Max Planck scientists discover a young and energetic neutron star with unusually
Pulsars are superlative cosmic beacons. These compact neutron stars rotate about their axes many times per second, emitting radio waves and gamma radiation into space. Using ingenious data analysis methods, researchers from the Max Planck Institutes for Gravitational Physics and for Radio Astronomy, in an international collaboration, dug a very special gamma-ray pulsar out of data from the Fermi Gamma-ray Space Telescope. The pulsar J1838-0537 is radio-quiet, very young, and, during the observation period, experienced the strongest rotation glitch ever observed for a gamma-ray-only pulsar.
Pure gamma-ray pulsars are difficult to identify because their characteristics, such as its sky position, the period of rotation and its change in time, are unknown. And astronomers can only determine their approximate position in the sky from the original Fermi observations. They must therefore check many combinations of these characteristics in a blind search, which requires a great deal of computing time. This is the only way of finding a hidden periodicity in the arrival times of the gamma-ray photons.
Even high-performance computers quickly reach their limit in this process. Therefore, the researchers used algorithms originally developed for the analysis of gravitational-wave data to conduct a particularly efficient hunt through the Fermi data. “By employing new optimal algorithms on our ATLAS computer cluster, we were able to identify many previously-missed signals,” says Bruce Allen, Director of the AEI.
Back in November 2011, Allen’s team announced the discovery of nine new Fermi gamma-ray pulsars, which had escaped all previous searches. Now the scientists have made a new extraordinary find with the same methods.
The name of the newly discovered pulsar – J1838-0537 – comes from its celestial coordinates. “The pulsar is, at 5,000 years of age, very young. It rotates about its own axis roughly seven times per second and its position in the sky is towards the Scutum constellation,” says Holger Pletsch, a scientist in Allen’s group and lead author of the study which has now been published. “After the discovery we were very surprised that the pulsar was initially only visible until September 2009. Then it seemed to suddenly disappear.”
Only a complex follow-up analysis enabled an international team led by Pletsch to solve the mystery of pulsar J1838-0537: it did not disappear, but experienced a sudden glitch after which it rotated 38 millionths of a Hertz faster than before. “This difference may appear negligibly small, but it’s the largest glitch ever measured for a pure gamma-ray pulsar,” explains Allen. And this behaviour has consequences.
“If the sudden frequency change is neglected, then after only eight hours, a complete rotation of the pulsar is lost in our counting, and we can no longer determine at which rotational phase the gamma-ray photons reach the detector aboard Fermi,” adds Pletsch. The “flashing” of the neutron star then disappears. If the researchers take the glitch into account and correct the change in rotation, the pulsar shows up again in the observational data.
The precise cause of the glitches observed in many young pulsars is unknown. Max-Planck-Institut für Radioastronomie Astronomers consider “star quakes” of the neutron star crust or interactions between the superfluid stellar interior and the crust to be possible explanations. “Detecting a large number of strong pulsar glitches makes it possible to learn more about the inner structure of these compact celestial bodies,” says Lucas Guillemot from the Max Planck Institute for Radio Astronomy in Bonn, the second author of the study. “This is a good example of the collaboration of two Max Planck institutes with complementary research foci,” says Michael Kramer, Director and Head of the Fundamental Physics in Radio Astronomy research group.
After the discovery in data from the Fermi satellite, the researchers pointed the radio telescope in Green Bank, West Virginia/USA at the celestial position of the gamma-ray pulsar. In an observation of almost two hours and by analysing a further, older, one-hour observation of the source they found no indications of pulsations in the radio range, indicating that J1838-0537 is a rare gamma-ray-only pulsar.
There were, however, noticeable overlays with observations of the High Energy Stereoscopic System (H.E.S.S.) in Namibia, which searches for very-high-energy gamma radiation from the depths of space. In a survey with H.E.S.S., astronomers found an extended source of this radiation near the now discovered pulsar, but have not yet been able to clarify its nature.
The discovery of the pulsar suggests that the H.E.S.S. source is a pulsar wind nebula. These are produced by particles moving at almost the speed of light, which the pulsar accelerates in its extremely strong magnetic field. Since the exact position of the pulsar is now known, H.E.S.S. can take this into account in the future and to make more precise measurements than before in this celestial region.
The ATLAS computer cluster of the Albert Einstein Institute has thus already assisted in the discovery of the tenth previously unknown gamma-ray pulsar; however, Allen’s team has meanwhile mobilised further computing capacity. “Since August 2011, our search has also been running on the distributed computing project Einstein@Home, which has computing power a factor of ten greater than the ATLAS cluster. We are very optimistic about finding more unusual gamma-ray pulsars in the Fermi data,” says Bruce Allen.
