{
    "count": 8,
    "next": null,
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    "results": [
        {
            "id": 10767,
            "url": "https://svs.gsfc.nasa.gov/10767/",
            "result_type": "Produced Video",
            "release_date": "2011-05-11T12:00:00-04:00",
            "title": "NASA's Fermi Spots 'Superflares' in the Crab Nebula",
            "description": "The famous Crab Nebula supernova remnant has erupted in an enormous flare five times more powerful than any previously seen from the object. The outburst was first detected by NASA's Fermi Gamma-ray Space Telescope on April 12 and lasted six days.The nebula, which is the wreckage of an exploded star whose light reached Earth in 1054, is one of the most studied objects in the sky. At the heart of an expanding gas cloud lies what's left of the original star's core, a superdense neutron star that spins 30 times a second. With each rotation, the star swings intense beams of radiation toward Earth, creating the pulsed emission characteristic of spinning neutron stars (also known as pulsars). Apart from these pulses, astrophysicists regarded the Crab Nebula to be a virtually constant source of high-energy radiation. But in January, scientists associated with several orbiting observatories — including NASA's Fermi, Swift and Rossi X-ray Timing Explorer — reported long-term brightness changes at X-ray energies.Scientists think that the flares occur as the intense magnetic field near the pulsar undergoes sudden restructuring. Such changes can accelerate particles like electrons to velocities near the speed of light. As these high-speed electrons interact with the magnetic field, they emit gamma rays in a process known as synchrotron emission.To account for the observed emission, scientists say that the electrons must have energies 100 times greater than can be achieved in any particle accelerator on Earth. This makes them the highest-energy electrons known to be associated with any cosmic source.Based on the rise and fall of gamma rays during the April outbursts, scientists estimate that the size of the emitting region must be comparable in size to the solar system. If circular, the region must be smaller than roughly twice Pluto's average distance from the sun.For more Crab Nebula media go to #10708. || ",
            "hits": 121
        },
        {
            "id": 10708,
            "url": "https://svs.gsfc.nasa.gov/10708/",
            "result_type": "Produced Video",
            "release_date": "2011-01-12T12:00:00-05:00",
            "title": "A Flickering X-ray Candle",
            "description": "The Crab Nebula, created by a supernova seen nearly a thousand years ago, is one of the sky's most famous \"star wrecks.\" For decades, most astronomers have regarded it as the steadiest beacon at X-ray energies, but data from orbiting observatories show unexpected variations, showing astronomers their hard X-ray \"standard candle\" isn't as steady as they once thought. From 1999 to 2008, the Crab brightened and faded by as much as 3.5 percent a year, and since 2008, it has faded by 7 percent. The Gamma-ray Burst Monitor on NASA's Fermi satellite first detected the decline, and Fermi's Large Area Telescope also spotted two gamma-ray flares at even higher energies. Scientists think the X-rays reveal processes deep within the nebula, in a region powered by a rapidly spinning neutron star — the core of the star that blew up. But figuring out exactly where the Crab's X-rays are changing over the long term will require a new generation of X-ray telescopes. || ",
            "hits": 57
        },
        {
            "id": 10706,
            "url": "https://svs.gsfc.nasa.gov/10706/",
            "result_type": "Produced Video",
            "release_date": "2011-01-10T16:00:00-05:00",
            "title": "Terrestrial Gamma-ray Flashes Create Antimatter",
            "description": "NASA's Fermi Gamma-ray Space Telescope has detected beams of antimatter launched by thunderstorms. Acting like enormous particle accelerators, the storms can emit gamma-ray flashes, called TGFs, and high-energy electrons and positrons. Scientists now think that most TGFs produce particle beams and antimatter.For additional animations showing bremsstrahlung and pair production gamma ray reactions, go here.For more visualizations showing Fermi's TGF detections, go to#3747, #3748, and #3756.For animations of the Fermi spacecraft and matter/antimatter, go to#10707 and #10651. || ",
