Neutron Stars Archives

September 17, 2019September 17, 2019 by Evan Gough

The Most Massive Neutron Star has been Found. It’s ALMOST the Most Massive Neutron Star That’s Even Possible

Artist's illustration of a rotating neutron star, the remnants of a super nova explosion. Credit: NASA, Caltech-JPL

Neutron stars are the end-state of massive stars that have spent their fuel and exploded as supernovae. There’s an upper limit to their mass, because a massive enough star won’t become a neutron star; it’ll become a black hole. But finding that upper mass limit, or tipping point, between a star that becomes a black hole and one that becomes a neutron star, is something astronomers are still working on.

Now a new discovery from astronomers using the National Science Foundation’s (NSF) Green Bank Telescope (GBT) have found the most massive neutron star yet, putting some solid data in place about the so-called tipping point.

September 11, 2019September 11, 2019 by Evan Gough

Hubble Has Looked at the 2017 Kilonova Explosion Almost a Dozen Times, Watching it Slowly Fade Away

An artistic rendering of two neutron stars merging. Credit: NSF/LIGO/Sonoma State/A. Simonnet

In 2017, LIGO (Laser-Interferometer Gravitational Wave Observatory) and Virgo detected gravitational waves coming from the merger of two neutron stars. They named that signal GW170817. Two seconds after detecting it, NASA’s Fermi satellite detected a gamma ray burst (GRB) that was named GRB170817A. Within minutes, telescopes and observatories around the world honed in on the event.

The Hubble Space Telescope played a role in this historic detection of two neutron stars merging. Starting in December 2017, Hubble detected the visible light from this merger, and in the next year and a half it turned its powerful mirror on the same location over 10 times. The result?

The deepest image of the afterglow of this event, and one chock-full of scientific detail.

August 14, 2019August 14, 2019 by Evan Gough

Neutron Star Suffers a “Glitch”, Gives Astronomers a Glimpse Into How They Work

An image of the Vela pulsar in combined optical and xray. Image Credit: NASA/Chandra

What, exactly, is the inside of a neutron star like?

A neutron star is what remains after a massive star goes supernova. It’s a tightly-packed, ultra-dense body made of—you guessed it—neutrons. Actually, that’s not absolutely true.

June 3, 2019June 3, 2019 by Matt Williams

NASA is building up a map of the entire sky seen in X-rays, line by line with its NICER experiment

X-ray data recorded by NASA's NICER instrument aboard the ISS. Credits: NASA/NICER

In June of 2017, NASA’s Neutron Star Interior Composition Explorer (NICER) was installed aboard the International Space Station (ISS). The purpose of this instrument is to provide high-precision measurements of neutron stars and other super-dense objects that are on the verge of collapsing into black holes. NICER is also be the first instrument designed to test technology that will use pulsars as navigation beacons.

Recently, NASA used data obtained from NICER’s first 22 months of science operations to create an x-ray map of the entire sky. What resulted was a lovely image that looks like a long-exposure image of fire dancers, solar flare activity from hundreds of stars, or even a visualization of the world wide web. But in fact, each bright spot represents an x-ray source while the bright filaments are their paths across the night sky.

May 29, 2019May 29, 2019 by Evan Gough

Astronomers are Finding Binary Pairs of Stars Thrown out of Galaxies Together

Two of the largest galaxies in the Fornax galaxy cluster. Image Credit: NASA/Chandra

A rogue star is one that has escaped the gravitational pull of its home galaxy. These stars drift through intergalactic space, and so are sometimes called intergalactic stars. Sometimes, when a rogue star is ejected from its galaxy, it drags its binary pair along for the ride.

May 7, 2019May 7, 2019 by Matt Williams

Some of Earth’s Gold Came From Two Neutron Stars That Collided Billions of Years Ago

Collisions of neutron stars produce powerful gamma-ray bursts – and heavy elements like gold (Credit: Dana Berry, SkyWorks Digital, Inc.)

For about a century now, scientists have theorized that the metals in our Universe are the result of stellar nucleosynthesis. This theory states that after the first stars formed, heat and pressure in their interiors led to the creation of heavier elements like silicon and iron. These elements not only enriched future generations of stars (“metallicity”), but also provided the material from which the planets formed.

More recent work has suggested that some of the heaviest elements could actually be the result of binary stars merging. In fact, a recent study by two astrophysicists found that a collision which took place between two neutron stars billions of years ago produced a considerable amount of some of Earth’s heaviest elements. These include gold, platinum and uranium, which then became part of the material from which Earth formed.

May 2, 2019May 5, 2019 by Evan Gough

It Looks Like LIGO/Virgo Have Detected a Black Hole Eating a Neutron Star. For the First Time Ever

A new signal detected by LIGO/Virgo may be the so-called ‘holy grail’ of astrophysics: the merger of a neutron star and a black hole. They’ve discovered pairs of black holes merging, and pairs of neutron stars merging, but until now, not a neutron star-black hole pair.

April 24, 2019April 24, 2019 by Paul M. Sutter

Barfing Neutron Stars Reveal Their Inner Guts

Artist's illustration of two merging neutron stars. The narrow beams represent the gamma-ray burst while the rippling spacetime grid indicates the isotropic gravitational waves that characterize the merger. Swirling clouds of material ejected from the merging stars are a possible source of the light that was seen at lower energies. Credit: National Science Foundation/LIGO/Sonoma State University/A. Simonnet

We don’t really understand neutron stars. Oh, we know that they are – they’re the leftover remnants of some of the most massive stars in the universe – but revealing their inner workings is a little bit tricky, because the physics keeping them alive is only poorly understood.

But every once in a while two neutron stars smash together, and when they do they tend to blow up, spewing their quantum guts all over space. Depending on the internal structure and composition of the neutron stars, the “ejecta” (the polite scientific term for astronomical projectile vomit) will look different to us Earth-bound observers, giving us a gross but potentially powerful way to understand these exotic creatures.

January 14, 2019January 14, 2019 by Evan Gough

Astronomers See the Exact Moment a Supernova Turned into a Black Hole (or Neutron Star)

A look at The Cow (approximately 80 days after explosion) from the W.M. Keck Observatory in Maunakea, Hawaii. The Cow is nestled in the CGCG 137-068 galaxy, 200 million light years from Earth. Image Credit:Raffaella Margutti/Northwestern University

On June 17th 2018, the ATLAS (Asteroid Terrestrial-impact Last Alert System) survey’s twin telescopes spotted something extraordinarily bright in the sky. The source was 200 million light years away in the constellation Hercules. The object was given the name AT2018cow or “The Cow.” The Cow flared up quickly, and then just as quickly it was gone.

What was it?

October 18, 2018 by Matt Williams

A Star Exploded as a Supernova and Then Collapsed Into a Neutron Star. But Only a Fraction of its Matter was Released

Artist's impression of a pulsar siphoning material from a companion star. Credit: NASA

For almost a century, astronomers have been studying supernovae with great interest. These miraculous events are what take place when a star enters the final phase of its lifespan and collapses, or is stripped by a companion star of its outer layers to the point where it undergoes core collapse. In both cases, this event usually leads to a massive release of material a few times the mass of our Sun.

However, an international team of scientists recently witnessed a supernova that was a surprisingly faint and brief. Their observations indicate that the supernova was caused by an unseen companion, likely a neutron star that stripped its companion of material, causing it to collapse and go supernova. This is therefore the first time that scientists have witnessed the birth of a compact neutron star binary system.

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