'Hairless' Neutron Stars

Credit: NASA's Marshall Space Flight Center, Illustration of the structure of a neutron star

These objects too can be described as “hairless” For astrophysicists neutron stars are extremely complex astronomical objects. Research conducted with the collaboration of SISSA and published in the journal Physical Review Letters demonstrates that in certain respects these stars can instead be described very simply and that they show similarities with black holes. In how many ways can one describe an object? Take an apple: by just looking at it we can easily estimate its weight, shape and colour but we are unable to describe it at any other level, for example, to evaluate thechemical composition of its flesh. Something similar also applies to astronomical objects: until today one of the challenges facing scientists was to describe neutron stars at the nuclear physics level. The matter these stars are made up of is in fact extremely complex, and several complicated equations of state have been proposed. However, to date there is no agreement as to which is the correct (or the best) one. A theoretical study conducted by SISSA (the International School for Advanced Studies of Trieste), in collaboration with Athens University, has demonstrated that neutron stars can also be described in relatively simple terms, by observing the structure of the space-time surrounding them. “Neutron stars are complex objects owing to the matter that composes them. We can picture them as enormous atomic nuclei with a radius of about ten kilometres”, explains Georgios Pappas, first author of the study carried out at SISSA. “A neutron star is what remains of the collapse of a massive star: the matter inside it is extremely dense and mostly consisting of neutrons”. “The nuclear physics required to understand the nature of the matter contained in these astronomical objects generally makes their description very complicated and difficult to formulate,” continues Pappas. “What we have demonstrated, by using numerical methods, is that there are properties that can provide a description of some aspects of neutron stars and the surrounding space-time in a simple manner, similar to the description used for black holes”. Black holes are truly unique objects: they have lost all matter and are only made up of space and time. Just like neutron stars they are the result of the collapse of a bigger star (in this case much bigger than the stars giving rise to neutron stars) and in the implosion all the matter has been swept away. “They are considered to be the most perfect objects in the Universe and the expression ‘hairless’ that was coined by John Archibald Wheeler to indicate their simplicity has become famous. According to our calculations even neutron stars can be depicted in a very similar manner”. Scientists use “multipole moments” as parameters to describe objects. The moments required to describe a black hole are two, mass and angular momentum (the speed at which it rotates around its axis). For neutron stars three moments are needed: mass, angular momentum and quadrupole moment, that is, a coefficient that describes the deformation of the object produced by its rotation. “Our calculations revealed two unexpected findings. First, we discovered that these three parameters are sufficient since higher levels moments are not independent and can be derived from the first three”, explains Pappas. “The second surprising finding is that the description based on these parameters is independent of the equation of equation of state, or rather: we don’t even need to know which is the equation of state”. In practice, we can have a description of a neutron star that is independent of the matter that forms it. “This has major implications”, concludes Pappas. “In fact, by using the data collected with astrophysical observations – for example, the radiation emitted by a neutron star, or information about objects gravitating around the star or other information – we can reconstruct the features of a neutron star”.Contacts and sources: Sissa Medialab, Effectively universal behavior of rotating neutron stars in general relativity makes them even simpler than their Newtonian counterparts Phys. Rev. Lett. George Pappas and Theocharis A. Apostolatos, http://journals.aps.org/prl/accepted/5507fYb3Ye211849920a70e877850e3cf8b5fbff7#abstract, The paper has just been published in the journal Physical Review Letters, where it also featured as an Editors’ Suggestion, among the most interesting papers of the latest issue. http://www.sissa.it/index.php/about/news/general/2905, Posted in: astronomy , Universe 'Source: Article

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King Of Galaxies Crowned, NGC 6872 Is 5 Times Larger Than Milky Way

