What the heck is a Magnestar?
This sounds like an Anime character. However, it's a type of star in space.
First of all we have to define what a neutron star is because a magnestar is a special type of neutron star. A neutron star is what's left over from a supernova, which is the violent death of a massive star. When a massive star explodes in a supernova it blasts a lot of its outer layers away to form a nebula, but the core of the massive star remains and collapses into a very dense ball around seven miles in diameter. This dense ball of star stuff has the mass of two of our suns condensed down into an object that has a diameter of around six to seven miles. This means that the stuff that a neutron star is made out of is three to four times the mass of our sin and up to ten to the fourteenth power denser than the stuff our sun is made out of. The gravitation of a neutron star is so strong a human would be crushed into monomolecular layer if said human came within a few miles of the star. Wow!
Think about it this way: an atom is made up of a very tiny nucleus surrounded by orbiting electrons. If you had a pea and held at the center of a football stadium, the orbiting electrons would be at the peripheral of the stadium. In other words atoms are mostly empty. Now, take away the electrons and shove nuclei of atoms together. Now, instead of nuclei, make them only neutrons, and you get an idea of how dense that would be.
What makes a magnestar so special is that it has an extremely powerful (ten to the eighth or tenth teslas) magnetic field and they emit strong X-rays and gamma rays. (The Earth's magnetic field is only 25 to 65 microtesla). These babies are bad boys. They are extremely dangerous, only being secondary to a black hole.
Magnestars are around 12 miles in diameter and are very dense. A few cubic centimeters of a magnestar would weigh at least a hundred million tons. A marble sized hunk of magnestar would fall all the way through the Earth like a hot knife through butter. However, no one is ever going to test this idea. If a human came within thousands of miles of a magnestar, the iron would be ripped out of his or her blood, and their credit cards would be wiped clean, but even before this happened they would die from overexposure to radiation.
One of the most interesting properties of a magnestars is that they rotate fast, often once every second to ten seconds. Typical neutron stars rotate faster, but the difference in the case of a magnestar is that they radiate powerful emissions of gamma and X-rays with each pulse.
The only good thing about a magnestar is that they don't live very long. Their magnetic field diminishes in ten thousand years and that leads to a drop off of radiation, and it's this radiation that characterizes a magnestar. Astronomers find them by looking for extra strong pulses of gamma and X-rays that are slower than pulsars (a different form of neutron star).
The emission of gamma rays from a magnestar would constitute a danger to astronauts out in space. One of the closest magnestars is only 6000 light years away. Most of them are much further away, mostly towards the center of the Milky Way galaxy where bad things happen. So, the moral to take from this is not to carry your credit cards while out in space.
Thanks for reading.