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  1. Top | #1
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    Post Astronomical News

    Hello.
    I want to put this post to talk about latest news around astronomy, Its a new astronomical news page......
    I'll appreciate if u help me with this post........


    Thank u All
    ویرایش توسط planetstruck : 04-11-2011 در ساعت 09:36 AM دلیل: Adding words,Correcting Grammar points


  2. Top | #111
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          ephen Hawking's Curios

    Catching up on my blog reading today, I turned to "Cosmic Log," science writer Alan Boyle's must-read column on msnbc.com. Today's entry is titled "Stephen Hawking's curios explained." To celebrate Hawking's 70th birthday, the Science Museum in London is displaying the keepsakes he displays in his office and Alan reported on some of the individual objects and what they mean to Hawking.

    Scrolling down the page, I stopped at the third still image when I noticed a glass model of the planet Saturn that looked awfully familiar.

    "Donna!" I yelled across the room to Donna Stevens, the keeper of all things artistic at The Planetary Society. "Look at this! Is it what I think it is?"

    "OMG! It's our Cosmos Award!" Donna was excited. "I'll have to tell the artists who made it." And she ran to her computer to send them an e-mail.

    "Bill, come here!" I yelled again, this time to Bill Nye, who sits in the office next to mine. "You have to see this."

    "Look at that," Bill said, bending over my computer screen. "I think I've seen that planet somewhere before. Like, when we presented the Cosmos Award to Stephen in Cambridge. It was almost two years ago."

    Mat Kaplan, our Media Producer, looked over Bill's shoulder at the image on my computer screen. A quiet sort of person, Mat simply said, "Wow!"

    The glass model of Saturn represents the Cosmos Award for Public Presentation of Science, given by The Planetary Society to those who best exemplify the standards set by the Society's co-founder, Carl Sagan, and his landmark television series, "Cosmos." In honor of his many engagingly written science books and imaginative television programs, the 2010 Cosmos Award went to Stephen Hawking


    .



    10 Cosmos Award Ceremony

    Bijal Thakore, Bill Nye, Jim Bell, Dan Geraci, Ann Druyan, Neil deGrasse Tyson, and Louis Friedman with Stephen Hawking and the Cosmos Award

    . Credit: The Planetary Society
    source : planetary.org/

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  4. Top | #112
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    Astronomers Watch Delayed Broadcast of a Powerful Stellar Eruption
    Astronomers are watching a delayed broadcast of a spectacular outburst from the unstable, behemoth double-star system Eta Carinae, an event initially seen on Earth nearly 170 years ago.
    Dubbed the "Great Eruption," the outburst first caught the attention of sky watchers in 1837 and was observed through 1858. But astronomers didn't have sophisticated science instruments to accurately record the star system's petulant activity.





