outage.

Rubidium atomic clock by SpectraTime

In this context, should the launch of four new Galileo satellites be delayed by an Ariane 5 rocket planned for the second half of 2017? "It's a sensitive issue," said Woerner. "If we wait and have other failures, we risk reducing the capacity of the system. But if we launch new satellites, they risk taking atomic clocks with problems. "

Do not delay the program

"Personally, I am in favor of not delaying the deployment of the constellation," he added. On 15 December, Europe launched the first services of its Galileo system, with the promise of a more precise location, reserved at present for the few possessors of compatible equipment.

Only a handful of privileged, possessors of the few smartphones compatible with Galileo (the first, the Aquaris X5 Plus of the Spanish manufacturer BQ, has been on the market since the autumn) can for now pick up the new signal.

These pioneers will be able to use the European system free of charge to find a pharmacy, the best route to go on holiday or settle their stride in the marathon. But for a mass arrival of products compatible with Galileo, we will have to be a little patient.

To the nearest centimeter

The European service aims to be more efficient with, in particular, a positioning of a precision, of the order of one meter, greater than that of its competitors. In addition, a paid service will allow a location within a few centimeters.

Galileo constellation

Moreover, the European signal will be dated to a few billionths of a second, a useful service for banks, insurance companies and energy suppliers.

Passive hydrogen masers must precisely ensure a stability of the nanosecond (one billionth of a second) per 24 hours, which is equivalent to losing or gaining a second every 2.7 million years. Rubidium clocks offer an accuracy of 10 nanoseconds per day.

As Galileo is compatible with GPS, the user can access both systems simultaneously and improve the quality and reliability of his position.

What is Galileo?:

ESA GALILEO / Navigation:



Images, Text, Credits: ATS/ESA/Argotec/SpectraTime/ Aerospace/Roland Berga.

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NASA, NOAA Data Show 2016 Warmest Year on Record Globally

NASA Goddard Institute for Space Studies logo.

Jan. 18, 2017

Global temperatures 2012-2016

Earth’s 2016 surface temperatures were the warmest since modern recordkeeping began in 1880, according to independent analyses by NASA and the National Oceanic and Atmospheric Administration (NOAA).

Globally-averaged temperatures in 2016 were 1.78 degrees Fahrenheit (0.99 degrees Celsius) warmer than the mid-20th century mean. This makes 2016 the third year in a row to set a new record for global average surface temperatures.

The 2016 temperatures continue a long-term warming trend, according to analyses by scientists at NASA’s Goddard Institute for Space Studies (GISS) in New York. NOAA scientists concur with the finding that 2016 was the warmest year on record based on separate, independent analyses of the data.

Animated graphic above: The planet’s long-term warming trend is seen in this chart of every year’s annual temperature cycle from 1880 to the present, compared to the average temperature from 1880 to 2015. Record warm years are listed in the column on the right.
Graphic Credits: NASA/Joshua Stevens, Earth Observatory.

Because weather station locations and measurement practices change over time, there are uncertainties in the interpretation of specific year-to-year global mean temperature differences. However, even taking this into account, NASA estimates 2016 was the warmest year with greater than 95 percent certainty.

“2016 is remarkably the third record year in a row in this series,” said GISS Director Gavin Schmidt. “We don’t expect record years every year, but the ongoing long-term warming trend is clear.”

The planet’s average surface temperature has risen about 2.0 degrees Fahrenheit (1.1 degrees Celsius) since the late 19th century, a change driven largely by increased carbon dioxide and other human-made emissions into the atmosphere.

Most of the warming occurred in the past 35 years, with 16 of the 17 warmest years on record occurring since 2001. Not only was 2016 the warmest year on record, but eight of the 12 months that make up the year – from January through September, with the exception of June – were the warmest on record for those respective months. October, November, and December of 2016 were the second warmest of those months on record – in all three cases, behind records set in 2015.

