Электронная библиотека астронома-любителя. Книги по астрономии, телескопостроению, оптике.


Ru.Space.News:
Апрель 1998
ПнВтСрЧтПтСбВс
 
12345
6789101112
13141516171819
20212223242526
27282930
 

год:


  • Обзоры оружия и снаряжения
  • m31.spb.ru



  • AstroTop-100

    Яндекс цитирования


    0.032


    Архив RU.SPACE.NEWS за 24 апреля 1998


    Дата: 24 апреля 1998 (1998-04-24) От: Alexander Bondugin Тема: Chabrow Report To Be Available On The NASA Home Page Привет всем! Вот, свалилось из Internet... Michael Braukus Headquarters, Washington, DC April 23, 1998 (Phone: 202/358-1979) NOTE TO EDITORS: N98-29 CHABROW REPORT TO BE AVAILABLE ON THE NASA HOME PAGE The cost assessment and validation task force, an independent committee chaired by Jay Chabrow, has completed its report on the International Space Station. The complete report will be available electronically this afternoon. In September 1997, NASA Administrator Daniel S. Goldin asked Jay Chabrow to establish a task force for the independent review and assessment of costs, budgets and partnership performance on the International Space Station program and to provide advice and recommendations to the NASA Advisory Council. The objective of this activity was to provide advice and recommendations for cost-effective modifications to the present business structure and cost management practices of the program, and to determine the total cost over the life of the program. Media can review a copy of the report after noon EDT in the NASA newsrooms at NASA Headquarters, Washington, DC; Johnson Space Center, Houston, TX; Marshall Space Flight Center, Huntsville, AL; and Kennedy Space Center, FL. At 2 pm EDT the report will be available on the NASA Home Page at URL: http://www.nasa.gov/cavtf/index.html - end - Hа сегодня все, пока! =SANA=
    Дата: 24 апреля 1998 (1998-04-24) От: Alexander Bondugin Тема: Starry dream in Chile to become high-tech telescope reality [1/2] Привет всем! Вот, свалилось из Internet... University of North Carolina-Chapel Hill Contacts: Karen Stinneford, Mike McFarland, Karen Moon For immediate use: April 15, 1998 -- No. 335 Starry dream in Chile to become high-tech telescope reality By KAREN STINNEFORD, UNC-CH News Services CHAPEL HILL -- One small shovel of dirt, one giant leap for astronomers. When officials in Cerro Pachon, Chile, ceremonially break ground for the new SOAR telescope Friday (April 17), a 12-year-old dream among research astronomers at the University of North Carolina at Chapel Hill will become a reality. "We are so excited," said Dr. Wayne Christiansen, physics and astronomy professor and director of the Morehead Observatory. "It's finally going to happen." SOAR, the Southern Observatory for Astrophysical Research, is a state-of-the-art, lightweight, computer-controlled, 4-meter telescope that will sit atop Cerro Pachon, a 9,000-foot mountain in Chile's northern Andes. The $28-million research facility is being funded by four partners: UNC-CH, Michigan State University, the U.S. National Optical Astronomy Observatories (NOAO) and the country of Brazil. Construction should be completed by 2001. UNC-CH representatives who shovel Chilean earth Friday at 11:30 a.m. EDT will do more than turn over a little dirt. They literally will help usher in a new era of science. "The SOAR telescope will allow Carolina researchers and their collaborators to make significant contributions to the worldwide astronomy community well into the next century," said Chancellor Michael Hooker. "As a result, Carolina can better attract the best and brightest investigators and teachers, and greatly advance the cause of knowledge among scientists, students and the general public. "Our faculty have dreamed about SOAR for a long time, and we are deeply grateful for the assistance of Sen. Lauch Faircloth, Rep. David Price and the Cato and Goodman families in making that bold vision a reality." UNC-CH is contributing $8 million toward the project, $6 million of which came from the U.S. Department of Defense. Faircloth, R-N.C., led efforts by the N.C. congressional delegation to inform lawmakers about the project, which led to the first of two $3-million appropriations. Price also has been a strong supporter of SOAR. The rest of UNC-CH's share is coming from private donations. On Friday, representatives from UNC-CH, Michigan State, Brazil and NOAO will speak and erect flags from their institutions or country. UNC-CH physics and astronomy faculty attending include Dr. Thomas Clegg, department chair, and Drs. Bruce Carney, Charles Evans, Robert McMahan and Gerald Cecil. Cecil is on leave to NOAO in Tucson, Ariz., leading SOAR's scientific design team. Dr. Walter Bollenbacher from biology also will be part of the Carolina delegation. Carney will symbolically lift to the skies the lens from UNC-CH's first telescope, purchased in England by UNC President Joseph Caldwell in 1824. Seven years later in Chapel Hill, Caldwell oversaw construction of the first astronomical observatory at a U.S. university. SOAR will collect 3,400 times more light than that original telescope, Carney said. "We will detect objects well over a billion times fainter than the eye can see, and about 20 million times fainter than did that first telescope," Carney said. "So we can see dimmer objects and stars out