    Luckily for today's astronomers, some of the light from the eruption took an indirect path to Earth and is just arriving now, providing an opportunity to analyze the outburst in detail. The wayward light was heading in a different direction, away from our planet, when it bounced off dust clouds lingering far from the turbulent stars and was rerouted to Earth, an effect called a "light echo." Because of its longer path, the light reached Earth 170 years later than the light that arrived directly.
    The observations of Eta Carinae's light echo are providing new insight into the behavior of powerful massive stars on the brink of detonation. The views of the nearby erupting star reveal some unexpected results, which will force astronomers to modify physical models of the outburst.
    "When the eruption was seen on Earth 170 years ago, there were no cameras capable of recording the event," explained the study's leader, Armin Rest of the Space Telescope Science Institute in Baltimore, Md. "Everything astronomers have known to date about Eta Carinae's outburst is from eyewitness accounts. Modern observations with science instruments were made years after the eruption actually happened. It's as if nature has left behind a surveillance tape of the event, which we are now just beginning to watch. We can trace it year by year to see how the outburst changed."
    The team's paper will appear Feb. 16 in a letter to the journal Nature.
    Located 7,500 light-years from Earth, Eta Carinae is one of the largest and brightest star systems in our Milky Way galaxy. Although the chaotic duo is known for its petulant outbursts, the Great Eruption was the biggest ever observed. During the 20-year episode, Eta Carinae shed some 20 solar masses and became the second brightest star in the sky. Some of the outflow formed the system's twin giant lobes. Before the epic event, the stellar pair was 140 times heftier than our Sun.
    Because Eta Carinae is relatively nearby, astronomers have used a variety of telescopes, including the Hubble Space Telescope, to document its escapades. The team's study involved a mix of visible-light and spectroscopic observations from ground-based telescopes.
    The observations mark the first time astronomers have used spectroscopy to analyze a light echo from a star undergoing powerful recurring eruptions, though they have measured this unique phenomenon around exploding stars called supernovae. Spectroscopy captures a star's "fingerprints," providing details about its behavior, including the temperature and speed of the ejected material.
    The delayed broadcast is giving astronomers a unique look at the outburst and turning up some surprises. The turbulent star system does not behave like other stars of its class. Eta Carinae is a member of a stellar class called Luminous Blue Variables, large, extremely bright stars that are prone to periodic outbursts. The temperature of the outflow from Eta Carinae's central region, for example, is about 8,500 degrees Fahrenheit (5,000 Kelvin), which is much cooler than that of other erupting stars. "This star really seems to be an oddball," Rest said. "Now we have to go back to the models and see what has to change to actually produce what we are measuring."
    Rest's team first spotted the light echo while comparing visible-light observations he took of the stellar duo in 2010 and 2011 with the U.S. National Optical Astronomy Observatory's Blanco 4-meter telescope at the Cerro Tololo Inter-American Observatory (CTIO) in Chile. He obtained another set of CTIO observations taken in 2003 by astronomer Nathan Smith of the University of Arizona in Tucson, which helped him piece together the whole 20-year outburst.
    The images revealed light that seemed to dart through and illuminate a canyon of dust surrounding the doomed star system. "I was jumping up and down when I saw the light echo," said Rest, who has studied light echoes from powerful supernova blasts. "I didn't expect to see Eta Carinae's light echo because the eruption was so much fainter than a supernova explosion. We knew it probably wasn't material moving through space. To see something this close move across space would take decades of observations. We, however, saw the movement over a year's time. That's why we thought it was probably a light echo."
    Although the light in the images appears to move over time, it's really an optical illusion. Each flash of light is reaching Earth at a different time, like a person's voice echoing off the walls of a canyon.
    The team followed up its study with spectroscopic observations, using the Carnegie Institution of Washington's Magellan and du Pont telescopes at Las Campanas Observatory in Chile. That study helped the astronomers decode the light, revealing the outflow's speed and temperature. The observations showed that ejected material was moving at roughly 445,000 miles an hour (more than 700,000 kilometers an hour), which matches predictions.
    Rest's group monitored changes in the intensity of the light echo using the Las Cumbres Observatory Global Telescope Network's Faulkes Telescope South in Siding Spring, Australia. The team then compared those measurements with a plot astronomers in the 1800s made of the light brightening and dimming over the course of the 20-year eruption. The new measurements matched the signature of the 1843 peak in brightness.
    The team will continue to follow Eta Carinae because light from the outburst is still streaming to Earth. "We should see brightening again in six months from another increase in light that was seen in 1844," Rest said. "We hope to capture light from the outburst coming from different directions so that we can get a complete picture of the eruption."
    Rest's team consists of J.L. Prieto, Carnegie Observatories, Pasadena, Calif.; N.R. Walborn and H.E. Bond, Space Telescope Science Institute, Baltimore, Md.; N. Smith, Steward Observatory, University of Arizona, Tucson; F.B. Bianco and D.A. Howell, Las Cumbres Observatory Global Telescope Network, Goleta, Calif., and University of California, Santa Barbara; R. Chornock, R.J. Foley, and W. Fong, Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass.; D.L. Welch and B. Sinnott, McMaster University, Hamilton, Ontario; M.E. Huber, Johns Hopkins University, Baltimore, Md.; R.C. Smith, Cerro Tololo Inter-American Observatory, National Optical Astronomy Observatory, La Serena, Chile; I. Toledo, Atacama Large Millimeter Array (ALMA), Chile; D. Minniti, Pontifica Universidad Catolica, Santiago, Chile; and K. Mandel, Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass., and Imperial College London, U.K.


