Neutron stars

About Neutron Stars:

• Neutron stars are extremely dense and compact celestial objects formed when a massive star runs out of fuel and collapses.
• The very central region of the star, ‘the core’, collapses, crushing together every proton and electron into a neutron.
• If the core of the collapsing star is between about 1 and 3 solar masses, these newly-created neutrons can stop the collapse, leaving behind a neutron star. (Stars with higher masses will continue to collapse into stellar-mass black holes).
• Since neutron stars began their existence as stars, they are scattered throughout the galaxy in the same places where we find stars. And like stars, they can be found by themselves or in binary systems with a companion.
• Neutron stars are typically about 20 km (12 miles) in diameter.
• Their masses range between 1.18 and 1.97 times that of the Sun, but most are 1.35 times that of the Sun.
• Many neutron stars are likely undetectable because they simply do not emit enough radiation.
• Most neutron stars are observed as pulsars.
  • Pulsars are rotating neutron stars observed to have pulses of radiation at very regular intervals that typically range from milliseconds to seconds.
  • Pulsars have very strong magnetic fields, which funnel jets of particles out along the two magnetic poles. 
  • These accelerated particles produce very powerful beams of light.
• Neutron stars are also seen as objects called rotating radio transients (RRATs) and as magnetars.
  • The RRATs are sources that emit single radio bursts but at irregular intervals ranging from four minutes to three hours. The cause of the RRAT phenomenon is unknown.
  • Magnetars are neutron stars having an ultrahigh magnetic field that is much stronger than the terrestrial magnetic field. 

Q1: What is a Black hole?

A black hole is a region in space where gravity pulls so much that even light can not get out. The gravity is so strong because matter has been squeezed into a tiny space. This can happen when a star is dying. Because no light can get out, it is difficult to detect a black hole. The largest black holes are called "supermassive." These black holes have masses that are more than 1 million suns together. Albert Einstein first predicted the existence of black holes in 1916, with his general theory of relativity.

Source: 10 new dead star 'monsters' discovered at the heart of the Milky Way