to vastly greater distances, and, hence, further back in time than was possible in Caldwell's day." UNC-CH alumni connections will place Edgar and Samantha Cato of Charlotte and Leonard Goodman of New York City at the ceremony. The Cato and Goodman families contributed early and generously to SOAR. Accompanying Goodman will be his son, Stanley; daughter-in-law, Nancy; and grandchildren Yale and Pace. Besides supporting SOAR, the Goodman family is funding a laboratory in Phillips Hall to be named for Dr. Abraham Goodman. UNC-CH is recruiting an astronomical instrument builder to work in the lab developing instruments for SOAR and other telescopes. SOAR is not just your average telescope. Recent advances in equipment design and computer technology mean SOAR will allow astronomers to study and learn in ways they only dreamed possible, Christiansen said. For starters, SOAR's location is ideal. Based in the foothills of the 20,000-foot Andes mountain range, SOAR sits far away from smog, lights and other visual distractions generated by city life. The flowing offshore winds and lack of annual rainfall are just right for optimal viewing, Christiansen said. "The seeing is superb," he said. "In Chile, the center of the Milky Way galaxy passes right over your head. You can observe it for a much longer period of time, and your images aren't distorted as much by atmospheric effects." Chile is the best site in the Southern Hemisphere for viewing the Milky Way, the galaxy containing Earth and the other planets in our solar system, and the Magellanic Clouds, the closest neighboring galaxy. Besides offering an unfettered view of the universe, SOAR will be a technological marvel compared with today's telescopes, Christiansen said. SOAR will deliver the highest quality images possible with a large, ground-based telescope. A major advance will be SOAR's "quick change" instruments. Currently, 4-meter telescopes -- such as NOAO's Blanco telescope on the neighboring Chilean mountain, Cerro Tololo -- use equipment weighing tons. Depending on what type of equipment an astronomer needs to view the universe, such as infrared or visual cameras or spectographs, it can take a day or more to change settings and tools. In 1987, Christiansen flew to Chile to spend five days on the Blanco telescope, which had been set up, per his grant request submitted months earlier, for visual observation. Just before he left town, however, a supernova blew up, making national news. "Ironically, though, when I got to the observatory, which had the best equipment in the world to view this supernova, I couldn't even look at it," Christiansen said. "If we had pointed the telescope at the supernova, we would have fried the insides." The rare supernova was too bright for the Blanco telescope's sensitive visual equipment. Yet, changing equipment would have taken a day -- a big part of Christiansen's allotted time on the telescope. So Christiansen stuck with his original research plan and later viewed the supernova with a small telescope, like thousands of backyard astronomers. That scenario won't happen with SOAR. Thanks to improved design, lightweight equipment and computerized remote controls, SOAR can "quick change," allowing researchers to respond immediately to astronomical phenomena when they happen. "With SOAR, the minute something like a supernova comes up, we'll be all over it," Christiansen said. "We'll be able to react to unexpected events when they happen." Because it is so cumbersome to change equipment on telescopes like the Blanco, researchers now sign up for the telescope in several-day intervals. This isn't always the best use of time, for the researcher or the telescope. For example, Carney studies pulsating stars. The current system means he travels to Chile, collects five days worth of data and then returns to UNC-CH with reams of numbers to crunch. "It's an enormous amount of work for Bruce," Christiansen said. "Because of his area of expertise, what he really needs are several 15-minute intervals on the telescope throughout the evening -- not five days at a time. The current system won't allow that. SOAR will." SOAR's advanced computer system will allow UNC-CH researchers to study the skies from Chapel Hill. Because the university is guaranteed time on SOAR, researchers will create a list of projects and astronomical conditions, such as dark of the moon, needed to see them. When the right conditions happen, researchers will be notified to log onto computers in Chapel Hill to download data in real time. "We'll get our first cut at science right away and if things aren't going as expected, you can switch filters or make other changes on the fly," Christiansen said. "Once you've finished, you can get your data over the Internet or by airmail for further analysis. For the most part, we won't need to go to Chile." However, graduate students will be encouraged to visit the SOAR site. Not only will they gain valuable hands-on experience working with a state-of-the-art telescope, Christiansen said, but they'll have a chance to work alongside some of the world's most renowned astronomers. "It is a great experience when graduate students can work as colleagues with visiting scientists," he said. "These informal arrangements pay huge dividends for students, and we think it is a