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  6. Top | #113
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          NASA's Hubble Spots a Relic from a Shredded Galaxy

    Astronomers using NASA's Hubble Space Telescope may have found evidence for a cluster of young, blue stars encircling one of the first intermediate-mass black holes ever discovered. Astronomers believe the black hole may once have been at the core of a now-disintegrated unseen dwarf galaxy. The discovery of the black hole and the possible star cluster has important implications for understanding the evolution of supermassive black holes and galaxies.
    Astronomers know how massive stars collapse to form black holes but it is not clear how supermassive black holes, which weigh billions of times the mass of our Sun, form in the cores of galaxies. One idea is that supermassive black holes may build up through the merger of smaller black holes.





    Sean Farrell of the Sydney Institute for Astronomy in Australia discovered a middleweight black hole in 2009 using the European Space Agency's XMM-Newton X-ray space telescope. Known as HLX-1 (Hyper-Luminous X-ray source 1), the black hole has an estimated weight of about 20,000 solar masses. It lies towards the edge of the galaxy ESO 243-49, 290 million light-years from Earth.
    Farrell then observed HLX-1 simultaneously with NASA's Swift observatory in X-ray and Hubble in near-infrared, optical, and ultraviolet wavelengths. The intensity and the color of the light may indicate the presence of a young, massive cluster of blue stars, 250 light-years across, encircling the black hole. Hubble can't resolve the stars individually because the suspected cluster is too far away. The brightness and color is consistent with other clusters of stars seen in other galaxies, but some of the light may be coming from the gaseous disk around the black hole.
    "Before this latest discovery we suspected that intermediate-mass black holes could exist, but now we understand where they may have come from," Farrell said. "The fact that there seems to be a very young cluster of stars indicates that the intermediate-mass black hole may have originated as the central black hole in a very-low-mass dwarf galaxy. The dwarf galaxy might then have been swallowed by the more massive galaxy, just as happens in our Milky Way."
    From the signature of the X-rays, Farrell's team knew there would be some blue light emitted from the high temperature of the hot gas in the disk swirling around the black hole. They couldn't account for the red light coming from the disk. It would have to be produced by a much cooler gas, and they concluded this would most likely come from stars. The next step was to build a model that added the glow from a population of stars. These models favor the presence of a young massive cluster of stars encircling the black hole, but this interpretation is not unique, so more observations are needed. In particular, the studies led by Roberto Soria of the Australian International Centre for Radio Astronomy Research, using data from Hubble and the ground-based Very Large Telescope, show variations in the brightness of the light that a star cluster couldn't cause. This indicates that irradiation of the disk itself might be the dominant source of visible light, rather than a massive star cluster.
    "What we can definitely say with our Hubble data is that we require both emission from an accretion disk and emission from a stellar population to explain the colors we see," said Farrell.
    Such young clusters of stars are commonly found inside galaxies like the host galaxy, but not outside the flattened starry disk, as found with HLX-1. One possible scenario is that the HLX-1 black hole was the central black hole in a dwarf galaxy. The larger host galaxy may then have captured the dwarf. In this conjecture, most of the dwarf's stars would have been stripped away through the collision between the galaxies. At the same time, new young stars would have formed in the encounter. The interaction that compressed the gas around the black hole would then have also triggered star formation.
    Farrell theorizes that the possible star cluster may be less than 200 million years old. This means that the bulk of the stars formed following the dwarf's collision with the larger galaxy. The age of the stars tells how long ago the two galaxies crashed into each other.
    Farrell proposed for more observations this year. The new findings are published in the February 15 issue of The Astrophysical Journal. Soria and his colleagues have published their alternative conclusions in the January 17 online issue of the Monthly Notices of the Royal Astronomical Society.


    source: www.hubblesite.org

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  8. Top | #114
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    Why ancient star clusters are all the same size

    15 February 2012 by Stephen Battersby

    Astronomical News-capture2-jpg

    Video:http://bcove.me/n3fyatd5

    Why do the universe's oldest star clusters tend to be roughly the same size? New simulations suggest it's because galaxy mergers destroyed the smaller ones.