Phenomena such as El Niño or La Niña, which warm or cool the upper tropical Pacific Ocean and cause corresponding variations in global wind and weather patterns, contribute to short-term variations in global average temperature. A warming El Niño event was in effect for most of 2015 and the first third of 2016. Researchers estimate the direct impact of the natural El Niño warming in the tropical Pacific increased the annual global temperature anomaly for 2016 by 0.2 degrees Fahrenheit (0.12 degrees Celsius). 

NASA's Analysis of 2016 Global Temperature

Video above: Animation of global temperatures since 1880. Video Credits: NASA/Scientific Visualization Studio.

Weather dynamics often affect regional temperatures, so not every region on Earth experienced record average temperatures last year. For example, both NASA and NOAA found the 2016 annual mean temperature for the contiguous 48 United States was the second warmest on record. In contrast, the Arctic experienced its warmest year ever, consistent with record low sea ice found in that region for most of the year.

NASA’s analyses incorporate surface temperature measurements from 6,300 weather stations, ship- and buoy-based observations of sea surface temperatures, and temperature measurements from Antarctic research stations. These raw measurements are analyzed using an algorithm that considers the varied spacing of temperature stations around the globe and urban heating effects that could skew the conclusions. The result of these calculations is an estimate of the global average temperature difference from a baseline period of 1951 to 1980.

NOAA scientists used much of the same raw temperature data, but with a different baseline period, and different methods to analyze Earth’s polar regions and global temperatures.

GISS is a laboratory within the Earth Sciences Division of NASA’s Goddard Space Flight Center in Greenbelt, Maryland. The laboratory is affiliated with Columbia University’s Earth Institute and School of Engineering and Applied Science in New York.

NASA monitors Earth's vital signs from land, air and space with a fleet of satellites, as well as airborne and ground-based observation campaigns. The agency develops new ways to observe and study Earth's interconnected natural systems with long-term data records and computer analysis tools to better see how our planet is changing. NASA shares this unique knowledge with the global community and works with institutions in the United States and around the world that contribute to understanding and protecting our home planet.

The full 2016 surface temperature data set and the complete methodology used to make the temperature calculation are available at:

The slides for the Jan. 18, news conference are available at:

For more information about NASA's Earth science programs, visit:

Image, Graphic (mentioned), Video (mentioned), Text, Credits: NASA/Sean Potter/Karen Northon/Goddard Institute for Space Studies/Michael Cabbage/Leslie McCarthy.


mardi 17 janvier 2017

Mars Rover Curiosity Examines Possible Mud Cracks

NASA - Mars Science Laboratory (MSL) patch.

Jan. 17, 2017

Scientists used NASA's Curiosity Mars rover in recent weeks to examine slabs of rock cross-hatched with shallow ridges that likely originated as cracks in drying mud.

"Mud cracks are the most likely scenario here," said Curiosity science team member Nathan Stein. He is a graduate student at Caltech in Pasadena, California, who led the investigation of a site called "Old Soaker," on lower Mount Sharp, Mars.

Image above: The network of cracks in this Martian rock slab called "Old Soaker" may have formed from the drying of a mud layer more than 3 billion years ago. The view spans about 3 feet (90 centimeters) left-to-right and combines three images taken by the MAHLI camera on the arm of NASA's Curiosity Mars rover. Image Credits: NASA/JPL-Caltech/MSSS.

If this interpretation holds up, these would be the first mud cracks -- technically called desiccation cracks -- confirmed by the Curiosity mission. They would be evidence that the ancient era when these sediments were deposited included some drying after wetter conditions. Curiosity has found evidence of ancient lakes in older, lower-lying rock layers and also in younger mudstone that is above Old Soaker.

"Even from a distance, we could see a pattern of four- and five-sided polygons that don't look like fractures we've seen previously with Curiosity," Stein said. "It looks like what you'd see beside the road where muddy ground has dried and cracked."

The cracked layer formed more than 3 billion years ago and was subsequently buried by other layers of sediment, all becoming stratified rock. Later, wind erosion stripped away the layers above Old Soaker. Material that had filled the cracks resisted erosion better than the mudstone around it, so the pattern from the cracking now appears as raised ridges.

