#magnetars

Neutron Star, Pulsar, Magnetar and Redbacks and Black Widows

When a star fuses matter it creates a outward pressure against the gravity that its mass causes, which tries to crush inwards. Eventually, the star will run out of matter it can fuse, and the star will begin to collapse inwards.

If the remaining core is less than 1.4 times the mass of our Sun, then a white dwarf will be born, a ball of mostly oxygen and carbon around the size of our planet.

If the star was massive, and there is more than 1.4 times the mass of the Sun left, then gravity can continue to crush down, crushing up atoms into a giant ball of neutrons. The limit between a white dwarf and a neutron star is known as the Chandrasekhar Limit.

Neutron stars despite being more massive, are much smaller, ranging from the size of the moon down to the size of a large city. Like white dwarfs, Neutron stars also have limits, one of the most massive found is J0740+6620, 2.17 times the mass of the Sun, squeezed into just 30km in diameter. 

Beyond that, Black Holes form ! 

So What’s a Pulsar ? 

When a neutron star is formed, it does so with a bit of a spin, while many spin within seconds, some extreme stars spin in the milliseconds. Emanating from it’s polar regions are vast jets of particles and sub atomic particles which act rather like a lighthouse. Every neutron star does this, but not all of them are aligned in such a way that we catch the beam. So, the ones we can see, we call Pulsars. 

What about Magnetars ?

Magnetars are just the extreme end of the Pulsars, those millisecond pulsars generate huge magnetic fields, and hence we call them Magnetars, but they are all neutron stars.

Now for the Spider Connection

These millisecond pulsars are often span up so much because when the neutron star was formed, it was part of a binary star system, and if those stars happen to be close enough, the neutron star can accrete a lot of material from the other star, causing massive supernova styled explosions and spinning up the neutron star, additionally, it can continue to feed it after its birth.

There are two types of systems, a neutron star that ended up with a low mass small red dwarf partner, which we call a black widow, and a neutron star that partners with a much larger mass star, which is the redback.

These are both rare and of great interest to astronomers, due to the fact neutron stars are generally not visible optically (due to their size) and only the pulses or the gravitational effects on partner stars is noticeable. So to have a confirmed pulsar (ie neutron star) with a star orbiting it can reveal a lot of information, otherwise impossible to obtain.

a sugar cube-sized piece of a neutron star weighs about the same as 100,000 fully loaded ocean freighters

something to ponder

(via The Most Powerful Magnetic Fields In The Universe Have Been Explained | IFLScience)

Magnetars or Neutron Stars are massive stars of degenerate matter. Probably they are the primordial stage of the Black Hole.

Only 10km in diameter with a weight of up to 3 solar masses. A teaspoon of matter would weigh billions of tons. They can rotate on themselves up to 43,000 times per minute with a million billion more powerful magnetic field than the Earth's.

There, we came right out and said it. They can’t help it; it’s just what happens when you have a star that’s heavier than our sun but as small as a city. Neutron stars give us access to crazy conditions that we can’t study directly on Earth.

Here are five facts about neutron stars that show sometimes they are stranger than science fiction!

1. Neutron stars start their lives with a bang

When a star bigger and more massive than our sun runs out of fuel at the end of its life, its core collapses while the outer layers are blown off in a supernova explosion. What is left behind depends on the mass of the original star. If it’s roughly 7 to 19 times the mass of our sun, we are left with a neutron star. If it started with more than 20 times the mass of our sun, it becomes a black hole.

2. Neutron stars contain the densest material that we can directly observe

While neutron stars’ dark cousins, black holes, might get all the attention, neutron stars are actually the densest material that we can directly observe. Black holes are hidden by their event horizon, so we can’t see what’s going on inside. However, neutron stars don’t have such shielding. To get an idea of how dense they are, one sugar cube of neutron star material would weigh about 1 trillion kilograms (or 1 billion tons) on Earth—about as much as a mountain. That is what happens when you cram a star with up to twice the mass of our sun into a sphere the diameter of a city.

3. Neutron stars can spin as fast as blender blades

Some neutron stars, called pulsars, emit streams of light that we see as flashes because the beams of light sweep in and out of our vision as the star rotates. The fastest known pulsar, named PSR J1748-2446ad, spins 43,000 times every minute. That’s twice as fast as the typical household blender! Over weeks, months or longer, pulsars pulse with more accuracy than an atomic clock, which excites astronomers about the possible applications of measuring the timing of these pulses.

4. Neutron stars are the strongest known magnets

Like many objects in space, including Earth, neutron stars have a magnetic field. While all known neutron stars have magnetic fields billions and trillions of times stronger than Earth’s, a type of neutron star known as a magnetar can have a magnetic field another thousand times stronger. These intense magnetic forces can cause starquakes on the surface of a magnetar, rupturing the star’s crust and producing brilliant flashes of gamma rays so powerful that they have been known to travel thousands of light-years across our Milky Way galaxy, causing measurable changes to Earth’s upper atmosphere.

5. Neutron stars’ pulses were originally thought to be possible alien signals

Beep. Beep. Beep. The discovery of pulsars began with a mystery in 1967 when astronomers picked up very regular radio flashes but couldn’t figure out what was causing them. The early researchers toyed briefly with the idea that it could be a signal from an alien civilization, an explanation that was discarded but lingered in their nickname for the original object—LGM-1, a nod to the “little green men” (it was later renamed PSR B1919+21). Of course, now scientists understand that pulsars are spinning neutron stars sending out light across a broad range of wavelengths that we detect as very regular pulses – but the first detections threw observers for a loop.

The Neutron star Interior Composition Explorer (NICER) payload that is soon heading to the International Space Station will give astronomers more insight into neutron stars—helping us determine what is under the surface. Also, onboard NICER, the Station Explorer for X-ray Timing and Navigation Technology (SEXTANT) experiment will test the use of pulsars as navigation beacons in space.

Want to learn even more about Neutron Stars? Watch this...