Credit: NASA's Goddard Space Flight Center/ESO/JPL-Caltech/DSS

The spectacular barred spiral galaxy NGC 6872 has ranked among the biggest stellar systems for decades. Now a team of astronomers from the United States, Chile and Brazil has crowned it the largest-known spiral, based on archival data from NASA's Galaxy Evolution Explorer (GALEX) mission. GALEX has since been loaned to the California Institute of Technology in Pasadena, Calif. Measuring tip-to-tip across its two outsized spiral arms, NGC 6872 spans more than 522,000 light-years, making it more than five times the size of our Milky Way galaxy. This composite of the giant barred spiral galaxy NGC 6872 combines visible light images from the European Southern Observatory's Very Large Telescope with far-ultraviolet (1,528 angstroms) data from NASA's GALEX and 3.6-micron infrared data acquired by NASA's Spitzer Space Telescope. A previously unsuspected tidal dwarf galaxy candidate (circled) appears only in the ultraviolet, indicating the presence of many hot young stars. IC 4970, the small disk galaxy interacting with NGC 6872, is located above the spiral's central region. The spiral is 522,000 light-years across from the tip of one outstretched arm to the tip of the other, which makes it about 5 times the size of our home galaxy, the Milky Way. Images of lower resolution from the Digital Sky Survey were used to fill in marginal areas not covered by the other data. "Without GALEX's ability to detect the ultraviolet light of the youngest, hottest stars, we would never have recognized the full extent of this intriguing system," said lead scientist Rafael Eufrasio, a research assistant at NASA's Goddard Space Flight Center in Greenbelt, Md., and a doctoral student at Catholic University of America in Washington. He presented the findings Thursday at the American Astronomical Society meeting in Long Beach, Calif. The galaxy's unusual size and appearance stem from its interaction with a much smaller disk galaxy named IC 4970, which has only about one-fifth the mass of NGC 6872. The odd couple is located 212 million light-years from Earth in the southern constellation Pavo. Astronomers think large galaxies, including our own, grew through mergers and acquisitions -- assembling over billions of years by absorbing numerous smaller systems. Intriguingly, the gravitational interaction of NGC 6872 and IC 4970 may have done the opposite, spawning what may develop into a new small galaxy. "The northeastern arm of NGC 6872 is the most disturbed and is rippling with star formation, but at its far end, visible only in the ultraviolet, is an object that appears to be a tidal dwarf galaxy similar to those seen in other interacting systems," said team member Duilia de Mello, a professor of astronomy at Catholic University. The tidal dwarf candidate is brighter in the ultraviolet than other regions of the galaxy, a sign it bears a rich supply of hot young stars less than 200 million years old. The researchers studied the galaxy across the spectrum using archival data from the European Southern Observatory's Very Large Telescope, the Two Micron All Sky Survey, and NASA's Spitzer Space Telescope, as well as GALEX. By analyzing the distribution of energy by wavelength, the team uncovered a distinct pattern of stellar age along the galaxy's two prominent spiral arms. The youngest stars appear in the far end of the northwestern arm, within the tidal dwarf candidate, and stellar ages skew progressively older toward the galaxy's center. The southwestern arm displays the same pattern, which is likely connected to waves of star formation triggered by the

Credit: NASA's Goddard Space Flight Center, after C. Horellou (Onsala Space Observatory) and B. Koribalski (ATNF)

galactic encounter. Computer simulations of the collision between NGC 6872 and IC 4970 reproduce the basic features of the galaxies as we see them today. They indicate that IC 4970's closest encounter occurred 130 million years ago and that the smaller galaxy followed a path (dashed curve) close to the plane of the spiral's disk and in the same direction it rotates. A 2007 study by Cathy Horellou at Onsala Space Observatory in Sweden and Baerbel Koribalski of the Australia National Telescope Facility developed computer simulations of the collision that reproduced the overall appearance of the system as we see it today. According to the closest match, IC 4970 made its closest approach about 130 million years ago and followed a path that took it nearly along the plane of the spiral's disk in the same direction it rotates. The current study is consistent with this picture. As in all barred spirals, NGC 6872 contains a stellar bar component that transitions between the spiral arms and the galaxy's central regions. Measuring about 26,000 light-years in radius, or about twice the average length found in nearby barred spirals, it is a bar that befits a giant galaxy. The team found no sign of recent star formation along the bar, which indicates it formed at least a few billion years ago. Its aged stars provide a fossil record of the galaxy's stellar population before the encounter with IC 4970 stirred things up. "Understanding the structure and dynamics of nearby interacting systems like this one brings us a step closer to placing these events into their proper cosmological context, paving the way to decoding what we find in younger, more distant systems," said team member and Goddard astrophysicist Eli Dwek. The study also included Fernanda Urrutia-Viscarra and Claudia Mendes de Oliveira at the University of Sao Paulo in Brazil and Dimitri Gadotti at the European Southern Observatory in Santiago, Chile. The GALEX mission is led by the California Institute of Technology in Pasadena, which is responsible for science operations and data analysis. NASA's Jet Propulsion Laboratory, also in Pasadena, manages the mission and built the science instrument. GALEX was developed under NASA's Explorers Program managed by NASA's Goddard Space Flight Center. In May 2012, In May 2012, NASA announced it was loaning GALEX to Caltech, which continues spacecraft operations and data management using private funds. Contacts and sources: Francis Reddy, NASA's Goddard Space Flight Center, Paper: "Stars and Gas in the Very Large Interacting Galaxy NGC 6872." doi: 10.1051/0004-6361:20066023› "IC 4970 and NGC 6872: Galaxy Collision Switches on Black Hole" (12.10.2009), Source: Nano Patents And Innovations

