Magnetars

Although the Universe looks beautiful when we see through the telescope or even through naked eye, living here on Earth is Paradise… Trust me! Because it takes about 90 years for an average human being to lose life. But do you know what would kill you in a fraction of a fraction of a second? A Neutron Star. Nothing in this universe is more lethal than Supernova remnants which is a neutron star itself. One in ten neutron stars does something really strange, becoming one of the most terrifying and mysterious objects in the Universe. They are Magnetars.

Magnetars are the incredible stellar objects. The one thing we might have studied something that relates to Magnetars is the Magnetic field. It’s the magnetic field that makes it special.

Before knowing what magnetars actually are, lets get a recall about what is magnetic field (MF). (Disclaimer: If you are an expert, you can very well skip this paragraph. It contains basic level information about magnetic fields. If you are not, well, this is for you) Every object in this universe emits a magnetic field. For instance, even you emit a magnetic field. The human body is a good conductor of electricity. Each organ and cell in the human body has its own field that are keeping you together. And what about stars and planets? Yes, they do emit magnetic fields. We very well know that the Earth’s magnetic field (a layer called magnetosphere) protects us from the Solar winds. How a magnetic field usually caused at the Earth’s atmosphere is that when the currents of electricity that are hundreds of miles wide and flows in the molten core at thousands of miles per hour as the Earth rotates, the powerful magnetic field passes out through the core of the Earth, it passes through the crust and enters space. That’s how a MF is formed in any stellar object. Ironically, not every planet in our Solar system has a magnetic field. The Voyager probe measured that Jupiter having the largest MF, followed by Saturn, Uranus and Neptune has magnetic fields much stronger than that of the Earth. Whereas, Mercury was thought to be cold and dead inside, thus having no MF. Also, the probe found that Mars and Venus do not have a significant MF. Do magnetic fields affect the human body? MF’s are harmful when their strength is above 3000 Gauss. As we are evolved with the Earth’s magnetic field (0.6 Gauss), being on Earth would not affect us. But to people who do space exploration, magnetic storms can cause bad health, not due to the magnetic field itself, but due to the exposure of its radiation

Let’s fall back to our topic, Magnetars. They are the type of Neutron Star (a dense star that resulted from the supernovae of massive stars). Neuron stars that have a strong magnetic field tend to emit electromagnetic radiation from their poles. These are called pulsars. Only a few pulsars develop an intense magnetic field resulting as ‘The Strongest magnets’ – “The Magnetars”. Knowing the strength of the magnetar would totally blow your mind. Let’s make a comparison, the Earth’s core has a magnetic field of about 25 gauss. And the surface, we experience 0.6 gauss. A bar magnet has about 100 gauss. The magnetic field of a regular neutron star is trillion gauss. Whereas, Magnetars are 1,000 times stronger. Quadrillion gauss is the magnetic field of the Magnetar. In fact, astronomers aren’t really sure what makes them so strong!

If the Magnetar’s magnetic field is 1000 times stronger than our Sun’s, it has to be very dense too. But, is it denser than the black hole? Even though magnetars are incredibly powerful, they would still be an epic fail when it battles with the Black Hole. Depending on the size and mass of both the black hole and the magnetar, the magnetar would be eaten up neither whole nor slowly, piece by piece by the black hole. As it was being eaten up, it would be passing gravitational waves throughout the Universe, causing disturbance in the curvature of space-time. Once the magnetar is completely consumed the black hole, its mass obviously would increase and expand its event horizon. More expansion is equal to more engulfing of stars and eating our galaxy. Black hole would have a feast. But thank the universe that no such event has occurred until now.

One of the interesting things about magnetars is that they can have Starquakes. You might have heard about the Earthquakes, but when it happens on stars…. Starquakes. When the neutron star is formed with the crust on the outside and degenerate matter inside, the crust of neutrons can crack, like the tectonic plates on Earth. This releases a blast of radiation which can be encountered throughout the galaxy. The most powerful starquake ever recorded came from a magnetar called SGR 1806-20 located approximately 50,000 light years away. Within a tenth of a second, this starquake released more energy than the Sun would produce in 100,000 years. And this is just due to a crack on the magnetar’s surface. The nearest known magnetar to Earth is 1E 1048.1-5937 and is located 9000 light years away from Earth in the constellation Carnia.

Fortunately, they are far away from us and there isn’t a necessity to worry about them getting close.