One goal of the expanded search is to discover the first gamma-ray-only pulsar with a rotation period in the millisecond range.
Holger J. Pletsch, L. Guillemot, B. Allen, M. Kramer et al.
PSR J1838-0537: Discovery of a young, energetic gamma-ray pulsar
The Astrophysical Journal Letters, gone to press
Source: NASA Mars
NASA's Mars Odyssey spacecraft has successfully adjusted its orbital location to be in a better position to provide prompt confirmation of the August landing of the Curiosity rover.
NASA’s Mars Science Laboratory spacecraft carrying Curiosity can send limited information directly to Earth as it enters Mars' atmosphere. Before the landing, Earth will set below the Martian horizon from the descending spacecraft's perspective, ending that direct route of communication. Odyssey will help to speed up the indirect communication process.(read more)
Source: USGS Newsroom
The 40-year Landsat record provides global coverage that shows large-scale human activities such as building cities and farming. The program is a sustained effort by the United States to provide direct societal benefits across a wide range of human endeavors, including human and environmental health, energy and water management, urban planning, disaster recovery and agriculture.
Landsat images from space are not merely pictures. They contain many layers of data collected at different points along the visible and invisible light spectrum. A single Landsat scene taken from 400 miles above Earth can accurately detail the condition of hundreds of thousands of acres of grassland, agricultural crops or forests. (read more)
A telescope launched July 11 aboard a NASA sounding rocket has captured the highest-resolution images ever taken of the sun's million-degree atmosphere called the corona. The clarity of the images can help scientists better understand the behavior of the solar atmosphere and its impacts on Earth's space environment.
"These revolutionary images of the sun demonstrate the key aspects of NASA's sounding rocket program, namely the training of the next generation of principal investigators, the development of new space technologies, and scientific advancements," said Barbara Giles, director for NASA's Heliophysics Division at NASA Headquarters in Washington.
Launched from White Sands Missile Range in New Mexico, the 58-foot-tall sounding rocket carried NASA's High Resolution Coronal Imager (Hi-C) telescope. Weighing 464 pounds, the 10-foot-long payload took 165 images during its brief 620-second flight. The telescope focused on a large active region on the sun with some images revealing the dynamic structure of the solar atmosphere in fine detail. These images were taken in the extreme ultraviolet wavelength. This higher energy wavelength of light is optimal for viewing the hot solar corona.
"We have an exceptional instrument and launched at the right time," said Jonathan Cirtain, senior heliophysicist at NASA's Marshall Space Flight Center in Huntsville, Ala. "Because of the intense solar activity we're seeing right now, we were able to clearly focus on a sizeable, active sunspot and achieve our imaging goals."
The telescope acquired data at a rate of roughly one image every 5 seconds. Its resolution is approximately five times more detailed than the Atmospheric Imaging Assembly (AIA) instrument flying aboard NASA's Solar Dynamics Observatory (SDO). For comparison, AIA can see structures on the sun's surface with the clarity of approximately 675 miles and observes the sun in 10 wavelengths of light. Hi-C can resolve features down to roughly 135 miles, but observed the sun in just one wavelength of light.
The high-resolution images were made possible because of a set of innovations on Hi-C's optics array. Hi-C's mirrors are approximately 9 1/2 inches across, roughly the same size as the SDO instrument's. The telescope includes some of the finest mirrors ever made for space-based instrumentation. The increase in resolution of the images captured by Hi-C is similar to making the transition in television viewing from a cathode ray tube TV to high definition TV.
Initially developed at Marshall, the final mirror configuration was completed with inputs from partners at the Smithsonian Astrophysical Observatory (SAO) in Cambridge, Mass., and a new manufacturing technique developed in coordination with L-3Com/Tinsley Laboratories of Richmond, Calif.
The high-quality optics were aligned to determine the spacing between the optics and the tilt of the mirror with extreme accuracy. Scientists and engineers from Marshall, SAO, and the University of Alabama in Huntsville worked to complete alignment of the mirrors, maintaining optic spacing to within a few ten-thousandths of an inch.
NASA's suborbital sounding rockets provide low-cost means to conduct space science and studies of Earth's upper atmosphere. In addition, they have proven to be a valuable test bed for new technologies for future satellites or probes to other planets.
Launched in February 2010, SDO is an advanced spacecraft studying the sun and its dynamic behavior. The spacecraft provides images with clarity 10 times better than high definition television and provides more comprehensive science data faster than any solar observing spacecraft in history.
Source: Universe Today
Artist’s concept that shows what astronomers believe
is an alien world just two-thirds the size of Earth.