critical learning experience for them." SOAR will cost about $800,000 annually to operate, which NOAO has agreed to fund in exchange for time on the telescope. NOAO also will provide engineers and technicians on site to operate SOAR as directed by the project's partners. Brazil will contribute half of the $28 million construction costs; Michigan State will contribute $6 million. For its $8 million contribution, UNC-CH astronomers will use SOAR about 60 days each year. "This is time we control, time in which we set the priorities as a group," Christiansen said. There's an important public service component to SOAR, as well. Christiansen and his colleagues are looking at two exciting ways to involve North Carolina public-school teachers and students in the science of SOAR. First, Tar Heel teachers and students can view some of the same astronomical objects UNC-CH researchers see -- such as pulsating stars in the Milky Way galaxy and beyond, or newly discovered comets or asteroids, Christiansen said. UNC-CH astronomers will post interesting phenomena on a computer server in Chapel Hill; these images then can be seen in classrooms via Internet, he said. Second, science teachers and students can submit proposals for SOAR projects. UNC-CH researchers will review them and choose some; requested information will be downloaded to the school classroom, where it can be accessed by computer, Christiansen said. "We are committed to opening the world of science to our public schools in as many ways possible," Christiansen said. "We know, as educators, that having an opportunity to learn science hands-on only fuels a student's interest and desire to learn." Hа сегодня все, пока! =SANA=
    Дата: 24 апреля 1998 (1998-04-24) От: Alexander Bondugin Тема: Columbia University Unveils Supercomputer That Will Simulate Birth Of Subject: Columbia University Unveils Supercomputer That Will Simulate Birth Of Привет всем! Вот, свалилось из Internet... Office of Public Affairs Columbia University Contact: Bob Nelson rjn2@columbia.edu (212) 854-6580 April 21, 1998 Columbia Unveils Supercomputer That Will Simulate Birth Of The Universe Machine Capable Of 400 Billion Calculations Per Second To Explore Trillion-Degree Conditions That Existed As Time Began Physicists at Columbia University have constructed one of the world's fastest supercomputers, one that can perform 400 billion calculations per second to simulate the three-trillion-degree conditions that existed at the birth of the universe, when the components of atomic nuclei boiled free into a ultra-hot plasma. The supercomputer, dubbed QCDSP, is the latest in a series of relatively inexpensive parallel supercomputers now in use at universities around the world that have been built at Columbia, in what has become a burgeoning cottage industry for the physics department. Run in tandem with a sister machine capable of 600 billion operations per second Columbia is also finishing at Brookhaven National Laboratories on Long Island, the supercomputer will be capable of peak performance At trillion-calculation-per-second levels at a cost of less than $4 million, less than a tenth the typical $50 million price tag for a commercial supercomputer with that speed. Comparable, but far more expensive, machines are operating at the National Security Agency, Fort Meade, Md.; Sandia National Laboratories, Sandia, N.M., and at Tsukuba University in Japan. A billion floating-point operations, or adds and multiplies, per second is commonly called a gigaflop; a trillion such operations is a teraflop! The Columbia machine's vast computing power, which with others of its generation offers a 30-fold improvement over the previous generation of supercomputers, is needed to simulate the interactions between quarks and gluons, the tiny constituents of neutrons and protons, predicted by quantum chromodynamics (QCD) theory. Physicists believe that when normal matter is heated to three trillion degrees Fahrenheit, quarks and gluons -- never before observed outside an atomic nucleus -- boil free into an ultra-hot gas, called a quark-gluon plasma. The supercomputer will simulate this state, which scientists believe existed at the time of the Big Bang, perhaps 10 billion years ago, and hope to recreate at a particle accelerator under construction at Brookhaven. "These computers should be able to make major contributions to our understanding of the properties of the known strongly interacting particles, allowing accurate calculation of particle masses and decay rates," said Norman Christ, chairman and professor of physics and one of the project's principal investigators. "By building them ourselves, we're able to acquire world-class machines at a price within the level of funding available to U.S. science." The Columbia supercomputer will also be used to simulate interactions within atomic nuclei under other conditions, and could if necessary be programmed to carry out any of a number of highly complex calculations in fields such as weather forecasting, plasma physics and oil exploration. The only requirements in parallel supercomputing are that the problem be divisible among a large number of processors and that the data to be exchanged between these parts of the calculation be routed only between neighboring processors. Such huge computing power