Pulsars Archives

July 13, 2024July 13, 2024 by Mark Thompson

A Close Pulsar Measures 11.4 km Across

Animation of the millisecond pulsar PSR J0437-4715. On the left as seen from Earth. On the right as seen from the star's equatorial plane. (c) NASA/Sharon Morsink/Devarshi Choudhury et al.

When massive stars detonate as supernovae, they leave often behind a pulsar. These fast rotating stellar corpses have fascinated scientists since their discovery in 1967. One nearby pulsar turns 174 times a second and now, its size has been precisely measured. An instrument on board the International Space Station was used to measure x-ray pulses from the star. A supercomputer was then used to analyse its properties and found it was 1.4 times the mass of the Sun and measured only 11.4 km across!

November 30, 2023November 30, 2023 by Evan Gough

Spider Pulsars are Tearing Apart Stars in the Omega Cluster

Omega Centauri is the brightest globular cluster in the night sky. It holds about 10 million stars and is the most massive globular cluster in the Milky Way. It's possible that globulars and nuclear star clusters are related in some way as a galaxy evolves. Image Credit: ESO.

Pulsars are extreme objects. They’re what’s left over when a massive star collapses on itself and explodes as a supernova. This creates a neutron star. Neutron stars spin, and some of them emit radiation. When they emit radiation from their poles that we can see, we call them pulsars.

October 9, 2023October 9, 2023 by Brian Koberlein

A Pulsar Suddenly Threw Out Radiation 200 Times More Energetic

An illustration of the Vela pulsar with particles accelerated and launched out at near light speed by its magnetic field. Credit: Science Communication Lab for DESY

Pulsars are known for their regularity and stability. These fast-rotating neutron stars emit radio waves with such consistent pulses that astronomers can use them as a kind of cosmic clock. But recently a pulsar emitted gamma rays with tremendous energy. The gamma rays were the most energetic photons ever observed, with energies of more than 20 teraelectronvolts, and astronomers are struggling to understand how that’s possible. The results were published in Nature Astronomy, which describes the burst of gamma rays emanating from the Vela Pulsar.

July 12, 2023June 13, 2023 by Paul M. Sutter

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.

July 1, 2023July 1, 2023 by Brian Koberlein

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.

June 15, 2023June 15, 2023 by Matt Williams

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*.

July 27, 2022July 27, 2022 by Carolyn Collins Petersen

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.

May 5, 2022May 5, 2022 by Carolyn Collins Petersen

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.

May 3, 2022May 3, 2022 by Carolyn Collins Petersen

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.

March 17, 2022March 17, 2022 by Evan Gough

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.