What is a supernova?

Let’s take a look at the life cycle of a star.


A nebula is a cloud of gas (hydrogen) and dust in space.

Nebulae are the birth spots of stars.


A star is a luminous sphere of gas that produces its own warmth and light through nuclear reactions (nuclear fusion).They originate from nebulae and exist for the large part from hydrogen and helium gas. Surface temperatures differ from 2000C to above 30,000 C and the corresponding colors from red to blue-white. The brightest stars have masses 100 times larger than those of the sun and emit as much light as millions of suns. They live less than a million years before they explode as a supernova. The weakest (in terms of brightness) stars are the red dwarfs, less than one thousandth the brightness of the sun.


This is a big bright star with a cool surface.It is formed during the later stages of the evolution of a star like the sun, because it has no hydrogen fuel in the middle. They are very bright because they are so large, although their surface temperature is lower than the sun, about 2000C-3000C.


These are very cool, vague and small stars, about one tenth of the mass and the diameter of the sun.They burn slowly and have an estimated life span of 100 billion years. Proxima Centauri and Barnard’s Star are red dwarfs.


This is a very small, hot star, the last stages of the life cycle of a star like the sun.White dwarfs have a mass resembling the mass of the sun, but only 1% of the diameter of the sun; About the diameter of the earth. The surface temperature of a white dwarf is 8000C or more, but because they are smaller than the sun, their total luminosity is 1% of the sun or less.


This is the explosive death of a star, and often it results in that the star obtains for a short brightness of 100 million suns.

Supernova is located in the lower left corner.


These stars are mainly composed of neutrons and are produced when a supernova explodes, which combines the protons and electrons to produce a neutron star.

Neutron stars are very dense. Typical stars with a mass of three times than that of the sun but a diameter of only 20 km. If the mass is larger, gravity will be so strong that it will shrink to a black hole. From pulsars it is assumed that they are neutron stars that turn around very quickly.


It is thought that black holes arise at the end of their lives.

Gravity in a black hole is so big that nothing can escape, not even light. The density of matter in a black hole cannot be measured. Black holes distort the space around them and can often be neighboring matter in themselves, including stars.

A very energy-rich blast from a star.If one of the nearest stars of ours (not the sun) would be a supernova (very unlikely) life on Earth for most life forms would become biwithout difficult not to say impossible.

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