Hubble breaks record for furthest supernova

Record-breaking supernova in the CANDELS Ultra Deep Survey

The NASA/ESA Hubble Space Telescope has broken the record in the quest to find the furthest supernova of the type used to measure cosmic distances. This supernova exploded more than 10 billion years ago (redshift 1.914), at a time the Universe was in its early formative years and stars were being born at a rapid rate. The supernova, designated SN UDS10Wil [1], belongs to a special class of exploding stars known as Type Ia supernovae. These bright beacons are prized by astronomers because they can be used as a yardstick for measuring cosmic distances, thereby yielding clues to the nature of dark

Record-breaking supernova in the CANDELS Ultra Deep Survey (compass and scale)

energy, the mysterious force accelerating the rate of expansion of the Universe. “This new distance record holder opens a window into the early Universe, offering important new insights into how these supernovae form,” said astronomer David O. Jones of The Johns Hopkins University in Baltimore, Md., lead author on the science paper detailing the discovery. “At that epoch, we can test theories about how reliable these detonations are for understanding the evolution of the Universe and its expansion.” One of the debates surrounding Type Ia supernovae is the nature of the fuse that ignites them. This latest discovery adds credence to one of two competing theories of how they explode. Although preliminary, the evidence favours the explosive merger of two burned out stars — small, dim, and dense stars known as white

The CANDELS Ultra Deep Survey (UDS)

dwarfs, the final state for stars like our Sun. The discovery was part of a three-year Hubble program called the CANDELS+CLASH Supernova Project, begun in 2010 [2]. This program aimed to survey faraway Type Ia supernovae to determine their distances and see if their behaviour has changed over the 13.8 billion years since the Big Bang, using the sharpness and versatility of Hubble’s Wide Field Camera 3. So far, CANDELS+CLASH has uncovered more than 100 supernovae of all types that exploded from 2.4 to over 10 billion years ago. The team has identified eight of these discoveries as Type Ia supernovae that exploded more than 9 billion years ago — including this new record-breaker, which, although only four percent older than the previous record holder, pushes the record roughly 350 million years further back in

Record-breaking supernova in the CANDELS Ultra Deep Survey: before, after, and difference

time [3]. The supernova team’s search technique involved taking multiple near-infrared images spaced roughly 50 days apart over the span of three years, looking for a supernova’s faint glow. After spotting SN UDS10Wil in December 2010, the CANDELS team then used the spectrometer on Hubble’s Wide Field Camera 3, along with the European Southern Observatory’s Very Large Telescope, to verify the supernova’s distance and to decode its light, hoping to find the unique signature of a Type Ia supernova. Finding remote supernovae opens up the possibility to measure the Universe’s accelerating expansion due to dark energy [4]. However, this is an area that is not fully understood — and nor are the origins of Type Ia supernovae. “This new result is a really exciting step forward in our study of supernovae and the distant Universe,” said team member Jens Hjorth of the Dark Cosmology Centre at the Niels Bohr Institute, University of Copenhagen. “We can begin to explore and understand the stars that cause these

After view of the record-breaking supernova in the CANDELS Ultra Deep Survey

violent explosions.” The team’s preliminary evidence shows a sharp decline in the rate of Type Ia supernova blasts between roughly 7.5 billion years ago and more than 10 billion years ago. This, combined with the discovery of such Type Ia supernovae so early in the Universe, suggests that the explosion mechanism is a merger between two white dwarfs. In the single white dwarf scenario — a pathway in which a white dwarf gradually feeds off a partnering normal star and explodes when it accretes too much mass — the rate of supernovae can be relatively high in the early Universe, because some of these systems can reach the point of explosion very quickly. The steep drop-off favours the double white dwarf mechanism, because it predicts that most stars in the early Universe are too young to become

Hubble in orbit

Type Ia supernovae. Knowing what triggers Type Ia supernovae will also show how quickly the Universe enriched itself with heavier elements, such as iron. These exploding stars produce about half of the iron in the Universe, the raw material for building planets, and life. The team’s results will appear in the 10 May 2013 issue of The Astrophysical Journal. Notes: [1] The supernova has been catalogued as SN UDS10Wil in the CANDEL-CLASH list. It has also been nicknamed SN Wilson, after the 28th U.S. president Woodrow Wilson. [2] This project searches for supernovae in near-infrared light and verifies their distances with spectroscopy. The supernova search draws on two large Hubble programs studying distant galaxies and galaxy clusters: the Cosmic Assembly Near-Infrared Deep Extragalactic Legacy Survey (CANDELS) and the Cluster Lensing and Supernova Survey with Hubble (CLASH). [3] The previous record holder was recently announced by a team that identified a supernova that exploded around 9 billion years ago (redshift 1.7). The paper was published in The Astrophysical Journal, available here:http://iopscience.iop.org/0004-637X/763/1/35 [4] It has been known since the late 1920s that distant galaxies appear to be moving away from us with a speed that is proportional to their distance. Edwin Hubble and Georges Lemaître were the first to infer that this implied the whole Universe is expanding. In 2011, the Nobel Prize in Physics was awarded to the teams of astronomers that discovered, using Type Ia supernovae, that this expansion is actually accelerating (ann11069) — Adam Riess of Johns Hopkins University, Saul Perlmutter of the University of California at Berkeley, and Brian Schmidt of the Australian National University in Canberra. This acceleration is attributed to dark energy, whose nature is unknown. Notes for editors: The Hubble Space Telescope is a project of international cooperation between ESA and NASA. The research is presented in a paper entitled “The Discovery of the Most Distant Known Type Ia Supernova at Redshift 1.914”, accepted for publication in 10 May 2013 issue of The Astrophysical Journal. The international team of astronomers in this study consists of: D. O. Jones (Johns Hopkins University, USA), S. A. Rodney (Johns Hopkins University, USA; Hubble Fellow), A. G. Riess (Johns Hopkins University, USA; Space Telescope Science Institute, USA), B. Mobasher (University of California, USA), T. Dahlen (Space Telescope Science Institute, USA), C. McCully (The State University of New Jersey, USA), T. F. Frederiksen (University of Copenhagen, Denmark), S. Casertano (Space Telescope Science Institute, USA), J. Hjorth (University of Copenhagen, Denmark), C. R. Keeton (The State University of New Jersey, USA), A. Koekemoer (Space Telescope Science Institute, USA), L. Strolger (Western Kentucky University, USA), T. G. Wiklind (Joint ALMA Observatory, ESO, Chile), P. Challis (Harvard/Smithsonian Center for Astrophysics, USA), O. Graur (Tel-Aviv University, Israel; American Museum of Natural History, USA), B. Hayden (University of Notre Dame, USA), B. Patel (The State University of New Jersey, USA), B. J. Weiner (University of Arizona, USA), A. V. Filippenko (University of California, USA), P. Garnavich (University of Notre Dame, USA), S. W. Jha (The State University of New Jersey, USA), R. P. Kirshner (Harvard/Smithsonian Center for Astrophysics, USA), S. M. Faber (University of California, USA), H. C. Ferguson (Space Telescope Science Institute, USA), N. A. Grogin (Space Telescope Science Institute, USA), and D. Kocevski (Harvard/Smithsonian Center for Astrophysics, USA). Links: Images of Hubble: http://www.spacetelescope.org/images/archive/category/spacecraft/, NASA press release: http://hubblesite.org/newscenter/archive/releases/2013/11/, CANDELS survey: http://candels.ucolick.org/, CLASH collaboration: http://www.stsci.edu/~postman/CLASH/, Research paper: http://www.spacetelescope.org/static/archives/releases/science_papers/heic1306.pdf, Images, Text, Credits: NASA, ESA, A. Riess, Z. Levay (STScI and JHU), and D. Jones and S. Rodney (JHU) / S. Faber (University of California, Santa Cruz), H. Ferguson (STScI), and the CANDELS team. Greetings, Orbiter.ch, Source: Orbiter.ch Space News