    Globular star clusters are ancient, spherical blobs of stars. Most are a few hundred thousand times the mass of our sun. The scarcity of much bigger clusters is no surprise, as they would form more rarely – but why are there so few small ones?

    Using computer modelling, Diederik Kruijssen of the Max Planck Institute for Astrophysics in Garching, Germany, and his colleagues simulated the merger of two small galaxies. This process is thought to have been especially common in the early universe, when small structures were snowballing into larger ones.

    The collision compressed gas into dense knots, sparking star formation and creating many new globular clusters. At the same time it seeded destruction, as the gravity of these knots disrupted other clusters – both existing and new – passing nearby. Larger clusters survived, bound tightly by their own strong gravity, but the smaller ones were ripped apart.

    All large galaxies are thought to have formed in such mergers, so this might be why globular clusters everywhere fall into a narrow size range, says Kruijssen.

    From: Newscientist

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  10. Top | #115
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    NASA's Hubble Reveals a New Class of Extrasolar Planet



    Observations by NASA's Hubble Space Telescope have come up with a new class of planet, a waterworld enshrouded by a thick, steamy atmosphere. It's smaller than Uranus but larger than Earth.
    Zachory Berta of the Harvard-Smithsonian Center for Astrophysics (CfA) and colleagues made the observations of the planet GJ1214b.
    "GJ1214b is like no planet we know of," Berta said. "A huge fraction of its mass is made up of water."
    The ground-based MEarth Project, led by CfA's David Charbonneau, discovered GJ1214b in 2009. This super-Earth is about 2.7 times Earth's diameter and weighs almost seven times as much. It orbits a red-dwarf star every 38 hours at a distance of 1.3 million miles, giving it an estimated temperature of 450 degrees Fahrenheit.


    More Information

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  12. Top | #116
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    Ultra-fast Outflows Help Monster Black Holes Shape Their Galaxies


    A curious correlation between the mass of a galaxy's central black hole and the velocity of stars in a vast, roughly spherical structure known as its bulge has puzzled astronomers for years. An international team led by Francesco Tombesi at NASA's Goddard Space Flight Center in Greenbelt, Md., now has identified a new type of black-hole-driven outflow that appears to be both powerful enough and common enough to explain this link.

    Most big galaxies contain a central black hole weighing millions of times the sun's mass, but galaxies hosting more massive black holes also possess bulges that contain, on average, faster-moving stars. This link suggested some sort of feedback mechanism between a galaxy's black hole and its star-formation processes. Yet there was no adequate explanation for how a monster black hole's activity, which strongly affects a region several times larger than our solar system, could influence a galaxy's bulge, which encompasses regions roughly a million times larger.

    "This was a real conundrum. Everything was pointing to supermassive black holes as somehow driving this connection, but only now are we beginning to understand how they do it," Tombesi said.


    More Information

    From: www.NASA.gov

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  14. Top | #117
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    Dark Matter Core Defies Explanation in Hubble Image

    Astronomers observed what appeared to be a clump of dark matter left behind during a bizarre wreck between massive clusters of galaxies. The dark matter collected into a "dark core" containing far fewer galaxies than would be expected if the dark matter and galaxies hung together. Most of the galaxies apparently have sailed far away from the collision. This result could present a challenge to basic theories of dark matter, which predict that galaxies should be anchored to the invisible substance, even during the shock of a collision.


    The initial observations, made in 2007, were so unusual that astronomers shrugged them off as unreal, due to poor data. However, new results obtained in 2008 from NASA's Hubble Space Telescope confirm that dark matter and galaxies parted ways in the gigantic merging galaxy cluster called Abell 520, located 2.4 billion light-years away. Now, astronomers are left with the challenge of trying to explain dark matter's seemingly oddball behavior in this cluster.


    More Information


    From: www.hubblesite.org

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  16. Top | #118
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          NASA and CSA Robotic Operations Advance Satellite Servicing

    NASA's Robotic Refueling Mission (RRM) experiment aboard the International Space Station has demonstrated remotely controlled robots and specialized tools can perform precise satellite-servicing tasks in space. The project marks a milestone in the use of the space station as a technology test bed.

