148 High-Mass Stars

High-Mass Stars have a very-short life when compared to low-mass and intermediate-mass stars. In high-mass stars, the fusion process includes heavy elements, the CNO Cycle; C arbon- Nitrogen- O xygen:H 2 → He → C → N → O → … → Fe

High-mass star characteristics include:

  • Very high-core temperatures
  • Crushing stellar-core pressures
  • Very big and very bright,
  • Ends its stellar life with a bang.

An example of a high-mass star is the red supergiant Betelgeuse; it is 500 times the size of our Sun.

This supernova occurred about 168,000 ly from Earth.

Image of Supernova 1987a, outshines an entire galaxy; the brightest seen from Earth since the invention of the telescope. Dominating this picture are two glowing loops of stellar material and a very bright ring surrounding the dying star at the centre of the frame. Although Hubble has provided important clues on the nature of these structures, their origin is still largely unknown.
CC BY 3.0 | Image courtesy NASA and ESA

High-mass stars have lives of 10 million years, versus 10 to 50 billion years or more for low-mass stars. At the end of a high-mass star’s fusion process, iron composes the star’s core. No nuclear fusion of iron is possible out of a high-mass star core, which has the same mass as our entire Sun. The pressure at the star’s iron-laden core continues to build until the ultimate cosmic fireworks occur: a supernova.

A supernova is an explosion of a star that briefly outshines an entire galaxy, radiating as much energy as an ordinary star like the Sun over its entire lifetime. The supernova will fade from view over several weeks to months.

The star’s core collapses in an instant into a sphere; it simply cannot withstand the immense pressure and gravitational attraction. At collapse a sphere of Neutrons remains. Heavier elements are now produced due to the supernova event, and enormous amounts of energy released. An average high-mass star supernovae within 30 ly of Earth pose a danger to life on Earth, due to the energy and particles released in this type of supernova event. Particles released by the supernova are very harmful to life as we know it. It would be much like being close to an atomic bomb going off.

The Crab Nebula ; M1, a Supernova Remnant.

Image of A white region traces the cloud of energetic electrons trapped in the star’s magnetic field.
Public Domain | Image courtesy of NASA.

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