Read More........→April 07, 2013

Celestial Fireworks When Milky Way's Giant Black Hole Swallowed A Satellite Galaxy

Julie Turner, Vanderbilt University

These days the core of the Milky Way galaxy is a pretty tame place...cosmically speaking. The galactic black hole at the center is a sleeping giant. Existing stars are peacefully circling. Although conditions are favorable, there doesn’t even seem to be much new star formation going on. But there is growing evidence that several million years ago the galactic center was the site of all manner of celestial fireworks. A pair of assistant professors – Kelly Holley-Bockelmann at Vanderbilt and Tamara Bogdanović at Georgia Institute of Technology – have come up with an explanation that fits these “forensic” clues. Artist's illustration of a satellite galaxy on a collision course with the galactic black hole. Writing in the March 6 issue of the Monthly Notices of the Royal Astronomical Society, the astronomers describe how a single event – a violent collision and merger between the galactic black hole and an intermediate-sized black hole in one of the small “satellite galaxies” that circle the Milky Way – could have produced the features that point to a more violent past for the galactic core. “Tamara and I had just attended an astronomy conference in Aspen, Colorado, where several of these new observations were announced,” said Holley-Bockelmann. “It was January 2010 and a snow storm had closed the airport. We decided to rent a car to drive to Denver. As we drove through the storm, we pieced together the clues from the conference and realized that a single catastrophic event – the collision between two black holes about 10 million years ago - could explain all the new evidence.” The most dramatic of these extraordinary clues are the Fermi bubbles. These giant lobes of high-energy radiation - caused by particles moving nearly the speed of light - extend some 30,000 light years above and below the Milky Way center. If they were glowing in visible light they would fill about half of the night sky. But they radiate X-ray and gamma-ray light, so you need X-ray vision to see them. The discovery was reported by astronomers at the Harvard-Smithsonian Center for Astrophysics. Another puzzling characteristic of the GC, the astronomer’s abbreviation for the galactic center, is the fact that it contains the three most massive clusters of young stars in the entire galaxy. The Central, Arches and Quintuplet clusters each contain hundreds of young, hot stars that are much larger than the Sun. These stars typically burn out in “only” a few million years because of their extreme brightness, so there had to have been a relatively recent burst of star formation at the GC. The supermassive black hole that dominates the center of the Milky Way weighs in at about four million solar masses and is roughly 40 light seconds in diameter: only nine times the size of the sun. Such an object produces intense gravitational tides. So astronomers were surprised to discover a number of clumps of bright new stars closer than three lights years from the black hole’s maw. It wouldn’t be that surprising if the stars were being sucked into the black hole, but they show every sign of having formed in place. For this to happen, the clouds of dust and gas that they formed from must have been exceptionally dense: 10,000 times thicker than the other molecular clouds in the GC. While there is an excess of young hot stars in the galactic core, there is also a surprising dearth of older stars. Theoretical models predict that the density of old stars should increase as you move closer to the black hole. Instead, there are very few old stars found within several light years of the sleeping giant. When she got home from the conference, Holley-Bockelmann recruited Vanderbilt graduate student Meagan Langto work on the problem with them. With the assistance of Pau Amaro-Seoane from the Max Planck Institute for Gravitational Physics in Germany, Alberto Sesana from the Institut de Ciències de l'Espai in Spain, and Vanderbilt Research Assistant Professor Manodeep Sinha, they came up with a theoretical model that fits the observations and makes some testable predictions. The scenario began about 13 billion years ago, when the path of one of the smaller satellite galaxies orbiting the Milky Way is diverted so that it began drifting inward toward the core. According to a recent study, this may have happened dozens of times in the lifetime of the Milky Way. As the satellite galaxy – a collection of stars and gas with an intermediate-sized black hole with a mass equal to about 10,000 suns – spiraled in, most of its mass was gradually stripped away, finally leaving the black hole and a handful of gravitationally bound stars. About 10 million years ago, the stripped down core of the satellite galaxy finally reached the galactic center. When two black holes merge, they first go through an elaborate dance. So the smaller black hole would have circled the galactic black hole for several million years before it was ultimately consumed. As the smaller black hole circled closer and closer, it would have churned up the dust and gas in the vicinity and pushed enough material into the galactic black hole in the process to produce the Fermi bubbles. The violent gravitational tides produced by the process could easily have compressed the molecular clouds in the core to the super densities required to produce the young stars that are now located on the central black hole’s doorstep. In addition, the vigorous churning would have swept out the existing stars from the area surrounding the massive central black hole. In fact, the astronomer’s model predicts that the black holes’ merger dance should have flung a large number of the missing old stars out into the galaxy at hyper velocities, thus explaining the absence of old stars immediately around the super-massive black hole. “The gravitational pull of the satellite galaxy’s black hole could have carved nearly 1,000 stars out of the galactic center,” said Bogdanović. “Those stars should still be racing through space, about 10,000 light years away from their original orbits.” It should be possible to detect these stars with large surveys like the Sloan Digital Sky Survey because these stars would be traveling at much higher velocities than stars that have not undergone this type of interaction. So discovery of a large number of "high velocity stars" racing outward through the galaxy would strongly support the proposed scenario of the Milky Way and satellite galaxy merger. The research was supported by National Science Foundation Career Grant AST-0847696 and National Aviation and Space Administration grants NNX08AG74G and PF9-00061 as well as an NSF Graduate Research Fellowship. Contacts and sources: Vanderbilt Univerity, Citation: Monthly Notices of the Royal Astronomical Society, Source: Nano Patents And Innovations

Read More........→March 05, 2013

Clues to the Mysterious Origin of Cosmic RaysSN 1006

This remarkable image was created from pictures taken by different telescopes in space and on the ground. It shows the thousand-year-old remnant of the brilliant SN 1006 supernova, as seen in radio (red), X-ray (blue) and visible light (yellow).

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. The image on the left (bottom) shows the entire SN 1006 supernova remnant, as seen in radio (red), X-ray (blue) and visible light (yellow). The second panel, corresponding to the small square region marked at the left, is a NASA/ESA Hubble Space Telescope close up view of the remarkably narrow region of the shock front, where the material

from the  supernova is colliding with interstellar medium. The third panel shows how the integral field unit of the VIMOS instrument splits up the image into many small regions, the light from each of which is spread out into a spectrum of its component colors. When these spectra are analyzed, maps of the properties of the underlying object can be derived. The example shown here at the right is a map of one property of the gas (the width a spectral line), which is surprisingly variable, and implies, along with other indicators, the presence of very high-speed protons. Top image credit: 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. Bottom image credit: 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. Note: For more information, see Clues to the Mysterious Origin of Cosmic Rays, Source: Minex