can be obtained at such a low cost because of a series of design decisions made by Professor Christ's research group, which pioneered the construction of highly parallel supercomputers dedicated to QCD calculations in 1982. The supercomputer alone incorporates 8,192 individual nodes that are linked together to undertake computations in parallel rather than sequentially. Each node includes a communications controller, designed by Columbia physicists and built to their specifications, and a digital signal processor (DSP) manufactured by Texas Instruments, both mounted on a circuit board with 2 megabytes of memory. A combination of the physics topic and the type of processor used led to the supercomputer's name: QCDSP. The Texas Instruments DSP is a unique choice of fast, inexpensive processor; no parallel computer with even a tenth as many of the processors has ever been constructed. Every node, or daughter board -- processor plus controller -- is a computer in its own right, with the computational performance of a Pentium PC but simplified to cost $80 and fit on a circuit board that measures 1-3/4 by 2-1/2 inches. A mother board holds 64 of the daughter boards, and a portable crate holds 8 mother boards. Crates can be cabled together using a four-dimensional mesh of communications wires to create even larger computers. Adding a host workstation to talk to the machine completes the computer, since all other required circuits are supplied in each crate. Smaller machines built by the physics department's staff are at work at other universities: a 50-gigaflop computer at Florida State University, a 6-gigaflop machine at Ohio State University and a 3-gigaflop machine at the University of Wuppertal in Germany, all built within the last year. Professor Christ said he would prefer to license the technology to a computer company that would build the machines, rather than tie up the department's staff with such projects. The other principal investigators in Professor Christ's research group are Robert Mawhinney, associate professor of physics, who has developed a UNIX-like operating system, called QOS, for the supercomputers, and Alan Gara, associate research scientist, who has played a leading role in designing the supercomputers. Pavlos Vranas, a postdoctoral fellow, has been instrumental in creating the code that carries out the actual physics calculations on the machines. One former undergraduate and a number present or former physics Ph.D. students have made major contributions to the project, in addition to collaborators at the Columbia University's Nevis Labs, Fermilab, Florida State University, Trinity College Dublin and Ohio State University. Quarks and gluons, also known as strongly interacting particles, are the least understood elements of the Standard Model, the prevailing physics theory that relates all known or predicted forces and particles. Quarks and gluons are so tightly bound that they have never been observed outside atomic nuclei. Physicists have thus turned to numerical simulations to study them, an approach that has demonstrated properties -- such as the impossibility of producing isolated quarks or gluons -- that could only be guessed from experiment. Creating a quark-gluon plasma is one of the principal goals of the Relativistic Heavy Ion Collider being constructed at Brookhaven and due for completion next year. Until experimental efforts to create this quark-gluon plasma are successful, large-scale numerical simulations are the only source of information about the new form of matter, Professor Christ said. The numerical approach to the study of nuclear forces was invented nearly 25 years ago and is now an active segment of theoretical particle physics. With the new Columbia and Tsukuba machines and a similar project in Rome, physicists expect dramatic progress in quantum chromodynamics theory. The increased capacity allows more complete and realistic QCD calculations and thus more precise tests of the theory and more accurate predictions of as-yet unobserved phenomena, such as the quark-gluon plasma. But even more exciting, Professor Christ said, is that this level of computer resources will allow computer experiments that explore new schemes for combining Einstein's relativity and quantum mechanics to create a unified physics theory, what some physicists call a "theory of everything." "Such new quantum field theories may show further unexpected behavior that could provide clues to the origin of the Standard Model and examples of what may lie beyond it," Professor Mawhinney said. Funding for the computers, and the Relativistic Heavy Ion Collider, has been provided by the Department of Energy. The Japanese Institute of Physical and Chemical Research, known by its Japanese acronym, RIKEN, has agreed to contribute $20 million to equip the Brookhaven collider to study high-energy protons, a key element in QCD theory. A description of the QCDSP can be found at http://phys.columbia.edu/~cqft. Hа сегодня все, пока! =SANA=
