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.
Continue reading “Neutron Star Suffers a “Glitch”, Gives Astronomers a Glimpse Into How They Work”
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.
Continue reading “NASA is building up a map of the entire sky seen in X-rays, line by line with its NICER experiment”
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.
Continue reading “Astronomers are Finding Binary Pairs of Stars Thrown out of Galaxies Together”
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.
Continue reading “Some of Earth’s Gold Came From Two Neutron Stars That Collided Billions of Years Ago”
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.
Continue reading “It Looks Like LIGO/Virgo Have Detected a Black Hole Eating a Neutron Star. For the First Time Ever”
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.
Continue reading “Barfing Neutron Stars Reveal Their Inner Guts”
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?
Continue reading “Astronomers See the Exact Moment a Supernova Turned into a Black Hole (or Neutron Star)”
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.
Continue reading “A Star Exploded as a Supernova and Then Collapsed Into a Neutron Star. But Only a Fraction of its Matter was Released”
Ever since they were first discovered in the 1930s, scientists have puzzled over the mystery that is neutron stars. These stars, which are the result of a supernova explosion, are the smallest and densest stars in the Universe. While they typically have a radius of about 10 km (6.2 mi) – about 1.437 x 10-5 times that of the Sun – they also average between 1.4 and 2.16 Solar masses.
At this density, which is the same as that of atomic nuclei, a single teaspoon of neutron star material would weigh about as much as 90 million metric tons (100 million US tons). And now, a team of scientists has conducted a study that indicates that the strongest known material in the Universe – what they refer to as “nuclear pasta” – exists deep inside the crust of neutron stars.
Continue reading “Inside the Crust of Neutron Stars, There’s Nuclear Pasta; the Hardest Known Substance in the Universe”
In August of 2017, astronomers made another major breakthrough when the Laser Interferometer Gravitational-Wave Observatory (LIGO) detected gravitational waves that were believed to be caused by the merger of two neutron stars. Since that time, scientists at multiple facilities around the world have conducted follow-up observations to determine the aftermath this merger, as even to test various cosmological theories.
For instance, in the past, some scientists have suggested that the inconsistencies between Einstein’s Theory of General Relativity and the nature of the Universe over large-scales could be explained by the presence of extra dimensions. However, according to a new study by a team of American astrophysicists, last year’s kilonova event effectively rules out this hypothesis.
Continue reading “Last Year’s Gravitational Wave Detections Failed to Provide a Hint of Any Extra Spatial Dimensions”