Read More........→February 24, 2013

A spiral galaxy with a secret

Hubble view of M 106

The NASA/ESA Hubble Space Telescope – with a little help from an amateur astronomer – has produced one of the best views yet of nearby spiral galaxy Messier 106. Located a little over 20 million light-years away, practically a neighbour by cosmic standards, Messier 106 is one of the brightest and nearest spiral galaxies to our own. Despite its appearance, which looks much like countless other galaxies, Messier 106 hides a number of secrets. Thanks to this image, which combines data from Hubble with observations by amateur astronomers Robert Gendler and Jay GaBany, they are revealed as never before. At its heart, as in most spiral galaxies, is a supermassive black hole, but this one is particularly active. Unlike the black hole at the centre of the Milky Way, which pulls in wisps of gas only occasionally, Messier 106’s black hole is actively gobbling up material. As the gas spirals towards the black hole, it heats up and emits powerful radiation. Part of the emission from the centre of Messier 106 is produced by a process that is somewhat similar to that in a laser - although here the process produces bright microwave radiation [1]. The anomalous arms of M 106, As well as this microwave emission from Messier 106’s heart, the galaxy has another startling feature - instead of two spiral arms, it appears to have four. Although the second pair of arms can be seen in visible light images as ghostly wisps of gas, as in this image, they are even more prominent in observations made outside of the visible spectrum, such as those using X-ray or radio waves. Unlike the normal arms, these two extra arms are made up of hot gas rather than stars, and their origin remained unexplained until recently. Astronomers think that these, like the microwave emission from the galactic centre, are caused by the black hole at Messier 106’s heart, and so are a totally different phenomenon from the galaxy’s normal, star-filled arms. The extra arms appear to be an indirect result of jets of material produced by the violent churning of matter around the black hole. As these jets travel through the galactic matter they disrupt and heat up the surrounding gas, which in turn excites the denser gas in the galactic plane and causes it to glow brightly. This denser gas closer to the centre of the galaxy is tightly-bound, and so the arms appear to be straight. However, the looser disc gas further out is blown above or below the disc in the opposite direction from the jet, so that the gas curves out of the disc — producing the arching red arms seen here. Despite carrying his name, Messier 106 was neither discovered nor catalogued by the renowned 18th century astronomer Charles Messier. Discovered by his assistant, Pierre Méchain, the galaxy was never added to the catalogue in his lifetime. Along with six other objects discovered but not logged by the pair, Messier 106 was posthumously added to the Messier catalogue in the 20th century. Zoom on M 106 Amateur astronomer Robert Gendler retrieved archival Hubble images of M 106 to assemble a mosaic of the centre of the galaxy. He then used his own and fellow astrophotographer Jay GaBany’s observations of M 106 to combine with the Hubble data in areas where there was less coverage, and finally, to fill in the holes and gaps where no Hubble data existed. The centre of the galaxy is composed almost entirely of Hubble data taken by the Advanced Camera for Surveys, Wide Field Camera 3, and Wide Field and Planetary Camera 2 detectors. The outer spiral arms are predominantly HST data colourised with ground-based data taken by Gendler’s and GaBany’s 12.5-inch and 20-inch telescopes, located at very dark remote sites in New Mexico, USA. Gendler was a prizewinner in the recent Hubble’s Hidden Treasures image processing competition. Another prizewinner, André van der Hoeven, entered a different version of Messier 106, combining Hubble and NOAO data. Hubblecast 62: A spiral galaxy with a secret: http://www.spacetelescope.org/videos/heic1302a/, Notes: The Hubble Space Telescope is a project of international cooperation between ESA and NASA. [1] Lasers work when light stimulates emission of more light from a cloud of excited gas, with the original light in effect being amplified (the word laser is an acronym for light amplification by the stimulated emission of radiation). The centre of M106 harbours a similar phenomenon called a maser (short for microwave amplification by the stimulated emission of radiation), in which microwave radiation, which is at longer wavelengths than visible light, is emitted. Note that unlike man-made lasers, which are designed to produce a narrow beam, astronomical masers shine in all directions.Links:  Images of Hubble: http://www.spacetelescope.org/images/archive/category/spacecraft/, Robert Gendler: http://www.robgendlerastropics.com/, Image, Text, Credit: NASA, ESA, the Hubble Heritage Team (STScI/AURA), and R. Gendler (for the Hubble Heritage Team). Acknowledgment: J. GaBany, A van der Hoeven / Videos: NASA, ESA, L. Calçada / Digitzed Sky Survey 2, R. Gendler, J. GaBany, G. Bacon. Greetings, Orbiter.ch, Source: Orbiter.ch Space News

Read More........→February 09, 2013

Asteroid To Give Earth A Record Setting Close Shave On February 15

Credit: NASA

Talk about a close shave. On Feb. 15th an asteroid about half the size of a football field will fly past Earth only 17,200 miles above our planet's surface. There's no danger of a collision, but the space rock, designated 2012 DA14, has NASA's attention. Since regular sky surveys began in the 1990s, astronomers have never seen an object so big come so close to our planet. "This is a record-setting close approach," says Don Yeomans of NASA's Near Earth Object Program at JPL. "Since regular sky surveys began in the 1990s, we've never seen an object this big get so close to Earth." Earth's neighborhood is littered with asteroids of all shapes and sizes, ranging from fragments smaller than beach balls to mountainous rocks many kilometers wide. Many of these objects hail from the asteroid belt, while others may be corpses of long-dead, burnt out comets. NASA's Near-Earth Object Program helps find and keep track of them, especially the ones that come close to our planet. 2012 DA14 is a fairly typical near-Earth asteroid. It measures some 50 meters wide, neither very large nor very small, and is probably made of stone, as opposed to metal or ice. Yeomans estimates that an asteroid like 2012 DA14 flies past Earth, on average, every 40 years, yet actually strikes our planet only every 1200 years or so. The impact of a 50-meter asteroid is not cataclysmic--unless you happen to be underneath it. Yeomans points out that a similar-sized object formed the mile wide Meteor Crater in Arizona when it struck about 50,000 years ago. "That asteroid was made of iron," he says, "which made it an especially potent impactor." Also, in 1908, something about the size of 2012 DA14 exploded in the atmosphere above Siberia, leveling hundreds of

square miles of forest. Researchers are still studying the "Tunguska Event" for clues to the impacting object. "2012 DA14 will definitely not hit Earth," emphasizes Yeomans. "The orbit of the asteroid is known well enough to rule out an impact." In this oblique view, the path of near-Earth asteroid 2012 DA14 is seen passing close to Earth on Feb. 15, 2013. Even so, it will come interestingly close. NASA radars will be monitoring the space rock as it approaches Earth closer than many man-made satellites. Yeomans says the asteroid will thread the gap between low-Earth orbit, where the ISS and many Earth observation satellites are located, and the higher belt of geosynchronous satellites, which provide weather data and telecommunications. "The odds of an impact with a satellite are extremely remote," he says. Almost nothing orbits where DA14 will pass the Earth. NASA's Goldstone radar in the Mojave Desert is scheduled to ping 2012 DA14 almost every day from Feb. 16th through 20th. The echoes will not only pinpoint the orbit of the asteroid, allowing researchers to better predict future encounters, but also reveal physical characteristics such as size, spin, and reflectivity. A key outcome of the observing campaign will be a 3D radar map showing the space rock from all sides. During the hours around closest approach, the asteroid will brighten until it resembles a star of 8thmagnitude. Theoretically, that’s an easy target for backyard telescopes. The problem, points out Yeomans, is speed. “The asteroid will be racing across the sky, moving almost a full degree (or twice the width of a full Moon) every minute. That’s going to be hard to track.” Only the most experienced amateur astronomers are likely to succeed. Those who do might experience a tiny chill when they look at their images. That really was a close shave. For more information about 2012 DA14 and other asteroids of interest, visit NASA’s Near-Earth Object Program web site: http://neo.jpl.nasa.gov, Author: Dr. Tony Phillips |Production editor: Dr. Tony Phillips | Credit: Science@NASAAsteroid To Give , Source: Nano Patents And Innovations

Read More........→February 03, 2013

Vampire stars suck life from their neighbours

Star V838 Monocerotis's (V838 Mon) light echo, which is about six light years in diameter, is seen from the Hubble space telescope in this in this February 2004 handout photo released by NASA. It became the brightest star in the Milky Way Galaxy in January 2002 when its outer surface greatly expanded suddenly. 