    Дата: 24 апреля 1998 (1998-04-24) От: Alexander Bondugin Тема: Astronomers Will Monitor A 'Diamond In The Sky' Привет всем! Вот, свалилось из Internet... News Service Iowa State University Contact: Steve Kawaler, Physics and Astronomy, (515) 294-9728 Skip Derra, News Service, (515) 294-4917 April 20, 1998 ASTRONOMERS WILL MONITOR A 'DIAMOND IN THE SKY' AMES, Iowa -- A team of about 50 astronomers will train their telescopes on a relatively close pulsating white dwarf star for the next three weeks with the goal of possibly finding a true gem in the sky. The astronomers, led by Steve Kawaler, an Iowa State University professor of physics and astronomy, will be monitoring a vibrating white dwarf star designated BPM37093, which is 17 light years from Earth. (A light year is the distance light travels in a year, about 6 trillion miles). The astronomers will make their observations using the Whole Earth Telescope and the Hubble Space Telescope from April 17 to May 4. Their findings could have an impact on the age of our galaxy and of the universe, and become the delight of gemologists worldwide. "We think BPM37093 is primarily made up of carbon and oxygen in a crystallized state," Kawaler says. "That would make it a diamond with a blue-green tint. It's estimated carat weight is 1034, or 10 billion trillion trillion. This truly could be a diamond in the sky." BPM37093 is a slowly cooling remnant of a star that once was a little more massive than our Sun. It resides in the constellation of Centaurus and is clearly viewable only from the Southern Hemisphere. Understanding the properties of white dwarf stars is important because nearly all stars will become eternally cooling white dwarf stars. Only the most massive stars will become fiery exploding supernovas. Being a white dwarf star, Kawaler said, BPM37093 has burned its nuclear fuel and all that remains is ash of carbon and oxygen. The only other known partially solid stars are neutron stars. By measuring the vibration frequency of BPM37093, astronomers can sneak a peak into its interior. Through stellar seismological techniques, Kawaler and the team of astronomers will attempt to ascertain the makeup of BPM37093. "The pulsations will tell us what's going on inside a star the same way earthquakes tell us about the inside of Earth," Kawaler said. "Each of the white dwarf's various brightness changes tells us something unique about the star's interior. It is very much like being able to hear and identify a violin and a bassoon in an orchestra concert." Crystallized white dwarf stars have been theorized to exist for 30 years, but because these stars are rare and exist under very extreme conditions, proving their existence has been a challenge. "Here on Earth, we will never be able to experience the types of pressures on the interiors of these stars," Kawaler said. "It's been a theory for 30 years, but it never has been tested. A white dwarf is a very, very dense star. One teaspoon of matter from these stars weigh as much as the New York Yankee infield -- about 500,000 grams." To make the critical measurements of the star, Kawaler's group will use a modern-day armada of Earth-based telescopes, which are part of the Whole Earth Telescope (WET). WET telescopes in South Africa, Brazil, Chile, New Zealand and Australia will be used in the observations. These measurements will be coupled with highly sensitive measurements from the orbiting Hubble Space Telescope. Kawaler is director of WET, which has partners at 22 observatories around Earth and allows 24-hour monitoring of stars. WET is headquartered at Iowa State University and is a program of the International Institute of Theoretical and Applied Physics. The core observation run will be April 20-29. During this time, the Hubble Space Telescope will turn its attention to BPM37093 and provide the astronomers with highly sensitive measurements in ultraviolet and optical wavelengths. Kawaler says the Hubble will allow astronomers to determine the precise pattern of vibrations on BPM37093, while the WET observations will provide the precise timing of the vibrations. The astronomers plan to continue to monitor the white dwarf star periodically for several years. They also hope to pin down how the crystallization happens and determine if BPM37093 is a "solid diamond or a diamond shell with oxygen snow," Kawaler said. "The material that is crystallizing is a mixture of different elements," Kawaler explained. "Different elements crystallize at different temperatures. Heavier elements like oxygen crystallize first, then the carbon will crystallize. If oxygen crystallizes in a gas of carbon, then those crystalline nuggets may sink to the center of the star -- as if it were snowing." The snowing effect would create additional energy not accounted for in some current white dwarf star models, Kawaler said. "But if the oxygen crystallizes and stays suspended, then you're getting crystallization without an additional energy source. If it snows, you'll have an oxygen crystalline core and a carbon crystal mantle. Sort of a diamond shell." And if the astronomers detect a shell with snow, then cool white dwarf stars (the oldest stars in this part of the galaxy) are older than previously thought. A pulsating white dwarf star that is snowing inside will be roughly 11 to 12 billion years old, rather than the currently estimated 9 billion years, Kawaler said. This finding will extend the lower limit of the age of the Milky Way galaxy and, in turn, extend the estimated age of the universe. Hа сегодня все, пока! =SANA=

    сайт служит астрономическому сообществу с 2005 года