    "We and our partners are making important technological breakthroughs," NASA Administrator Charles Bolden said. "As we move ahead toward reaching our exploration goals, we will realize even more benefits from humans and robots working together in space."

    The Canadian Space Agency's (CSA) robotic handyman, Dextre, successfully completed the tasks March 7-9 on the space station's external RRM module, designed to demonstrate the tools, technologies and techniques needed to robotically refuel and repair satellites.


    On March 7, 2012, the Robotic Refueling Mission team got its first chance to put its payload to the test in orbit. For the next three days, the teams at NASA Goddard's Robotic Lab and Satellite Servicing Center worked with Johnson Space Center robotic operators and carefully moved the International Space Station's robotic arm to manipulate tools on RRM. (Video Credit: NASA's Goddard Space Flight Center)

    "The Hubble servicing missions taught us the importance and value of getting innovative, cutting-edge technologies to orbit quickly to deliver great results," said Frank Cepollina, a veteran leader of five Hubble Space Telescope servicing missions and associate director of the Satellite Servicing Capabilities Office (SSCO) at NASA's Goddard Space Flight Center in Greenbelt, Md. "The impact of the space station as a useful technology test bed cannot be overstated. Fresh satellite-servicing technologies will be demonstrated in a real space environment within months instead of years. This is huge. It represents real progress in space technology advancement."

    Before a satellite leaves the ground, technicians fill its fuel tank through a valve that is sealed, covered and designed never to be accessed again. The RRM experiment demonstrates a remote-controlled robot can remove these barriers and refuel such satellites in space.


    The Robotic Refueling Mission (RRM) module on the International Space Station before it was installed on its permanent platform. RRM will demonstrate robotic servicing technology and lay the foundation for future missions. (Image credit: NASA)
    › View larger image


    On July 12, 2011, spacewalking astronauts Mike Fossum and Ron Garan successfully transferred the Robotic Refueling Mission module from the Atlantis shuttle cargo bay to a temporary platform on the International Space Station's Dextre robot. (Image credit: NASA)
    › View larger image
    Dextre successfully retrieved and inspected RRM tools, released safety launch locks on tool adapters, and used an RRM tool to cut extremely thin satellite lock wire. These operations represent the first use of RRM tools in orbit and Dextre's first participation in a research and development project.

    RRM was developed by SSCO and is a joint effort between NASA and CSA. During the next two years, RRM and Dextre will conduct several servicing tasks using RRM tools on satellite parts and interfaces inside and covering the cube-shaped RRM module.

    NASA expects the RRM results to reduce the risks associated with satellite servicing. It will encourage future robotic servicing missions by laying the foundation for them. Such future missions could include the repair, refueling and repositioning of orbiting satellites.

    "We are especially grateful to CSA for their collaboration on this venture," Cepollina said. "CSA has played a pivotal role in the development of space robotics, from the early days of the space shuttle to the work they are doing with Dextre on space station."

    During the three-day RRM Gas Fittings Removal task, the 12-foot (3.7-meter) Dextre performed the most intricate task ever attempted by a space robot: cutting two separate "lock wires" 20 thousandths of an inch (0.5 millimeters) in diameter using the RRM Wire Cutter Tool (WCT). Deftly maneuvered by ground-based mission operators and Dextre, the WCT smoothly slid its hook under the individual wires and severed them with only a few millimeters of clearance. This wire-cutting activity is a prerequisite to removing and servicing various satellite parts during any future in-orbit missions.

    RRM operations are scheduled to resume in May 2012 with the completion of the gas fittings removal task. The RRM Refueling task is scheduled for later this summer. NASA and CSA will present RRM results at the Second International Workshop on on-Orbit Servicing, hosted by Goddard May 30-31, 2012.

    Dextre and RRM are an example of how robots are changing operations in space. Another is Robonaut 2, or R2, a project of NASA and General Motors. R2, the first human-like robot, was launched into space in 2011 and is a permanent resident of the International Space Station.