An international team of astronomers has spotted a strange phenomena called as vampire stars, where a smaller companion star sucks matter off the surface of its larger neighbour using the very large telescope in Chile. They looked at what are known as O-type stars, which have very high temperature, mass and brightness. These stars have short and violent lives and play a key role in the evolution of galaxies. “These stars are absolute behemoths. They have 15 or more times the mass of our Sun and can be up to a million times brighter. These stars are so hot that they shine with a brilliant blue-white light and have surface temperatures over 30,000C,” the Daily Mail quoted Hugues Sana, from the University of Amsterdam, Netherlands, who is the lead author of the study, as saying. The astronomers studied a sample of 71 O-type single stars and stars in pairs (binaries) in six nearby young star clusters in the Milky Way. Most of the observations in their study were obtained using ESO telescopes, including the VLT. By analysing the light coming from these targets in greater detail than before, the team discovered that 75 per cent of all O-type stars exist inside binary systems, a higher proportion than previously thought, and the first precise determination of this number. Mergers between stars, which the team estimates will be the ultimate fate of around 20-30 per cent of O-type stars, are violent events. But even the comparatively gentle scenario of vampire stars, which accounts for a further 40-50 per cent of cases, has profound effects on how these stars evolve. Until now, astronomers mostly considered that closely-orbiting massive binary stars were the exception, something that was only needed to explain exotic phenomena such as X-ray binaries, double pulsars and black hole binaries. The new study shows that to properly interpret the Universe, this simplification cannot be made: these heavyweight double stars are not just common, their lives are fundamentally different from those of single stars. For instance, in the case of vampire stars, the smaller, lower-mass star is rejuvenated as it sucks the fresh hydrogen from its companion. Its mass will increase substantially and it will outlive its companion, surviving much longer than a single star of the same mass would. The victim star, meanwhile, is stripped of its envelope before it has a chance to become a luminous red super giant. Instead, its hot, blue core is exposed. As a result, the stellar population of a distant galaxy may appear to be much younger than it really is: both the rejuvenated vampire stars, and the diminished victim stars become hotter, and bluer in colour, mimicking the appearance of younger stars. Knowing the true proportion of interacting high-mass binary stars is therefore crucial to correctly characterise these faraway galaxies. The only information astronomers have on distant galaxies is from the light that reaches our telescopes. Without making assumptions about what is responsible for this light we cannot draw conclusions about the galaxy, such as how massive or how young it is. According to Sana, this study shows that the frequent assumption that most stars are single can lead to the wrong conclusions. Source: Hindustan Times, Image: flickr.com

Read More........→January 31, 2013

A hidden treasure in the Large Magellanic Cloud

LHA 120-N11 in the Large Magellanic Cloud

Nearly 200 000 light-years from Earth, the Large Magellanic Cloud, a satellite galaxy of the Milky Way, floats in space, in a long and slow dance around our galaxy. Vast clouds of gas within it slowly collapse to form new stars. In turn, these light up the gas clouds in a riot of colours, visible in this image from the NASA/ESA Hubble Space Telescope. The Large Magellanic Cloud (LMC) is ablaze with star-forming regions. From the Tarantula Nebula, the brightest stellar nursery in our cosmic neighbourhood, to LHA 120-N 11, part of which is featured in this Hubble image, the small and irregular galaxy is scattered with glowing nebulae, the most noticeable sign that new stars are being born. The LMC is in an ideal  position

Overview of the Large Magellanic Cloud (ground-based image)

for astronomers to study the phenomena surrounding star formation. It lies in a fortuitous location in the sky, far enough from the plane of the Milky Way that it is neither outshone by too many nearby stars, nor obscured by the dust in the Milky Way’s centre. It is also close enough to study in detail (less than a tenth of the distance of the Andromeda Galaxy, the closest spiral galaxy), and lies almost face-on to us [1], giving us a bird’s eye view. LHA 120-N 11 (known as N11 for short) is a particularly bright region of the LMC, consisting of several adjacent pockets of gas and star formation. NGC 1769 (in the centre of this image) and NGC 1763 (to the right, see heic1011) are among the brightest parts.  In the centre of this

Zoom into LHA 120-N11

image, a dark finger of dust blots out much of the light. While nebulae are mostly made of hydrogen, the simplest and most plentiful element in the Universe, dust clouds are home to heavier and more complex elements, which go on to form rocky planets like the Earth. Much finer than household dust (it is more like smoke), this interstellar dust consists of material expelled from previous generations of stars as they died. The data in this image were identified by Josh Lake, an astronomy teacher at Pomfret School in Connecticut, USA, in the Hubble’s Hidden Treasures image processing competition. The competition invited members of the public to dig out unreleased scientific data from Hubble’s vast archive, and to

Pan across LHA 120-N11

process them into stunning images. Josh Lake won first prize in the competition with an image contrasting the light from glowing hydrogen and nitrogen in N11. The image above combines the data he identified with additional exposures taken in blue, green and near infrared light. Notes: The Hubble Space Telescope is a project of international cooperation between ESA and NASA. [1] Although the Large Magellanic Cloud is generally classified as an irregular galaxy, it shares some features with spiral galaxies, including a clearly visible bar, and a single spiral-arm-like structure. It is thought that the LMC may be a small spiral galaxy that was pulled out of shape by the Milky Way. Links: Hidden Treasures: http://www.spacetelescope.org/hiddentreasures/, Josh Lake's image of N11: http://www.spacetelescope.org/projects/fits_liberator/fitsimages/josh_lake_ngc_1763/, ESA Hubble website: http://www.spacetelescope.org/, Images, Text, Credits: NASA, ESA. Acknowledgement: Josh Lake / ESO / Digitized Sky Survey 2. Acknowledgment: Davide De Martin/Video: NASA, ESA, Digitized Sky Survey 2 / Acknowledgement: Josh Lake. Best regards, Orbiter.ch, Source: Orbiter.ch Space News

Read More........→January 18, 2013

Supernova 'Mingus' could shed light on dark energy

Astronomers have spotted the most distant supernova ever seen. Nicknamed "Mingus", it was described at the 221st American Astronomical Society meeting in the US. These lightshows of dying stars have been seen since ancient times, but modern astronomers use details of their light to probe the Universe's secrets. Ten billion light-years distant, Mingus will help shed light on so-called dark energy, the force that appears to be speeding up cosmic expansion. Formally called SN SCP-0401, the supernova was something of a chance find in a survey carried out in part by the Supernova Cosmology Project (SCP) using the Hubble space telescope, first undertaken in 2004. But the data were simply not good enough to pin down what was seen. As David Rubin of the University of California, Berkeley, lead author on the study, told the AAS meeting, "for a sense of brightness, this supernova is about as bright as a firefly viewed from 3,000 miles away". Further news had to wait until astronauts installed the Wide Field Camera 3 on the Hubble telescope in 2009 and again trained it on the candidate, which had - in an SCP tradition of naming supernovae after composers - already been named after jazz musician Charles Mingus. 'Bit of history': What interests astronomers trying to find ever more distant Type 1a supernovae - distant both in space and in time - is the chance to compare them to better-known, more local supernovae. "We were able to watch these changes in brightness and spectral features for an event that lasted just a few weeks almost 10 billion years ago," said Saul Perlmutter, who leads the Supernova Cosmology Project. Prof Perlmutter shared the 2011 Nobel prize in physics for work with Type 1a supernovae that proved our Universe is speeding up in its expansion. Elucidating the mysterious force, "dark energy", which has been invoked as the cause of the expansion, will require careful study of supernovae all the way back to the epoch of the earliest stars. "We're seeing two-thirds of the way back to the beginning of the Universe, and we're getting a little bit of history where the physics of what makes a supernova explode have to all work out the same way there as they do near here," he told the meeting. Source: SAM Daily Times