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Millions of black holes spotted

A space telescope has added to its list of spectacular finds, spotting millions of supermassive black holes and blisteringly hot, "extreme" galaxies. The finds, by US space agency Nasa's Wide-Field Infrared Survey Explorer (Wise), once lay obscured behind dust. But Wise can see in wavelengths correlated with heat, seeing for the first time some of the brightest objects in the Universe. The haul will help astronomers work out how galaxies and black holes form. Black holes are regions of space where gravity is so powerful that not even light can escape. One way they can form is when huge stars collapse in on themselves. It is known that most large galaxies host black holes at their centres, sometimes feeding on nearby gas, dust and stars and sometimes spraying out enough energy to halt star formation altogether. How the two evolve together has remained a mystery, and the Wise data are already yielding some surprises. Wise gives astronomers what is currently a unique view on the cosmos, looking at wavelengths of light far beyond those we can see but giving information that we cannot get from wavelengths we can. The study is publisheda, Source: Sam Daily Times

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Eyes in the sky worldwide as Venus makes mark on sun

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Hindustan Times, Cape Canaveral, A rare celestial spectacle -- Transit of Venus -- the last for this century, unfolded in the morning sky all across the country today, enthralling the astro enthusiasts. Scientists and amateur astronomers alike celebrated the arrival of the Transit of Venus, peering up to the skies to watch a dark black spot slide over the surface of the Sun. The awesome spectacle was visible all over the country, including the national capital. However, a cloudy sky restricted its visibility from Delhi and some other parts of northern India. "This was the century's last Venus Transit," Nehru Planetarium Director N Rathnasree said. The event was visible at around 7 am, she said. Large projectors, pin hole cameras and telescopes were set up to help people see the celestial event unfold at the Planetarium, where a large number of people had gathered to see the rare event. "It is exciting to see such an event," said a Class X student Soumaya. "It is too good to resist. It is awesome," Nisha Gupta, a school teacher said, who had earlier seen the 2004 spectacle also. "The next Venus transit will happen after 105.5 years in 2117, making this a lifetime's event," Science Popularisation Association of Communicators and Educators (SPACE) Director C B Devgun said. From the Earth, this phenomenon is seen when the Venus passes between the Sun and the Earth. It occurs in intervals of 8, 121½, 8 and 105½ years, Devgun said. "The phenomenon should be seen only through solar filters, special solar glasses or with the help of pin hole cameras," Secretary of Planetary Society of India N Sri Raghunandan Kumar said. The last Transit of Venus occurred on June 8, 2004 and was visible across India. The passage of planet Venus across the face of Sun is once in a life time celestial event and many viewed it across the country. An official said today, "Over 5,000 people might have come and gone after seeing the celestial event in Chennai since morning. We made arrangements for the people to view the event thorough different telescopes," S. Soundarajaperumal, joint director, Birla Planetarium said. Special arrangements were made for the people to watch the transit of Venus as watching it with naked eyes is injurious. "While the school students enjoyed watching the event, Madras University students are doing their research," Soundarajaperumal said. See in pics The planet Venus made a