    For more information about RRM or the On-Orbit Servicing Workshop, visit:

    http://ssco.gsfc.nasa.gov
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  18. Top | #119
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          Pratt & Whitney Rocketdyne Hot-Fires Launch Abort Engine

    Image above: Pratt & Whitney Rocketdyne hot-fires a launch abort engine for Boeing, which is developing its CST-100 spacecraft for NASA's Commercial Crew Program.
    Image credit: Pratt & Whitney Rocketdyne
    › Larger image

    Image above: Pratt & Whitney Rocketdyne hot-fires a launch abort engine for Boeing, which is developing its CST-100 spacecraft for NASA's Commercial Crew Program.
    Image credit: Pratt & Whitney Rocketdyne
    › Larger image

    Image above: Pratt & Whitney Rocketdyne hot-fires a launch abort engine for Boeing, which is developing its CST-100 spacecraft for NASA's Commercial Crew Program.
    Image credit: Pratt & Whitney Rocketdyne
    › Larger image

    Pratt & Whitney Rocketdyne, which is supporting The Boeing Company during the development of its CST-100 spacecraft in NASA's Commercial Crew Development Round 2 (CCDev2), completed mission-duration hot-fire tests on a launch abort engine on Friday, March 9. The demonstration in Canoga Park, Calif., is one of many milestones Boeing is meeting for its funded Space Act Agreement during CCDev2.

    "Boeing and its contractor, Pratt & Whitney Rocketdyne, continue to make good progress on milestones supporting the development of their commercial crew transportation capabilities," said Ed Mango, Commercial Crew Program program manager. "The eventual availability of these capabilities from a U.S. domestic provider will enhance U.S. competitiveness and open new markets for the U.S. aerospace industry."

    Boeing's Crew Space Transportation system is a reusable, capsule-shaped spacecraft designed to take up to seven people, or a combination of people and cargo, to low Earth orbit, including the International Space Station. Its service module and integrated launch abort propulsion system are designed to push the crew capsule to safety if an abort becomes necessary during launch or ascent. If an abort is not necessary, the system's propellant could be used for other portions of a mission, including re-boosting the orbit of the space station.

    "We achieved full thrust on the 40,000-pound thrust-class engine while validating key operating conditions during engine start-up and shut down," said Terry Lorier, Pratt and Whitney Rocketdyne's Commercial Crew Development program manager, who supports Boeing's program.

    Under its fixed-price contract with Boeing, Pratt and Whitney Rocketdyne is combining its Attitude Control Propulsion System thrusters from heritage spaceflight programs, Bantam abort engine design and storable propellant engineering capabilities.

    "The tests provided key thermal and analytical data," Lorier said. "We are well on our way to providing an important propulsion system for safe, reliable human spaceflight."

    All of NASA's industry partners under CCDev2 continue to meet their established milestones in developing commercial crew transportation capabilities.

    For more information about NASA's Commercial Crew Program and CCDev2, visit:

    http://www.nasa.gov/commercialcrew
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  19. 4 کاربر مقابل از گلناز عزیز به خاطر این پست مفید تشکر کرده اند.


  20. Top | #120
    کاربر فعال

    عنوان کاربر
    کاربر فعال
    تاریخ عضویت
    Jun 2011
    شماره عضویت
    915
    نوشته ها
    139
    تشکر
    331
    تشکر شده 534 بار در 125 ارسال

          Big Sunspot Remains Active

    Astronomical News         
    On March 13, 2012, the sun erupted with an M7.9-class flare that peaked at 1:41 p.m. EDT. This flare was from the same active region, No. 1429, that has been producing flares and coronal mass ejections all week. That region has been moving across the face of the sun since March 2, and will soon rotate out of Earth view.


    NASA's Solar Dynamics Observatory (SDO) captured this image of an M7.9 class flare on March 13, 2012 at 1:29 p.m. EDT. It is shown here in the 131 Angstrom wavelength, a wavelength particularly good for seeing solar flares and a wavelength that is typically colorized in teal. (Image credit: NASA/SDO)
    › Larger image




    What is a solar flare? What is a coronal mass ejection?

    For answers to these and other space weather questions, please visit the Spaceweather Frequently Asked Questions page.
    امضای ایشان
    چند روزه نمی تونم برم تو خودم!
    فکر کنم از درون فیلتر شدم


  21. 6 کاربر مقابل از گلناز عزیز به خاطر این پست مفید تشکر کرده اند.


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