Read More........→January 10, 2013

Nemesis Star: How The Planets Would Be Affected By Binary System

Credit; Wikipedia

A binary star is a star system consisting of two stars orbiting around their common center of mass. Binary stars are often detected optically, in which case they are called visual binaries. Many visual binaries have long orbital periods of several centuries or millennia and therefore have orbits which are uncertain or poorly known An international team of astrophysicists has shown that planetary systems with very distant binary stars are particularly susceptible to violent disruptions, more so than if they had stellar companions with tighter orbits around them. Unlike the Sun, many stars are members of binary star systems – where two stars orbit one another – and these stars' planetary systems can be altered by the gravity of their companion stars. The orbits of very distant or wide stellar companions often become very eccentric – ie. less circular – over time, driving the once-distant star into a plunging orbit that passes very close to the planets once per orbital period. The gravity of this close-passing companion can then wreak havoc on planetary systems, triggering planetary scatterings and even ejections. A simulated example of a binary star, where two bodies with similar mass orbit around a common barycenter in elliptic orbits This movie shows two simulations of planetary system disruption by galactic disturbances to wide binary stars. On the left is a zoomed-out view showing the orbit of a hypothetical 0.1 solar mass binary star around our own solar system with an initial orbital separation of 10,000 AU (1 AU is the distance between the Earth and the sun). On the right is a zoomed-in 

Credit: Nathan Kaib

view of the orbits of Jupiter, Saturn, Uranus, and Neptune. As the binary orbit becomes eccentric, this eventually excites the planetary orbits and Uranus and Neptune are both ejected. "The stellar orbits of wide binaries are very sensitive to disturbances from other passing stars as well as the tidal field of the Milky Way," said Nathan Kaib, lead author of a study published today in Nature describing the findings. "This causes their stellar orbits to constantly change their eccentricity – their degree of circularity. If a wide binary lasts long enough, it will eventually find itself with a very high orbital eccentricity at some point in its life." When a wide binary orbit becomes very eccentric, the two stars will pass very close together once per orbit on one side of the orbital ellipse, while being very far apart on the other side of the ellipse. This can have dire consequences for planets in these systems since the gravity of a close-passing star can radically change planetary orbits around the other star, causing planets to scatter off of one another and sometimes get ejected to interstellar space. Kaib, a postdoctoral fellow in the Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) and the Department of Physics and Astronomy at Northwestern University and a National Fellow in the Canadian Institute for Theoretical Astrophysics at the University of Toronto, conducted computer simulations of the process with Queen's University physics professor Martin Duncan and Sean N. Raymond, a researcher at the University of Bordeaux and the Centre national de la recherche scientifique in France. They added a a hypothetical wide binary companion to the Earth's solar system which eventually triggered at least one of four giant planets (Jupiter, Saturn, Uranus and Neptune) to be ejected in almost half of the simulations. "This process takes hundreds of millions of years if not billions of years to occur in these binaries. Consequently, planets in these systems initially form and evolve as if they orbited an isolated star," said Kaib, who will present the findings this week at the 221st meeting of the American Astronomical Society in Long Beach, California. "It is only much later that they begin to feel the effects of their companion star, which often times leads to disruption of the planetary system." "We also found that there is substantial evidence that this process occurs regularly in known extrasolar planetary systems," said Duncan. "Planets are believed to form on circular orbits, and they are only thought to attain highly eccentric orbits through powerful and/or violent perturbations. When we looked at the orbital eccentricities of planets that are known to reside in wide binaries, we found that they are statistically more eccentric than planets around isolated stars like our Sun. " The researchers believe this is a telltale signature of past planetary scattering events, and that those with eccentric orbits are often interpreted to be the survivors of system-wide instabilities. "The eccentric planetary orbits seen in these systems are essentially scars from past disruptions caused by the companion star," said Raymond. The researchers note that this observational signature could only be reproduced well when they assumed that the typical planetary system extends from its host star as much as 10 times the distance between the Earth and the Sun. Otherwise, the planetary system is too compact to be affected by even a stellar companion on a very eccentric orbit. "Recently, planets orbiting at wide distances around their host stars have been directly imaged. Our work predicts that such planets are common but have so far gone largely undetected," says Duncan. Contacts and sources: Sean Bettam, University of Toronto, Source: Nano Patents And Innovations

Read More........→January 09, 2013

40 Billion Times More Massive Than Our Sun: Record Setting Supermassive Black Hole

Credit: X-ray: NASA/CXC/Stanford/Hlavacek-Larrondo, J. et al; Optical: NASA/STScI; Radio: NSF/NRAO/VLA 

Some of the biggest black holes in the Universe may actually be even bigger than previously thought, according to a study using data from NASA's Chandra X-ray Observatory. Astronomers have long known about the class of the largest black holes, which they call "supermassive" black holes. Typically, these black holes, located at the centers of galaxies, have masses ranging between a few million and a few billion times that of our sun. This new analysis has looked at the brightest galaxies in a sample of 18 galaxy clusters, to target the largest black holes. The work suggests that at least ten of the galaxies contain an ultramassive black hole, weighing between 10 and 40 billion times the mass of the sun. Astronomers refer to black holes of this size as "ultramassive" black holes and only know of a few confirmed examples. "Our results show that there may be many more ultramassive black holes in the universe than previously thought," said study leader Julie Hlavacek-Larrondo of Stanford University and formerly of Cambridge University in the UK. The researchers estimated the masses of the black holes in the sample by using an established relationship between masses of black holes, and the amount of X-rays and radio waves they generate. This relationship, called the fundamental plane of black hole activity, fits the data on black holes with masses ranging from 10 solar masses to a billion solar masses. The black hole masses derived by Hlavacek-Larrondo and her colleagues were about ten times larger than those derived from standard relationships between black hole mass and the properties of their host galaxy. One of these relationships involves a correlation between the black hole mass and the infrared luminosity of the central region, or bulge, of the galaxy. "These results may mean we don't really understand how the very biggest black holes coexist with their host galaxies," said co-author Andrew Fabian of Cambridge University. "It looks like the behavior of these huge black holes has to differ from that of their less massive cousins in an important way." All of the potential ultramassive black holes found in this study lie in galaxies at the centers of massive galaxy clusters containing huge amounts of hot gas. Outbursts powered by the central black holes are needed to prevent this hot gas from cooling and forming enormous numbers of stars. To power 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. The extreme environment experienced by these galaxies may explain why the standard relations for estimating black hole masses based on the properties of the host galaxy do not apply. These results can only be confirmed by making detailed mass estimates of the black holes in this sample, by observing and modeling the motion of stars or gas in the vicinity of the black holes. Such a study has been carried out for the black hole in the center of the galaxy M87, the central galaxy in the Virgo Cluster, the nearest galaxy cluster to earth. The mass of M87's black hole, as estimated from the motion of the stars, is significantly higher than the estimate using infrared data, approximately matching the correction in black hole mass estimated by the authors of this Chandra study. "Our next step is to measure the mass of these monster black holes in a similar way to M87, and confirm they are ultramassive. I wouldn't be surprised if we end up finding the biggest black holes in the Universe," said Hlavacek-Larrondo. "If our results are confirmed, they will have important ramifications for understanding the formation and evolution of black holes across cosmic time." 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 in the July 2012 issue of The Monthly Notices of the Royal Astronomical Society. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations from Cambridge, Mass. For Chandra images, multimedia and related materials, visit: http://www.nasa.gov/chandra, For an additional interactive image, podcast, and video on the finding, visit:  http://chandra.si.edu, Source: Nano Patents And Innovations