slow transit across the face of the sun today, the last such passing that will be visible from Earth for 105 years. Transits of Venus happen in pairs, eight years apart, with more than a century between cycles. During the pass, Venus took the form of a small black dot slowly shifting across the northern hemisphere of the sun.Armchair astronomers watched the six-hour and 40-minute transit on the Internet, with dozens of websites offering live video from around the world. Closeup views from the Prescott Observatory in Arizona, fed into Slooh.com's webcast, showed a small solar flaring in the making just beneath Venus' sphere. Tuesday's transit, completing a 2004-2012 pair, began at 6.09 pm EDT (2209 GMT). Skywatchers on seven continents, including Antarctica, were able to see all or part of the transit. Even astronauts aboard the , International Space Station joined in the spectacle. "I've been planning this for a while," space station flight engineer Don Pettit said in a NASA interview. "I knew the transit of Venus would occur during my rotation, so I brought a solar filter with me." It's not all about pretty pictures. Several science experiments were planned, including studies that could help in the search for habitable planets beyond Earth. Telescopes, such as NASA's Kepler space telescope, are being used to find so-called extrasolar planets that pass in front of their parent stars, much like Venus passing by the sun. During the transit of Venus, astronomers planned to measure the planet's thick atmosphere in the hope of developing techniques to measure atmospheres around other planets. Studies of the atmosphere of Venus could also shed light on why Earth and Venus, which are almost exactly the same size and orbit approximately the same distance from the sun, are so different. Venus has a chokingly dense atmosphere, 100 times thicker than Earth's, that is mostly carbon dioxide, a greenhouse gas. Its surface temperature is a lead-melting 900 degrees Fahrenheit (480 degrees Celsius) and towering clouds of sulfuric acid jet around the planet at 220 miles per hour (355 kph) dousing it with acid rain. "Venus is known as the goddess of love, but it's not the type of relationship you'd want," an astronomer said on the Slooh.com webcast. "This is a look-but-don't-touch kind of relationship." Scientists are interested in learning more about Venus' climate in hopes of understanding changes in Earth's atmosphere. During previous transits of Venus, scientists were able to figure out the size of the solar system and the distance between the sun and the planets. Tuesday's transit is only the eighth since the invention of the telescope, and the last until December 10-11, 2117. It also is the first to take place with a spacecraft at Venus. Observations from Europe's Venus Express probe will be compared with those made by several ground and space-based telescopes, including NASA's Solar Dynamics Observatory, the joint US-European Solar and Heliospheric Observatory and Japan's Hinode spacecraft. (with inputs from PTI, Reuters) Source: Hindustan Times

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Nasa Telescope 'To Open New Window On Universe'

Nasa is launching a new telescope designed to study black holes and the sun that could "open a whole new window on the universe". The Nuclear Spectroscopic Telescope Array, or NuSTAR, is scheduled to launch no earlier than June 13 from Kwajalein Atoll in the central Pacific Ocean. Fiona Harrison, the NuSTAR principal investigator at the California Institute of Technology, said it will be the first space telescope to create focused images of high-energy cosmic X-rays. Source: The Coming Crisis, Image: flickr.com

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NASA develops a 'black hole' for stopping airborne cross-contamination

