What is a Neutron Star, Anyway?

Neutron stars are strange cosmic beasts. Stellar corpses that are several times the mass of our Sun but only about the width of Manhattan, they can contain a mountain’s worth of star-stuff within the space of a sugar cube, creating all sorts of weird physics that requires funny-sounding names like “quark-gluon plasma” to even try to describe what’s going on. The video above, created by Munich-based design studio Kurzgesagt (which means “in a nutshell” in German) illustrates how neutron stars form and what we think is happening on, around, and inside them.

See more In a Nutshell videos by Kurzgesagt on YouTube here, and find some interesting neutron star facts below:

Image of the neutron star inside the Crab Nebula, acquired by NASA's Chandra X-ray Observatory. Click for more info.
Image of the neutron star inside the Crab Nebula, acquired by NASA’s Chandra X-ray Observatory. Click for more info. (Credit: NASA/CXC/ASU/J.Hester et al.)

• Atomic nuclei are 99.9999999999999% empty space, but inside a neutron star all that space is taken up by neutrons and mashed-together protons and electrons.

• The gravity on the surface of a neutron star would be two hundred billion times more than on Earth, and the escape velocity needed to leave it would be half the speed of light!

• Neutron stars, although extremely hot, are nearly invisible in optical wavelengths. Most of their radiation is emitted in x-ray and radio.

• The magnetic field of a neutron star is more than a trillion times that of Earth’s – so strong that atoms within it get squeezed into cigar shapes!

• If you dropped 1kg of matter onto a neutron star (not advised) the energy released would be equal to a five megaton hydrogen bomb!

• Neutron stars can only be 1.4–3 times the mass of the Sun. Any more than that and they’d become black holes.

Black Holes and Neutron Stars by Cole Miller
Dave Goldberg, Ask a Physicist on io9.com
Chandra X-ray Observatory
KIPAC (Kavli Institute)


  1. Thanks for those links.

    Liked by 1 person

  2. Lauri says:

    Wow. I did not know any of this. And the facts are pretty much at the very edge of comprehension. What an amazing universe, and kudos to the folks that can understand all of this and try to explain it to us!

    Liked by 1 person

  3. Jeff Barani says:

    Very pleasant video and very instructive about neutron star.
    Thanks for sharing 😉
    Jeff Barani from Vence (France)


  4. Suchendra Narayan says:



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