Read More........→December 20, 2012

84 Million Stars and Counting

VISTA gigapixel mosaic of the central parts of the Milky Way

Using a whopping nine-gigapixel image from the VISTA infrared survey telescope at ESO’s Paranal Observatory, an international team of astronomers has created a catalogue of more than 84 million stars in the central parts of the Milky Way. This gigantic dataset contains more than ten times more stars than previous studies and is a major step forward for the understanding of our home galaxy. The image gives viewers an incredible, zoomable view of the central part of our galaxy. It is so large that, if printed with the resolution of a typical book, it would be 9 metres long and 7 metres tall.

Wide-field view of the Milky Way, showing the extent of a new VISTA gigapixel image

“By observing in detail the myriads of stars surrounding the centre of the Milky Way we can learn a lot more about the formation and evolution of not only our galaxy, but also spiral galaxies in general,” explains Roberto Saito (Pontificia Universidad Católica de Chile, Universidad de Valparaíso and The Milky Way Millennium Nucleus, Chile), lead author of the study.

Optical/infrared comparison of the central parts of the Milky Way

Most spiral galaxies, including our home galaxy the Milky Way, have a large concentration of ancient stars surrounding the centre that astronomers call the bulge. Understanding the formation and evolution of the Milky Way’s bulge is vital for understanding the galaxy as a whole. However, obtaining detailed observations of this region is not an easy task. “Observations of the bulge of the Milky Way are very hard because it is obscured by dust,” says Dante Minniti (Pontificia Universidad Catolica de Chile, Chile), co-author of the study. “To peer into the heart of the galaxy, we need to observe in infrared light, which is

Colour–magnitude diagram of the Galactic bulge

less affected by dust.”the The large mirror, wide field of view and very sensitive infrared detectors of ESO’s 4.1-metre Visible and Infrared Survey Telescope for Astronomy (VISTA) make it by far the best tool for this job. The team of astronomers is using data from the VISTA Variables in the Via Lactea programme (VVV) [1], one of six public surveys carried out with VISTA. The data have been used to create a monumental 108 200 by 81 500 pixel colour image containing nearly nine billion pixels. This is one of the biggest astronomical images ever produced. The team has now used these data to compile the largest catalogue of the central concentration of stars in the Milky Way ever created [2].

Annotated map of VISTA’s view of the centre of the Milky Way

To help analyse this huge catalogue the brightness of each star is plotted against its colour for about 84 million stars to create a colour–magnitude diagram. This plot contains more than ten times more stars than any previous study and it is the first time that this has been done for the entire bulge. Colour–magnitude diagrams are very valuable tools that are often used by astronomers to study the different physical properties of stars such as their temperatures, masses and ages [3]. “Each star occupies a particular spot in this diagram at any moment during its lifetime. Where it falls depends on how bright it is and how hot it is. Since the new data gives us a snapshot of all the stars in one go, we can now make a census of all the stars in this part of the Milky Way,” explains Dante Minniti. Video above: Infrared/visible light comparison of VISTA’s gigapixel view of the centre of the Milky Way. The new colour–magnitude diagram of the bulge contains a treasure trove of information about the structure and content of the Milky Way. One interesting result revealed in the new data is the large number of faint red dwarf stars. These are prime candidates around which to search for small exoplanets using the transit method [4]. “One of the other great things about the VVV survey is that it’s one of the ESO VISTA public surveys. This means that we’re making all the data publicly available through the ESO data archive, so we expect many other exciting results to come out of this great resource," concludes Roberto Saito. Notes: [1] The VISTA Variables in the Via Lactea (VVV) survey is an ESO public survey dedicated to scanning the southern plane and bulge of the Milky Way through five near-infrared filters. It started in 2010 and was granted a total of 1929 hours of observing time over a five-year period. Via Lactea is the Latin name for the Milky Way. [2] The image used in this work covers about 315 square degrees of the sky (a bit less than 1% of the entire sky) and observations were carried out using three different infrared filters. The catalogue lists the positions of the stars along with their measured brightnesses through the different filters. It contains about 173 million objects, of which about 84 million have been confirmed as stars. The other objects were either too faint or blended with their neighbours or affected by other artefacts, so that accurate measurements were not possible. Others were extended objects such as distant galaxies. The image used here required a huge amount of data processing, which was performed by Ignacio Toledo at the ALMA OSF. It corresponds to a pixel scale of 0.6 arcseconds per pixel, down-sampled from the original pixel scale of 0.34 arcseconds per pixel. [3] A colour–magnitude diagram is a graph that plots the apparent brightnesses of a set of objects against their colours. The colour is measured by comparing how bright objects look through different filters. It is similar to a Hertzsprung-Russell (HR) diagram but the latter plots luminosity (or absolute magnitude) rather than just apparent brightness and a knowledge of the distances of the stars plotted is also needed. [4] The transit method for finding planets searches for the small drop in brightness of a star that occurs when a planet passes in front of it and blocks some of its light. The small size of the red dwarf stars, typically with spectral types K and M, gives a greater relative drop in brightness when low-mass planets pass in front of them, making it easier to search for planets around them. More information: This research was presented in a paper “Milky Way Demographics with the VVV Survey I. The 84 Million Star Colour–Magnitude Diagram of the Galactic Bulge“ by R. K. Saito et al., which was published in the journal Astronomy & Astrophysics (A&A, 544, A147). The team is composed of R. K. Saito (Pontificia Universidad Católica de Chile, Santiago, Chile; Universidad de Valparaíso, Chile; The Milky Way Millennium Nucleus, Chile), D. Minniti (Pontificia Universidad Católica de Chile; Vatican Observatory), B. Dias (Universidade de São Paulo, Brazil), M. Hempel (Pontificia Universidad Católica de Chile), M. Rejkuba (ESO, Garching, Germany), J. Alonso-García (Pontificia Universidad Católica de Chile), B. Barbuy (Universidade de São Paulo), M. Catelan (Pontificia Universidad Católica de Chile), J. P. Emerson (Queen Mary University of London, United Kingdom), O. A. Gonzalez (ESO, Garching, Germany), P. W. Lucas (University of Hertfordshire, Hatfield, United Kingdom) and M. Zoccali (Pontificia Universidad Católica de Chile). The year 2012 marks the 50th anniversary of the founding of the European Southern Observatory (ESO). 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 a 40-metre-class European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”. Links: Research paper (A&A, 544, A147): http://www.aanda.org/10.1051/0004-6361/201219448, Photos of the VISTA telescope: http://www.eso.org/public/images/archive/search/?adv=&subject_name=Visible%20and%20Infrared%20Survey%20Telescope%20for%20Astronomy, Images taken with the VISTA telescope: http://www.eso.org/public/images/archive/search/?adv=&facility=30, Image, Text, Credits: ESO/VVV Consortium/Acknowledgement: Ignacio Toledo, Martin Kornmesser/Nick Risinger (skysurvey.org)/Videos: ESO/VVV Consortium/Nick Risinger (skysurvey.org)/Music: Delmo -- Acoustic (disasterpeace.com)/Acknowledgement: Ignacio Toledo, Martin Kornmesser., Greetings, Orbiter.ch, Source: Orbiter.ch Space News