Image above: This view of a Martian rock slab called "Old Soaker," which has a network of cracks that may have originated in drying mud, comes from the Mast Camera (Mastcam) on NASA's Curiosity Mars rover. It was taken on Dec. 20, 2016. The slab is about 4 feet long. Image Credits: NASA/JPL-Caltech/MSSS.

The team used Curiosity to examine the crack-filling material. Cracks that form at the surface, such as in drying mud, generally fill with windblown dust or sand. A different type of cracking with plentiful examples found by Curiosity occurs after sediments have hardened into rock. Pressure from accumulation of overlying sediments can cause underground fractures in the rock. These fractures generally have been filled by minerals delivered by groundwater circulating through the cracks, such as bright veins of calcium sulfate.

Both types of crack-filling material were found at Old Soaker. This may indicate multiple generations of fracturing: mud cracks first, with sediment accumulating in them, then a later episode of underground fracturing and vein forming.

"If these are indeed mud cracks, they fit well with the context of what we're seeing in the section of Mount Sharp Curiosity has been climbing for many months," said Curiosity Project Scientist Ashwin Vasavada of NASA's Jet Propulsion Laboratory in Pasadena. "The ancient lakes varied in depth and extent over time, and sometimes disappeared. We're seeing more evidence of dry intervals between what had been mostly a record of long-lived lakes."

Besides the cracks that are likely due to drying, other types of evidence observed in the area include sandstone layers interspersed with the mudstone layers, and the presence of a layering pattern called cross-bedding. This pattern can form where water was flowing more vigorously near the shore of a lake, or from windblown sediment during a dry episode.

Image above: A grid of small polygons on the Martian rock surface near the right edge of this view may have originated as cracks in drying mud more than 3 billion years ago. Multiple Dec. 20, 2016, images from the Mastcam on NASA's Curiosity Mars rover were combined for this view of a rock called "Squid Cove." Image Credits: NASA/JPL-Caltech/MSSS.

Scientists are continuing to analyze data acquired at the possible mud cracks and also watching for similar-looking sites. They want to check for clues not evident at Old Soaker, such as the cross-sectional shape of the cracks.

The rover has departed that site, heading uphill toward a future rock-drilling location. Rover engineers at JPL are determining the best way to resume use of the rover's drill, which began experiencing intermittent problems last month with the mechanism that moves the drill up and down during drilling.

Curiosity landed near Mount Sharp in 2012. It reached the base of the mountain in 2014 after successfully finding evidence on the surrounding plains that ancient Martian lakes offered conditions that would have been favorable for microbes if Mars has ever hosted life. Rock layers forming the base of Mount Sharp accumulated as sediment within ancient lakes billions of years ago.

On Mount Sharp, Curiosity is investigating how and when the habitable ancient conditions known from the mission's earlier findings evolved into conditions drier and less favorable for life. For more information about Curiosity, visit:

Images (mentioned), Text, Credits: NASA/Laurie Cantillo/Dwayne Brown/Martin Perez/JPL/Guy Webster.


Swiss Space Systems: bankruptcy confirmed

Swiss Space Systems (S3) logo.

Jan. 17, 2017

This is the end of Swiss Space Systems or S3. The latter withdrew its appeal in respect of an application for bankruptcy.

The bankruptcy of Swiss Space System Holding Ltd. (S3) is final. The Payerne-based company (VD, Switzerland) withdrew its appeal, the Vaud Cantonal Court said on Tuesday.

Pascal Jaussi, CEO & Founder of S3

As a result of this withdrawal, the president of the Court of Prosecution and Bankruptcy indicated that the bankruptcy of S3 took effect on Monday 16th January at 16:15, specifies the press release of the Cantonal Court.

On December 14th, the District Court of the Broye and Northern Waldensians declared the bankruptcy of the aerospace company, which is the subject of numerous lawsuits exceeding 7 million francs. S3 wanted to launch minisatellites from a shuttle carried on the back of an airplane. The company also planned to organize weightless flights.