            "hits": 222
        },
        {
            "id": 10540,
            "url": "https://svs.gsfc.nasa.gov/10540/",
            "result_type": "Produced Video",
            "release_date": "2009-12-09T10:00:00-05:00",
            "title": "Brightest-ever Flare From Blazar 3C 454.3",
            "description": "The blazar 3C 454.3, which lies 7.2 billion light-years away in the constellation Pegasus, underwent a series of intense flares in the fall of 2009. By December, it had become the brightest persistent gamma-ray source in the sky — more than ten times brighter than it was in the summer. These all-sky images, which record the numbers of high-energy gamma-rays captured by Fermi's Large Area Telescope on Dec. 3 and Nov. 18, clearly show the change. Typically, the Vela pulsar, which lies only 1,000 light-years away, is the sky's brightest persistent source of gamma rays. Blazar 3C 454.3, which is millions of times farther away, rose to twice Vela's brightness. Astronomers suspect the activity is driven by some change within the galaxy's black-hole-powered particle jet, but they do not understand the details. || ",
            "hits": 85
        },
        {
            "id": 10489,
            "url": "https://svs.gsfc.nasa.gov/10489/",
            "result_type": "Produced Video",
            "release_date": "2009-10-28T01:45:00-04:00",
            "title": "Gamma-ray Burst Photon Delay as Expected by Quantum Gravity",
            "description": "In this illustration, one photon (purple) carries a million times the energy of another (yellow). Some theorists predict travel delays for higher-energy photons, which interact more strongly with the proposed frothy nature of space-time. Yet Fermi data on two photons from a gamma-ray burst fail to show this effect, eliminating some approaches to a new theory of gravity. || ",
            "hits": 194
        },
        {
            "id": 10505,
            "url": "https://svs.gsfc.nasa.gov/10505/",
            "result_type": "Produced Video",
            "release_date": "2009-10-28T01:45:00-04:00",
            "title": "Blazars at Galactic North Pole, Seen in Fermi's First Year of Observations",
            "description": "Fermi has detected more than 1,000 gamma-ray sources. Half are associated with active galaxies called blazars. This movie shows one year of blazar activity, starting on Aug. 4, 2008, around the galactic north pole. This region includes the constellations Ursa Major, Virgo, Leo, Boötes, and Coma Berenices. || ",
            "hits": 24
        },
        {
            "id": 10507,
            "url": "https://svs.gsfc.nasa.gov/10507/",
            "result_type": "Produced Video",
            "release_date": "2009-10-28T01:45:00-04:00",
            "title": "Gamma-Rays from High-Mass X-Ray Binaries",
            "description": "In its first year, NASA's Fermi Gamma-ray Space Telescope discovered GeV (billions of electron volts) intensity variations revealing orbital motion in high-mass X-ray binaries (HMXBs). These are systems where a compact companion, such as a neutron star or a black hole, rapidly orbits a hot, young, massive star. The first examples include LSI +61 303, which sports a 26-day orbital period, and LS 5039 (3.9 days). This animation shows such a system. When the compact object lies far from its host star, TeV (trillions of electron volts) gamma-rays (white) are seen by ground-based gamma-ray observatories. But, as the object plunges closer to the star, the TeV emission is quenched and GeV emission turns on. Interactions by accelerated particles from the compact source with gas encircling the star — or in some systems, the star's light itself — is thought to be responsible for this change. || ",
            "hits": 64
        },
        {
            "id": 10508,
            "url": "https://svs.gsfc.nasa.gov/10508/",
            "result_type": "Produced Video",
            "release_date": "2009-10-28T01:45:00-04:00",
            "title": "Fermi All-Sky First Year Progress",
            "description": "This view of the gamma-ray sky constructed from one year of Fermi LAT observations is the best view of the extreme universe to date. The map shows the rate at which the LAT detects gamma rays with energies above 300 million electron volts — about 120 million times the energy of visible light — from different sky directions. Brighter colors equal higher rates. || ",
            "hits": 47
        }
    ]
}