- 2999 - NEUTRON STARS - and magnetars? - Astronomers may have captured the first good look at giant flares from the strongest magnets in the universe. The likely cause of these giant flares that are Starquakes trillions of trillions of times stronger than any earthquakes.
---------------------- 2999 - NEUTRON STARS - and magnetars?
- The most powerful magnets in the cosmos are “magnetars“, which possess magnetic fields about 100 trillion times more powerful than Earth's, or 10 trillion times that of an ordinary fridge magnet.
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- Magnetars are a rapidly spinning kind of “neutron star“, which is a corpse of a star that died in a catastrophic explosion known as a supernova. Magnetars are up to a thousand times more magnetic than ordinary neutron stars.
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- In the Milky Way there are tens of thousands of neutron stars. Of those, only 30 are currently known to be magnetars. Once magnetars are born, they only stay magnetars for about 10,000 years before their magnetic fields weaken to render them relatively ordinary neutron stars
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- Magnetars are typically seen in star-forming regions, such as starburst galaxies. Previous research discovered magnetars regularly explode with X-ray bursts about one-tenth of a second long that each pack up to about the same amount of energy the sun gives off in a year.
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- In three instances over the past 40 years, astronomers have seen magnetars in the Milky Way and nearby galaxies explode with even brighter, more energetic outbursts of X-rays and gamma rays.
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- Scientists analyzed the extremely bright gamma-ray burst “GRB 200415A“, which five space observatories detected on April 15, 2020. Gamma-ray bursts are the most powerful kinds of explosions known in the universe, each giving off as much energy in milliseconds to minutes as the Sun is expected to emit during its entire 10-billion-year lifetime.
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- The three nearest magnetar giant flares ever detected erupted in 1979 in the Large Magellanic Cloud; the others erupted in 1998 and 2004 within our galaxy. At its peak, this newfound explosion was about 360 trillion times more luminous than the sun. That is about 100,000 years of solar energy released in only 140 milliseconds.
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- The location of the gamma-ray burst was the center of the nearby Sculptor galaxy, formally known as NGC 253, which is located about 11.4 million light-years from Earth in the Sculptor constellation.
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- Previously detected GRBs came from relatively far away from the Milky Way, but GRB 200415A originated much closer to home, in cosmic terms.
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- Gamma-ray bursts are typically divided into two groups, long and short, depending on whether they last more or less than two seconds. Short gamma-ray bursts are most likely caused by the mergers of neutron stars, while long gamma ray-bursts are linked with supernovas.
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- “GRB 200415A” lasted just 140 milliseconds, about the blink of an eye. This speed would ordinarily suggest it was a short gamma-ray burst. However, the pattern of light seen from this outburst was very different from that seen from short gamma-ray bursts that previous research found were caused by colliding neutron stars.
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- Instead, GRB 200415A's light pattern was a near copy of those previously seen from giant magnetar flashes. Those began with an intense flash about one-fifth of a second long, followed by a string of pulses lasting about two to 12 seconds.
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- The cause of this giant magnetar flare was likely a "starquake", a rupture of the magnetar's solid crust. This quake was huge, magnitude 27.8 in strength, or about one thousand trillion trillion (10^27, or a 1 with 27 zeroes) times more powerful than the largest known terrestrial earthquake, which was the magnitude 9.5 earthquake in Chile in 1960.
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- This starquake not only released a bright flash of gamma rays, it also heated the magnetar's crust. As the magnetar whirls around, this super-hot crust looks like a series of bright flashes that dim as the surface cools.
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- This starquake likely also sent out a blob of plasma traveling about 99% the speed of light. After four days, this blob encountered the shockwave created when the giant bubble of plasma around the magnetar, known as its magnetosphere, slammed into the interstellar medium of gas and dust between stars at a speed of about 2.2 million mph.
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- When the blob collided with this shockwave, it generated another pulse of gamma rays seen 19 seconds after the initial flash. The gamma rays in this second outburst were even more energetic than those seen in the first one.
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- Astronomers are winding back the clock on the expanding remains of a nearby, exploded star. They have retraced the speedy shrapnel from the blast to calculate a more accurate estimate of the location and time of the stellar detonation.
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- The victim is a star that exploded long ago in the Small Magellanic Cloud, a satellite galaxy to our Milky Way. The doomed star left behind an expanding, gaseous corpse, a supernova remnant named 1E 0102.2-7219.