Related articles:

S3 - Jaussi appeals to the Cantonal Court

The bankruptcy of S3 is pronounced

Engineer and founder of Swiss Space Systems (S3) violently assaulted

Image, Text, Credits: ATS / S3 / Aerospace / Roland Berga.


Successful Deep Space Maneuver for NASA’s OSIRIS-REx Spacecraft

NASA - OSIRIS-REx Mission patch.

Jan. 17, 2017

New tracking data confirms that NASA’s OSIRIS-REx spacecraft aced its first Deep Space Maneuver (DSM-1) on Dec. 28, 2016. The engine burn sets up the spacecraft for an Earth gravity assist this fall as it continues its two-year journey to the asteroid Bennu.

The large maneuver was the first using OSIRIS-REx’s main engines and resulted in a 964 miles per hour (431 meters per second) change in the vehicle’s velocity utilizing 780 pounds (354 kilograms) of fuel.

Deep Space Maneuver for NASA’s OSIRIS-REx Spacecraft

Tracking data from the Deep Space Network (DSN) confirmed the successful maneuver, and subsequent downlink of high-rate telemetry from the spacecraft shows that all subsystems performed as expected.

"DSM-1 was our first major trajectory change and first use of the main engines, so it’s good to have that under our belts and be on a safe trajectory to Bennu," said Arlin Bartels, deputy project manager at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

DSM-1 represents the first major, post-launch milestone for OSIRIS-REx. The significant change in trajectory from DSM-1 was necessary to put OSIRIS-REx on course for an encounter with Earth in September of this year.

A smaller trajectory correction maneuver will be executed on Wednesday, Jan. 18 to refine the course for the Earth flyby, during which Earth's gravity will bend the OSIRIS-REx trajectory and slinging it toward a rendezvous with the asteroid Bennu in the fall of 2018.

NASA’s Goddard Space Flight Center provides overall mission management, systems engineering and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission’s observation planning and processing. Lockheed Martin Space Systems in Denver built the spacecraft and is providing spacecraft flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program. NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the agency’s New Frontiers Program for its Science Mission Directorate in Washington.

OSIRIS-REx (Origins Spectral Interpretation Resource Identification Security Regolith Explorer):

Image, Text, Credits: University of Arizona/NASA's Goddard Space Flight Center, by Nancy Neal Jones/Karl Hille.


ALMA Starts Observing the Sun

ALMA - Atacama Large Millimeter/submillimeter Array logo.

17 January 2017

 ALMA observes a giant sunspot (1.25 millimetres)

New images taken with the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile have revealed otherwise invisible details of our Sun, including a new view of the dark, contorted centre of a sunspot that is nearly twice the diameter of the Earth. The images are the first ever made of the Sun with a facility where ESO is a partner. The results are an important expansion of the range of observations that can be used to probe the physics of our nearest star. The ALMA antennas had been carefully designed so they could image the Sun without being damaged by the intense heat of the focussed light.

Astronomers have harnessed ALMA's capabilities to image the millimetre-wavelength light emitted by the Sun’s chromosphere — the region that lies just above the photosphere, which forms the visible surface of the Sun. The solar campaign team, an international group of astronomers with members from Europe, North America and East Asia [1], produced the images as a demonstration of ALMA’s ability to study solar activity at longer wavelengths of light than are typically available to solar observatories on Earth.

ALMA observes a giant sunspot (3 millimetres)

Astronomers have studied the Sun and probed its dynamic surface and energetic atmosphere in many ways through the centuries. But, to achieve a fuller understanding, astronomers need to study it across the entire electromagnetic spectrum, including the millimetre and submillimetre portion that ALMA can observe.

Since the Sun is many billions of times brighter than the faint objects ALMA typically observes, the ALMA antennas were specially designed to allow them to image the Sun in exquisite detail using the technique of radio interferometry — and avoid damage from the intense heat of the focussed sunlight [2]. The result of this work is a series of images that demonstrate ALMA’s unique vision and ability to study our Sun.The data from the solar observing campaign are being released this week to the worldwide astronomical community for further study and analysis.