Image credit: NASA/JPL-Caltech
Astronomers have detected what could be one of the smallest exoplanets found so far, just two-thirds the size of Earth. And, cosmically speaking, it’s in our neighborhood, at just 33 light-years away. But this planet, called UCF-1.01, is not a world most Earthlings would enjoy visiting: it likely is covered in magma.
“We have found strong evidence for a very small, very hot and very near planet with the help of the Spitzer Space Telescope,” said Kevin Stevenson from the University of Central Florida in Orlando, lead author of a new paper in The Astrophysical Journal. “Identifying nearby small planets such as UCF-1.01 may one day lead to their characterization using future instruments.” (read more)
Source: ESO Organisation Release eso1229
An international team of astronomers has observed the heart of a distant quasar with unprecedented sharpness, two million times finer than human vision. The observations, made by connecting the Atacama Pathfinder Experiment (APEX) telescope to two others on different continents for the first time, is a crucial step towards the dramatic scientific goal of the “Event Horizon Telescope” project: imaging the supermassive black holes at the centre of our own galaxy and others. (read more)
A team of astronomers using the NASA/ESA Hubble Space Telescope has discovered a fifth moon orbiting the icy dwarf planet Pluto. (read more)
Source: ESO Science Release eso1228
For the first time, dark galaxies — an early phase of galaxy formation, predicted by theory but unobserved until now — may have been spotted. These objects are essentially gas-rich galaxies without stars. Using ESO’s Very Large Telescope, an international team thinks they have detected these elusive objects by observing them glowing as they are illuminated by a quasar.(read more)
Astronauts return to Earth weakened and unsteady after weightlessness and radiation in space take their toll on the human body. New research now shows that the humble nematode worm adapts much better to spaceflight.(read more)
Astronomers have used the NASA/ESA Hubble Space Telescope to study some of the smallest and faintest galaxies in our cosmic neighbourhood. These galaxies are fossils of the early Universe: they have barely changed for 13 billion years. The discovery could help explain the so-called “missing satellite” problem, where only a handful of satellite galaxies have been found around the Milky Way, against the thousands that are predicted by theories. (read more)
The Vela C region, part of the Vela complex, by ESA’s Herschel space observatory.
Image credits: ESA/PACS & SPIRE Consortia, T. Hill, F. Motte, Laboratoire AIM
Paris-Saclay, CEA/IRFU – CNRS/INSU – Uni. Paris Diderot, HOBYS Key Programme Consortium
A beautiful blue butterfly flutters towards a nest of warm dust and gas, above an intricate network of cool filaments in this image of the Vela C region by ESA’s Herschel space observatory.(read more)
Action Sun at St Pauls Senior Girls School Dublin 12 - What's up for July 2012 from Jane Houston Jones
St Pauls Senior Girls National School in Greenhill’s Dublin 12 is just a few minutes’ walk from the house where I grew up. It was fortuitous to have the opportunity to carry out my third Action Sun for a school in this area.
On June 25th 47 young girls from third class, took part in building the sun. This was a very positive group all eager to get going and get busy. Streamers of orange and red paper flew through the air in vast amounts. In a short time the photosphere began to grow in the schools courtyard.
The activity of Action Sun supports the school curriculum in its art as it uses mixed media to create the sun. The program uses paint and paper to convey activity and explosive movement on the solar disc. Action Sun also supports primary school art as it enables children to use the characteristics of the materials to make structures and features on the solar disc. Making the sun in this way is both creative and explorative. Learning a little science through the arts facilitates the use of many kinds of intelligences. The learning process in the making is as valuable as the finished suns. Textures and spatial organisation also comes into the creation of this work. The girls at St Pauls School were very good at working as a group, helping each other out. They also made good decisions during the activity which showed they were an excellent team. This is kinesthetic learning, learning by doing.
Action Sun compliments science in the primary school curriculum on several levels. A short information talk in between making the suns features informs the children about our suns role in the solar system. We talk about the scale of the sun and the Earth. We talk about the energy of the sun and its function in relation to the other planets. The mini talks make sure that the children understand that the sun is our main source of heat and light. By building the sun the children learn by hands on investigation. The children literally explore the physical features of the sun with their hands in mini scale. A quick review of the evaluation sheets shows the quality of the learning. Several children not only drew sketches of the complex sun but also put in arrows to the different features and labelled them all correctly. The action of throwing the paper was very popular, signing their names was also a highlight and for some children carrying the sun into the hall was the stand out moment of the day.