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- Like detectives, researchers sifted through archival images taken by Hubble, analyzing visible-light observations made 10 years apart. The research team measured the velocities of 45 tadpole-shaped, oxygen-rich clumps of ejecta flung by the supernova blast. Ionized oxygen is an excellent tracer because it glows brightest in visible light.
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- To calculate an accurate explosion age, the astronomers picked the 22 fastest moving ejecta clumps, or knots. The researchers determined that these targets were the least likely to have been slowed down by passage through interstellar material.
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- They then traced the knots' motion backward until the ejecta coalesced at one point, identifying the explosion site. Once that was known, they could calculate how long it took the speedy knots to travel from the explosion center to their current location.
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- The light from the blast arrived at Earth 1,700 years ago, during the decline of the Roman Empire. However, the supernova would only have been visible to inhabitants of Earth's southern hemisphere. Unfortunately, there are no known records of this titanic event.
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- Hubble clocked the speed of a suspected neutron star, the crushed core of the doomed star, that was ejected from the blast. The neutron star must be moving at more than 2 million miles per hour from the center of the explosion to have arrived at its current position.
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- That is at the extreme end of how fast we think a neutron star can be moving, even if it got a kick from the supernova explosion. So the hunt may still be on for the neutron star. This study doesn't solve the mystery, but it gives an estimate of the velocity for the candidate neutron star. Let us know if you find it.
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---------------------------------- Other reviews available:
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- 2994 - NEUTRON STAR - amazing math and physics? -Neutron Stars are amazing objects for astronomers to study. The Crab Nebula is powered by a neutron star. Ordinary Matter should be called Ordinary Space. The matter part is almost negligible. 99.999,999,999,999,9 % of solid matter is empty space. It is not solid at all. What makes it feel solid is the electromagnetic force.
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- 2960 - NEUTRON STARS - to measure expansion of the universe. How fast is the Universe expanding? Ever since the expanding Universe was first discovered nearly 100 years ago, it’s been one of the biggest questions plaguing cosmology. If you can measure how fast the Universe is expanding right now, as well as how the expansion rate is changing over time, you can figure out everything you’d want to know about the Universe as a whole.
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- 2950 - NEUTRON STARS - it dosn’t get any stranger? Astronomy has many, many strange things to try to figure out. Let’s start with “neutron stars“. The crushing gravity, intense magnetic fields, and lightning-fast rotations place “neutron stars” among the most exotic beasts in the universe. Next come the most powerful magnetic fields in the universe wrack the searing surfaces of neutron stars called “magnetars“. These magnetic monsters form one of the most eccentric branches on the neutron star-pulsar family tree.
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- 1897 - The mysterious Neutron Stars, Pulsars, and Quasars create radio bursts of energy that astronomers are still trying to explain. There are mysterious radio bursts coming to us from far away galaxies. Since 2007 some 20 pulses have been recorded. The pulses only last for a few milliseconds, but, they release the energy equal to a million suns.
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- 1327 - Neutron Stars - The surface is solid and harder that a diamond, 50 trillion times denser than solid lead. Its magnetic field is a trillion times more intense than that of our Sun.
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- 1273 - Neutron Star - Are Astronomical Mergers in our Future? Mergers are going on all the time in our Universe. Some are large, some are relatively small. Our galaxy is relatively quiet right now. We should use this time to study what might happen when these mergers do occur?
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- 1192 - The new zoo of Pulsars. When a star runs out of fuel it dies. When our star dies, the one we call our Sun, it will become a White Dwarf. When the central 10% of our Sun has no more hydrogen for fusion the core will shrink and the hydrogen fusion will move from the center to a shell surrounding a core of helium. This will happen about 5,000,000,000 years from now. When it happens the Sun will expand to many times its present size. The Sun will continue to get its energy from hydrogen fusion into helium until about 50% of the total mass is helium. Then, quite suddenly, it will switch to fusing helium into carbon and oxygen.
- 861 - Cannon Ball Star. Astronomers have discovered a Neutron Star shooting across the Milky Way Galaxy at 3,000,000 miles per hour. The star is traveling so fast it exceeds the escape velocity for the galaxy and will launch itself into intergalactic space. Astronomers are trying to find the cannon that could shoot this star into space with so much energy.
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- 642 - Neutron Stars, Pulsars, and Magnetars.
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- January 24, 2021 NEUTRON STARS - and magnetars 2999
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