Magnetar Glitches, Fast Radio Bursts, And…Asteroids???

A massive flare ejected from a magnetar.

Recently astronomers have been able to associate two seemingly unrelated phenomena: an explosive event known as a fast radio burst and the change in speed of a spinning magnetar. And now new research suggests that the cause of both of these is the destruction of an asteroid by a magnetar.

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Astronomers Find the Fastest Spider Pulsar, Filling in the Missing Link in Their Evolution

An illustration of FAST and a binary pulsar. Credit:ScienceApe/CAS/NAOC

Pulsars are rotating neutron stars aligned with Earth in just such a way that the energy radiated from their magnetic poles sweeps across us with each rotation. From this, we see a regular pulse of radio light, like a cosmic lighthouse. The fastest pulsars can rotate very quickly, pulsing hundreds of times per second. These are known as millisecond pulsars.

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Pulsars Could Help Map the Black Hole at the Center of the Milky Way

The Atacama Large Millimeter/submillimeter Array (ALMA) looked at Sagittarius A*, (image of Sag A* by the EHT Collaboration) to study something bright in the region around Sag A*. Credit: ESO/José Francisco Salgado.

The Theory of General Relativity (GR), proposed by Einstein over a century ago, remains one of the most well-known scientific postulates of all time. This theory, which explains how spacetime curvature is altered in the presence of massive objects, remains the cornerstone of our most widely-accepted cosmological models. This should come as no surprise since GR has been verified nine ways from Sunday and under the most extreme conditions imaginable. In particular, scientists have mounted several observation campaigns to test GR using Sagittarius A* (Sgr A*), the supermassive black hole at the center of the Milky Way.

Last year, the Event Horizon Telescope (EHT) – an international consortium of astronomers and observatories – announced they had taken the first images of Sag A*, which came just two years after the release of the first-ever images of an SMBH (M87). In 2014, the European members of the EHT launched another initiative known as BlackHoleCam to gain a better understanding of SMBHs using a combination of radio imaging, pulsar observations, astrometry, and GR. In a recent paper, the BHC initiative described how they tested GR by observing pulsars orbiting Sgr A*.

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The Heaviest Neutron Star Ever Seen Got There by Feasting on its Companion

Life’s not too good if you’re the companion of a black widow. Here on Earth, spiders by that name feast on their smaller significant others after mating. Out in space, some weird objects do the same thing to their closeby neighbors. They’re rapidly spinning neutron stars that slowly destroy their companion stars with powerful outflows of high-energy particles. A team at the University of California Berkeley is studying one of these so-called “black widow pulsars”, called PSR J0952-0607. Thanks to its hefty appetite, it shredded and consumed nearly all of its stellar companion. That eating spree made it the heaviest known neutron star to date.

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A Pulsar and Star are Orbiting Each Other Every 62 Minutes. The Fastest “Black Widow” Binary Ever Seen

Caption:An illustrated view of a black widow pulsar and its stellar companion. The pulsar’s gamma-ray emissions (magenta) strongly heat the facing side of the star (orange). The pulsar is gradually evaporating its partner.
Credits:Credit: NASA's Goddard Space Flight Center/Cruz deWilde
Caption: An illustrated view of a black widow pulsar and its stellar companion. The pulsar’s gamma-ray emissions (magenta) strongly heat the facing side of the star (orange). The pulsar is gradually evaporating its partner. Courtesy NASA’s Goddard Space Flight Center/Cruz deWilde

The Milky Way Galaxy has its share of oddities, from black holes and magnetars to luminous blue variable stars and strange new worlds. But, have you ever heard of a “black widow binary?” Not exactly an easy name to wrap your head around, especially if you’re afraid of spiders. But, these things actually exist in our galaxy and they’re fascinating.