Read More........→October 26, 2012

Dark Galaxies Spotted for the First Time

This deep image shows the region of the sky around the quasar HE0109-3518. The quasar is labeled with a red circle near the center of the image. The energetic radiation of the quasar makes dark galaxies glow, helping astronomers to understand the obscure early stages of galaxy formation. The faint images of the glow from 12 dark galaxies are labeled with blue circles. Dark galaxies are essentially devoid of stars, therefore they don’t emit any light that telescopes can catch. This makes them virtually impossible to observe unless they are illuminated by an external light source like a background quasar. This image combines observations from the Very Large Telescope, tuned to detect the fluorescent emissions produced by the quasar illuminating the dark galaxies, with color data from the Digitized Sky Survey 2. Photo credit: ESO, Digitized Sky Survey 2 and S. Cantalupo (UCSC), Source: Minsex

Read More........→September 25, 2012

NGC 2736 - The Pencil Nebula

The oddly shaped Pencil Nebula (NGC 2736) is pictured in this image from ESO’s La Silla Observatory in Chile. This nebula is a small part of a huge remnant left over after a supernova explosion that took place about 11,000 years ago. The image was produced by the Wide Field Imager on the MPG/ESO 2.2-meter telescope at ESO’s La Silla Observatory in Chile. Photo credit: ESO, A Celestial Witch’s Broom? Source: Minsex

Read More........→September 18, 2012

Scientist discovers plate tectonics on Mars

Image Link Wikimedia
The phenomenon of plate tectonics, previously thought to exist only on Earth also occurs beneath the surface of Mars, a scientist has claimed. A researcher from the University of California – Los Angeles found that the geological phenomenon, which involves the movement of huge crustal plates beneath a planet'ssurface, also exists on the red planet. "Mars is at a primitive stage of plate tectonics. It gives us a glimpse of how the early Earth may have looked and may help us understand how plate tectonics began on Earth," said An Yin, a UCLA professor of Earth and space sciences. Yin made the discovery during his analysis of satellite images from a NASA spacecraft known as THEMIS (Time History of Events and Macroscale Interactions during Substorms) and from the HIRISE (High Resolution Imaging Science Experiment) camera on NASA's Mars Reconnaissance Orbiter. He analysed about 100 satellite images - approximately a dozen were revealing of plate tectonics. Yin has conducted geologic research in the Himalayas and Tibet, where two of the Earth's seven major plates divide. "When I studied the satellite images from Mars, many of the features looked very much like fault systems I have seen in the Himalayas and Tibet, and in California as well, including the geomorphology," Yin said in a statement. Mars has a linear volcanic zone, which Yin said is a typical product of plate tectonics. "You don't see these features anywhere else on other planets in our solar system, other than Earth and Mars," said Yin. The study was published in the journal Lithosphere. The surface of Mars contains the longest and deepest system of canyons in our solar system, known as Valles Marineris. Scientists have wondered for four decades how it was formed. "I saw that the idea that it is just a big crack that opened up is incorrect. It is really a plate boundary, with horizontal motion. That is kind of shocking, but the evidence is quite clear," Yin added. "The shell is broken and is moving horizontally over a long distance. It is very similar to the Earth's Dead Sea fault system, which has also opened up and is moving horizontally," Yin said. "I don't quite understand why the plates are moving with such a large magnitude or what the rate of movement is; maybe Mars has a different form of plate tectonics. The rate is much slower than on Earth," Yin added. The Earth has a broken shell with seven major plates; pieces of the shell move, and one plate may move over another. Yin is doubtful that Mars has more than two plates. "We have been able to identify only the two plates," he said. "For the other areas on Mars, I think the chances are very, very small. I don't see any other major crack," Yin added. Source: Indian Express

Read More........→August 12, 2012

A Swarm of Dark Matter Around the Milky Way

These illustrations, taken from computer simulations, show a swarm of dark matter clumps around our Milky Way galaxy. Some of the dark-matter concentrations are massive enough to spark star formation. Dark matter is an invisible substance that accounts for most of the universe's mass. In the first panel, thousands of clumps of dark matter coexist with our Milky Way galaxy, shown in the center. The green blobs in the second panel are those dark-matter chunks massive enough to obtain gas from the intergalactic medium and trigger ongoing star formation, eventually creating dwarf galaxies. In the third panel, the red blobs are ultra-faint dwarf galaxies that stopped forming stars long ago. New Hubble Space Telescope observations of three of the puny galaxies reveal that star-making in these faint galaxies shut down more than 13 billion years ago. The synchronized shutdown is evidence that a global event, such as reionization, swept through the early universe. Reionization is a transitional phase in the early universe when the first stars burned off a fog of cold hydrogen. Popular theory predicts that most of the Milky Way's satellites contain few, if any, stars and are instead dominated by dark matter. More than a dozen small-fry galaxies have been found so far, all by the Sloan Digital Sky Survey, which scanned just a quarter of the sky. Illustration credit: J. Tumlinson (STScI), Note: For more information, see Hubble Unmasks Ghost Galaxies. Source: Minsex

Read More........→July 14, 2012

Black hole millions of times the size of our sun is 'hurtling' through space & scientists warn there could be many more

Astronomers have found a black hole several million times the size of our sun hurtling through space - and there could be many more of these deadly intergalactic missiles. It requires almost unimaginable force to move one - but scientists think that 'gravity waves', ripples in the fabric of space predicted by Einstein, could 'kick' black holes out of their home galaxies. The astronomers predict there could be 'many' hurtling black holes out there at - and that the objects, moving at milluions of miles per hour, would be completely invisible to our telescopes. The objects have such intense gravity they can tear stars apart. Supermassive black holes are thought to lurk at the centre of most galaxies, including our own Milky Way. ‘It's hard to believe that a supermassive black hole weighing millions of times the mass of the sun could be moved at all, let alone kicked out of a galaxy at enormous speed,’ said Francesca Civano of the Harvard-Smithsonian Center for Astrophysics. ‘But these new data support the idea that gravitational waves -- ripples in the fabric of space first predicted by Albert Einstein but never detected directly -- can exert an extremely powerful force.Source: The Coming Crisis

Read More........→June 18, 2012

The galaxy is doomed: NASA

The entire Milky Way is definitely going to collide with a neighbouring galaxy, NASA scientists say. But don't worry, Andromeda isn't set to reach the end of its collision course with our galaxy for another four billion years. "After nearly a century of speculation about the future destiny of Andromeda and our Milky Way, we at last have a clear picture of how events will unfold over the coming billions of years," said Sangmo Tony Sohn of the Space Telescope Science Institute in Baltimore, Md. The news comes from painstaking measurements from the Hubble space telescope that show Andromeda, also known as M31, is being pulled towards the Milky Way at a speed of 250,000 miles per hour because of gravity between the two galaxies and the invisible dark matter that surrounds them. Source: Sam Daily Times

Read More........→June 03, 2012

Black holes spinning faster and faster!!! Can be Dangerous??