ALMA observes the full solar disc

The team observed an enormous sunspot at wavelengths of 1.25 millimetres and 3 millimetres using two of ALMA's receiver bands. The images reveal differences in temperature between parts of the Sun's chromosphere [3]. Understanding the heating and dynamics of the chromosphere are key areas of research that will be addressed in the future using ALMA.

Sunspots are transient features that occur in regions where the Sun's magnetic field is extremely concentrated and powerful. They are lower in temperature than the surrounding regions, which is why they appear relatively dark.

Image of the solar surface alongside a close-up view of a sunspot from ALMA

The difference in appearance between the two images is due to the different wavelengths of emitted light being observed. Observations at shorter wavelengths are able to probe deeper into the Sun, meaning the 1.25 millimetre images show a layer of the chromosphere that is deeper, and therefore closer to the photosphere, than those made at a wavelength of 3 millimetres.

Comparison of the solar disc in ultraviolet and millimetre wavelength light

ALMA is the first facility where ESO is a partner that allows astronomers to study the nearest star, our own Sun. All other existing and past ESO facilities need to be protected from the intense solar radiation to avoid damage. The new ALMA capabilities will expand the ESO community to include solar astronomers.

Sunspot seen in visible and millimetre wavelength light


[1] The ALMA Solar Campaign team includes: Shin'ichiro Asayama, East Asia ALMA Support Center, Tokyo, Japan; Miroslav Barta, Astronomical Institute of the Czech Academy of Sciences, Ondrejov, Czech Republic; Tim Bastian, National Radio Astronomy Observatory, USA; Roman Brajsa, Hvar Observatory, Faculty of Geodesy, University of Zagreb, Croatia; Bin Chen, New Jersey Institute of Technology, USA; Bart De Pontieu, LMSAL, USA; Gregory Fleishman, New Jersey Institute of Technology, USA; Dale Gary, New Jersey Institute of Technology, USA; Antonio Hales, Joint ALMA Observatory, Chile; Akihiko Hirota, Joint ALMA Observatory, Chile; Hugh Hudson, School of Physics and Astronomy, University of Glasgow, UK; Richard Hills, Cavendish Laboratory, Cambridge, UK; Kazumasa Iwai, National Institute of Information and Communications Technology, Japan; Sujin Kim, Korea Astronomy and Space Science Institute, Daejeon, Republic of Korea; Neil Philips, Joint ALMA Observatory, Chile; Tsuyoshi Sawada, Joint ALMA Observatory, Chile; Masumi Shimojo (interferometry lead), NAOJ, Tokyo, Japan; Giorgio Siringo, Joint ALMA Observatory, Chile; Ivica Skokic, Astronomical Institute of the Czech Academy of Sciences, Ondrejov, Czech Republic; Sven Wedemeyer, Institute of Theoretical Astrophysics, University of Oslo, Norway; Stephen White (single dish lead), AFRL, USA; Pavel Yagoubov, ESO, Garching, Germany and Yihua Yan, NAO, Chinese Academy of Sciences, Beijing, China.

[2] Indeed, this lesson has been learned the hard way: the Swedish–ESO Submillimetre Telescope (SEST) had a fire in its secondary mirror assembly after the telescope was accidentally pointed at the Sun.

[3] A map of the whole disc of the Sun was also made with a single ALMA antenna, using a technique called fast-scanning, at a wavelength of 1.25 millimetres. The accuracy and speed of observing with a single ALMA antenna makes it possible to produce a map of the entire solar disc in just a few minutes. These maps show the distribution of temperatures in the chromosphere over the whole disc at low spatial resolution and therefore complement the detailed interferometric images of individual regions of interest.

More information:

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of ESO, the U.S. National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI).

ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

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 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile. 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 a major partner in ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre European Extremely Large Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.


Photos of ALMA:

Atacama Large Millimeter/submillimeter Array (ALMA):

ESOcast 92 Light: ALMA Starts Observing the Sun:

Images, Videos, Text, Credits: ALMA/ESO/NAOJ/NRAO/NASA/SDO.

Best regards,