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Pulsars Could Explain the Excess of Gamma Radiation Coming from the Center of the Milky Way

A gamma-ray view of the sky centered on the core of the Milky Way Galaxy. Could strange spinning neutron stars explain an excess of gamma-radiation emanating from the Milky Way's core region? That's one possibility astronomers are discussing. Courtesy NASA/DOE/Fermi LAT Collaboration
A gamma-ray view of the sky centered on the core of the Milky Way Galaxy. Could strange spinning neutron stars explain a mysterious excess of gamma radiation emanating from the core region? That’s one possibility astronomers are discussing. Courtesy NASA/DOE/Fermi LAT Collaboration

Ever hear of the Galactic Center GeV Excess? No, it’s not a cosmic rock band, although that’s a great name for one. Actually, it’s what astronomers call a super-high rate of gamma-ray radiation coming from the heart of our Milky Way Galaxy. Since this Galactic Center Excess was first detected in 2009, people thought it might be a signature of dark matter annihilating itself in mass quantities. But, as with any unexplained phenomenon in space, others disagreed. It could also have something to do with Sagittarius A*, the galaxy core’s own supermassive black hole. Or, it might be some other kind of strange burst event. Now, an astronomer at the Australian National University suggests that rapidly spinning neutron stars may be the culprits behind this high-energy galactic mystery.

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A Pulsar is Blasting out Jets of Matter and Antimatter

This image from NASA's Chandra X-ray Observatory and ground-based optical telescopes shows an extremely long beam, or filament, of matter and antimatter extending from a relatively tiny pulsar, as reported in our latest press release. With its tremendous scale, this beam may help explain the surprisingly large numbers of positrons, the antimatter counterparts to electrons, scientists have detected throughout the Milky Way galaxy. Image Credit: X-ray: NASA/CXC/Stanford Univ./M. de Vries; Optical: NSF/AURA/Gemini Consortium

Why is there so much antimatter in the Universe? Ordinary matter is far more plentiful than antimatter, but scientists keep detecting more and more antimatter in the form of positrons. More positrons reach Earth than standard models predict. Where do they come from?

Scientists think pulsars are one source, and a new study strengthens that idea.

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Astronomers Scan 800 Pulsars to See If Any of Them Have Planets

Lich (PSR B1257+12) is a pulsar 2,300 ly away in the constellation of Virgo - 20 km in diameter, formed 2 billion years ago by two white dwarfs merging with each other - Has three known planets, named Draugr, Poltergeist and Phobetor - Both the first extrasolar planets and the first pulsar planets to be discovered - Draugr is the lowest-mass planet yet discovered by any observational technique (twice the mass of Earth's moon.) Image Credit: By Pablo Carlos Budassi - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=94333766

Astronomers discovered the first exoplanets in 1992. They found a pair of them orbiting the pulsar PSR B1257+12 about 2300 light-years from the Sun. Two years later they discovered the third planet in the system.

Now a team of astronomers are trying to duplicate that feat by searching 800 known pulsars for exoplanets.

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Twin Stars Prove Einstein at Least 99.99% Right

Artistic impression of the Double Pulsar system, where two active pulsars orbit each other in just 147 min. The orbital motion of these extremely dense neutrons star causes a number of relativistic effects, including the creation of ripples in spacetime known as gravitational waves. The gravitational waves carry away energy from the systems which shrinks by about 7mm per days as a result. The corresponding measurement agrees with the prediction of general relativity within 0.013%. The picture at high resolution and two alternative versions (1b, 1c) are accessible in the left column. [less] © Michael Kramer/MPIfR

More than a hundred years have passed since Einstein formalized his theory of General Relativity (GR), the geometric theory of gravitation that revolutionized our understanding of the Universe. And yet, astronomers are still subjecting it to rigorous tests, hoping to find deviations from this established theory. The reason is simple: any indication of physics beyond GR would open new windows onto the Universe and help resolve some of the deepest mysteries about the cosmos.

One of the most rigorous tests ever was recently conducted by an international team of astronomers led by Michael Kramer of the Max Planck Institute for Radio Astronomy (MPIfR) in Bonn, Germany. Using seven radio telescopes from across the world, Kramer and his colleagues observed a unique pair of pulsars for 16 years. In the process, they observed effects predicted by GR for the first time, and with an accuracy of at least 99.99%!

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Astronomers can use Pulsars to Measure Tiny Changes of Acceleration Within the Milky Way, Scanning Internally for Dark Matter and Dark Energy

Using pulsars to measure mass distribution in the Milky Way. Credit: Dana Berry, IAS

As our Sun moves along its orbit in the Milky Way, it is gravitationally tugged by nearby stars, nebulae, and other masses. Our galaxy is not a uniform distribution of mass, and our Sun experiences small accelerations in addition to its overall orbital motion. Measuring those small tugs has been nearly impossible, but a new study shows how it can be done.

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