Many giant black holes in the centre of galaxies are spinning faster than at any time in the history of the universe, and may have been set in motioncomparatively recently, new research shows. Dr Alejo Martinez-Sansigre of the University of Portsmouth and Professor Steve Rawlings of the University of Oxford used radio, optical and X-ray data to test their theoretical models of spinning black holes, and found the models stood up well for supermassive black holes with twin jets. Using the radio observations, the two astronomers were able to sample the population of black holes, deducing the spread of the power of the twin jets. By estimating how the black holes acquire material, they could then work out how quickly they might be spinning. The observations also give information on how the spins of supermassive black holes have evolved. In the distant past, say the researchers, practically all spun very slowly, whereas nowadays some have very high spins. So on average, they're spinning faster than ever before. It's the first time that the evolution of the spin of the supermassive black holeshas been closely described, and suggests that those that grow by swallowing matter will barely spin, while those that merge with other black holes will be left spinning rapidly. "The spin of black holes can tell you a lot about how they formed. Our results suggest that in recent times a large fraction of the most massive black holeshave somehow spun up," says Dr Martinez-Sansigre. "A likely explanation is that they have merged with other black holes of similar mass, which is a truly spectacular event, and the end product of this merger is a faster -spinning black hole." Later this decade, the team hopes to test the theory that these supermassiveblack holes have been set spinning relatively recently. "With so many collisions, we expect there to be a cosmic background of gravitational waves, something that will change the timing of the pulses of radio waves that we detect from the remnants of massive stars known as pulsars," says Professor Rawlings. "If we are right, this timing change should be picked up by the Square Kilometre Array, the giant radio observatory due to start operating in 2019."Source: The Ultimate Update

Read More........→May 19, 2012

Active Black Hole Squashes Star Formation

Minsex: The Herschel Space Observatory has shown that galaxies with the most powerful, active, supermassive black holes at their cores produce fewer stars than galaxies with less active black holes. Supermassive black holes are believed to reside in the hearts of all large galaxies. When gas falls upon these monsters, the materials are accelerated and heated around the black hole, releasing great torrents of energy. In the process, active black holes often generate colossal jets that blast out twin streams of heated matter. Inflows of gas into a galaxy also fuel the formation of new stars. In a new study of distant galaxies,Herschel helped show that star formation and black hole activity increase together, but only up to a point. Astronomers think that if an active black hole flares up too much, it starts spewing radiation that prevents raw material from coalescing into new stars. This artistically modified image of the local galaxy Arp 220, captured by the Hubble Space Telescope, helps illustrate the Herschel results. The bright core of the galaxy, paired with an overlaid artist's impression of jets emanating from it, indicate that the central black hole's activity is intensifying. As the active black hole continues to rev up, the rate of star formation will, in turn, be tamped down in thegalaxy. Astronomers want to further study how star formation and black hole activity are intertwined. Illustration credit: NASA/JPL-Caltech, Source; Minsex

Read More........→May 11, 2012

How planes of the future might look

Bisarbeat: Engineers have developed a concept plane which they believe, might be similar to passenger planes in 40 years time. However in the past futurologists have been wide of the mark, with predictions of jet packs, flying cars, and cities in the sky. Rajan Datar investigates whether, in the year 2050, we are really likely to be flying in transparent aeroplanes powered by solar energy. Apart from evolutionary improvements in conventional aircraft, revolutionary changes are possible when the "rules" are changed. This is possible when the configuration concept iteself is changed and when new roles or requirements are introduced. The following details give some idea of the range of concepts that have been studied over the past few years, some of which are currently being pursued by NASA and industry. Blended Wing Body  The BWB design is intended to improve airplane efficiency through a major change in the airframe configuration. The thick centerbody accommodates passengers and cargo without the extra wetted area and weight of a fuselage. Orginally designed as a very large aircraft with as many as 800 passengers, versions of the BWB has been designed with as few as 250 passengers and more conventional twin, podded engines. Joined Wing

The joined wing design was developed principally by Dr. Julian Wolkovitch in the 1980's as an efficient structural arrangement in which the horizontal tail was used as a sturcural support for the main wing as well as a stabilizing surface. It is currently being considered for application to high altitiude long endurance UAVs.

Oblique Flying Wing One of the most unusual concepts for passenger flight is the oblique wing, studied by Robert T. Jones at NASA from 1945 through the 1990s. Theoretical considerations suggest that the concept is well suited to low drag supersonic flight, while providing a structurally efficient means of achieving variable geometry. Airbus has revealed concept photos of its vision of what a passenger jet might look like in 2050. Now the futurists Airbus have turned their attention to inflight entertainment and the cabin experience for passengers in such jets.

The "biomimetic" frame of the Airbus Concept Plane, as it is known, is inspired by the super-lightweight bones of birds - though the company isn't quite sure yet what it might make this bone-inspired material from. Airbus cabin designer Tobias Mayer says it could be a 3D-printed - and largely hollow - titanium based material that the firm's parent, EADS, is becoming adept at manufacturing at its Additive Layer Manufacturing lab in Filton, UK. With a criss-cross structure it will supposedly allow some kind of bird-strike-resistant dimmable glass to be used as the exterior skin - giving passengers the astonishing ability to see everything outside.

Airbus envisages its plane having many different zones - because by 2050 budget air travel will have been abolished (along with economy seats) - and there'll be no more squeezing-as- many-seats-in-as-possible. "Passengers in 2050 could join an interactive conference, enjoy a game of virtual golf, or read the kids back home a bedtime story whilst watching the planet spread out beneath their feet,".

It doesn't end there. Morphing seats will sense the tension in your body using an intelligent neural network, allowing the seat to morph and conform to your body shape - and no matter how obese the population gets by 2050, these seats will be able to cope, Airbus promises. You'll get "vitamin and antioxidant-enriched air, mood lighting, aromatherapy and acupressure treatments".

New Roles and Requirements In addition to new configuration ideas, new roles and requirements for aircrafrt may lead to new aircraft concepts. Some of these are summarized below.Pacific Rim Travel As global commerce continues to increase, the need for passenger and cargo transportation grows as well. Many have speculated that growth in pacific rim travel may be the impetus for high speed aircraft development. The time required for flight from Los Angeles to Tokyo varies with cruise Mach number. (The somewhat facetious Mach 8 aircraft requires extra time to cool off before passengers can deplane.)

Supersonic transportation (Boeing High Speed Civil Transport Concept)

Ground Effect Cargo Tranport Concept

Vehicles designed for missions other than carrying passengers include military aircraft with new constraints on radar detection (low observables), very high altitude aircraft, such as the Helios solar powered aircraft intended for atmospheric science and earth observation studies, and vehicles such as the Proteus, designed as a communications platform.

Low Observables (B2 Bomber)

Autonomous Air Vehicles (Pathfinder: a prototype for Helios solar UAV)

Halo Autonomous Air Vehicle for Communications Services (an AeroSat)

Finally a new class of air vehicles intended to provide lower cost access to space is under study. The near-term future of such designs depends on the economic health of the commercial space enterprise and it presently appears that these concepts are not likely to be seen soon.

Access to Space

Conclusions: (1) Improved understanding and analysis capabilities permit continued improvement in aircraft designs (2) Exploiting new technologies can change the rules of the game, permitting very different solutions (3) New objectives and constraints may require unconventional configurations (4) Future progress requires unprecedented communication among aircraft designers, scientists, and computational specialists. Source: Bisarbeat

Read More........→May 02, 2012