When I look at the sun in my solar telescope I see a huge amount of detail and very often in the past I have shared that view with children. However it takes a long time to show this view to a large group as the sun presents as a small disc with tiny features. It is difficult for children to comprehend the enormous scale of our nearest star. I put Action Sun together to bridge that gap and help more people achieve some understanding of this wonderful star in safety with a big fun element.
The features of the sun itself were totally new to this young group, but at the end of the programme words like photosphere, chromosphere, filaments, prominences and sunspots were all a little more familiar. We closed our eyes at the end of the build and held our faces up to the sun to feel its heat and remind ourselves that it takes eight minutes for its light to get to us here on Earth, a 93 million mile smile. Building the sun took about 90 minutes. The 7.9 X 4.9 meter tarpaulin was pre prepared at home using four litres of matte black masonry paint. During the activity we used approx 3,500 individual pre cut pieces of crepe paper ,15 litres of washable PVA glue, 6 litres of yellow paint , 1 litre of red paint, plus the energy of forty seven eight and nine year old third class girls.
My thanks to Sarah Jayne Reid for setting up Action Sun at St Pauls and to Phil Curran for all her efforts prior to, during and post the build. Thanks to Ms Keating, Ms Daly and Principal Sr Maureen for their support during the activity. NASA Sun Earth Day bookmarks, posters and other educational material were provided to the teachers. The solar feature data for this Action Sun was an observation of the disc made from my PST earlier that morning. The Solar Dynamics Observatory website was pointed out to the girls so they could continue to watch the sun safely.
Source: NASA Hubble Space Telescope
Camelopardalis, or U Cam for short, is a star nearing the end of its life. As it begins to run low on fuel, it is becoming unstable. Every few thousand years, it coughs out a nearly spherical shell of gas as a layer of helium around its core begins to fuse. The gas ejected in the star’s latest eruption is clearly visible in this picture as a faint bubble of gas surrounding the star.(read more)
Source: Daily Galaxy
Physicists said Thursday the potential discovery of the "God particle" was a gateway to a new era that could see humanity unlock some of the universe's great mysteries including dark matter.
The discovery of the long-sought Higgs boson, an elusive particle thought to help explain why matter has mass, was hailed as a huge moment for science by physicists gathered in Australia, where CERN's findings were unveiled via videolink from Geneva at a landmark conference attended by hundreds of the field's top experts.
Scientists hailed the announcement, speculating that it could one day make light speed travel possible by "un-massing" objects or allow huge items to be launched into space by "switching off" the Higgs.* CERN scientist Albert de Roeck likened it to the discovery of electricity, when he said humanity could never have imagined its future applications.
"What's really important for the Higgs is that it explains how the world could be the way that it is in the first millionth of a second in the Big Bang," de Roeck told AFP.* "Can we apply it to something? At this moment my imagination is too small to do that."
Physicist Ray Volkas said "almost everybody" was hoping that, rather than fitting the so-called Standard Model of physics -- a theory explaining how particles fit together in the Universe -- the Higgs boson would prove to be "something a bit different".
"If that was the case that would point to all sorts of new physics, physics that might have something to do with dark matter," he said, referring to the hypothetical invisible matter thought to make up much of the universe.
British physicist Peter Higgs smiles at a press conference on July 4, at the European Organization for Nuclear Research (CERN) offices in Meyrin near Geneva. After a quest spanning nearly half a century, physicists said on July 4 they had found a new sub-atomic particle consistent with the Higgs boson which is believed to confer mass.
"It could be, for example, that the Higgs particle acts as a bridge between ordinary matter, which makes up atoms, and dark matter, which we know is a very important component of the universe."
"That would have really fantastic implications for understanding all of the matter in the universe, not just ordinary atoms," he added.* De Roeck said scrutinising the new particle and determining whether it supported something other than the Standard Model would be the next step for CERN scientists.
Clarification could be expected by the beginning of 2013; definitive proof that it fitted the Standard Model could take until 2015 when the LHC had more power and could harvest more data.
The LHC is due to go offline for a two-year refit in December that will see its firepower doubled to 14 trillion electronvolts -- a huge step forward in the search for new particles and clues about what holds them all together. De Roeck said he would find it a "little boring at the end if it turns out that this is just the Standard Model Higgs".
Instead, he was hoping it would be a "gateway or a portal to new physics, to new theories which are actually running nature" such as supersymmetry, which hypothesises that there are five different Higgs particles governing mass.
The hunt for Higgs -- the logical next step of which de Roeck said would be searching for, and eventually being able to produce, dark matter particles -- has already had huge benefits to medicine and technology.
Volkas said the Internet was born at CERN as a solution to high-volume data-sharing and other major spin-offs were likely to follow as physicists continued to "push the boundaries of pure science".