   Image Link Flickr

Fresh Plaza: You’ve likely heard of the mysterious entities known as “black holes” – NASA as well as many scientists worldwide share a theory that black holes in space literally constitute holes in the observable universe from which nothing can ever escape. Any matter that encounters them will be pulled inward by their massive gravity, destroyed and lost to the universe forever. Here on Earth and until recently, the black hole for destroying airborne cross-contamination in the food processing environment remained elusive using traditional technologies such as fiber filtration. “State of the art” HEPA-fiber filtration was developed for the America’s Nuclear Manhattan Project just before the end of WW II – and yes, some 66 years ago. Through the years, chemical applications and even toxic gases have been offered as solutions. We all know and  readily
accept state-of-the-art sanitizers and disinfectants to clean our floors, filter air, treat processing equipment, wash hands, etc. Unfortunately, it is instinctive to disregard what we cannot see, touch, smell or hear; including the ever present flow of airborne cross-contamination of microorganisms and organics as they fall into our products and onto our cleaned surfaces. The clear and present need within the food industry for a truly GREEN air sanitation solution – not relying on chemicals, random oxidants or filters – has finally been satisfied using a NASA-funded space technology. The technology is unique in providing no lower size limits, whereas former technologies such as HEPA are limited to measuring only particles that exceed 0.1 to 0.3 microns in size. There are no chemicals or toxic gases introduced, keeping operational costs low and protecting employee safety. Technical Notes: How does it work? Nano particle Titanium dioxide (TiO2) is the photocatalyst of choice. When TiO2 is irradiated with the UV photons surface bound hydroxyl radicals are formed. Surface bound hydroxyl radicals never become a gas like Ozone (O3). All the elements of the PCO reaction occur within its contained Reactor Bed. No byproducts are produced and no person exposed to adverse chemicals risks. The Photocatalytic reactor is self-cleaning by virtue of the reaction by-products (CO2 and water vapor generated by oxidized organic material on the catalyst surface). Contrary to Ultraviolet (UV) photons that require extended microbe contact times to be
an effective airborne killing device, this technology relies on collisions of microorganisms and organics with its surface bound hydroxyl radicals. Within this system, there can be as much as 177 Cubic Feet (ft.3) of active catalytic surface area that generates billions of hydroxyl radicals. These radicals are awaiting collision with microorganisms or organics that have been pulled into its reactor bed by its fan to be mineralized into CO2 and H2O vapor. Unclean air from the environment is transitioned through the reactor and is replaced with 99% clean air 24/7. This dilution effect drastically reduces microorganisms and organics from becoming airborne cross-contaminates. Contact:  John J. Hayman, Jr., KES Science & Technology, Inc., Phone: 770-427-6500 x 120, E-mail:  jhayman2@KesScience.com,   www.kesair.com,   Source: Fresh Plaza

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Birth of black hole ‘recorded’

The Asian Age, Washington, Astronomers have for the first time have produced a complete description of a black hole, a concentration of mass so dense that not even light can escape its powerful gravitational pull. Using several  telescopes, an international team yielded the most accurate measurements ever of the black hole’s mass and spin rate — in fact,  their  precise  measurements  allowed   them   to   reconstruct  the  history  of  the

   Image Link Flickr

object from its birth some six million years ago. “Because no other information can escape from a black hole, knowing its mass, spin, and electrical charge gives a complete description of it. The charge of this black hole is nearly zero, so measuring its mass and spin make our description complete,” said team leader Mark Reid of Harvard Smithsonian Centre for Astrophysics. Though Cygnus X-1 has been studied intensely since its discovery, previous attempts to measure its mass and spin suffered from lack of a precise measurement of its distance from earth. The team’s observations provided a distance of 6070 light years, while previous estimates had ranged from 5800-7800 light years Source: Birth of black hole ‘recorded’

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Life May Be Possible In Super Massive Black Holes: Cosmologist - Indian Express

Supermassive black holes are known to be absolutely uninhabitable and the most destructive force in space. But, conditions for life may exist inside them, claims a Russian cosmologist.Vyacheslav Dokuchaev, of Moscow's Institute for Nuclear Research of the Russian Academy of Sciences, has even said if life did exist inside the supermassive black holes, it would have evolved to become the most advanced civilisation in the  galaxy.  He   further

claimed that most advanced civilisation in the galaxy could already be living inside, the Daily Mail reports. Supermassive black holes are such powerful gravitational forces that they suck in everything around them, including light, and nothing that crosses their 'event horizon' is ever seen again. But, Dokuchaev, who specialises in studying those orbits and their dynamics, said existing evidence combined with new research throws up intriguing possibilities for certain types of black holes.Read Full: Life may be possible in supermassive black holes: Cosmologist - Indian Express

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Largest water reservour detected in space

Two teams of astronomers have discovered the largest and farthest reservoir of water ever detected in the universe, NASA said on Friday.The water, equivalent to 140 trillion times all the water in the world's ocean, surrounds a huge, feeding black hole, called a quasar, more than 12 billion light-years away. Tags: water, space, Sci-Tech, News, World, Читать далее, Source: Voice of Russia. 

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