Life Cycle of Stars: Part 2

Last time, we learned about part 1 of the life-cycle of stars, which consisted of a nebula, a protostar, low & medium mass stars a red giant, a white dwarf, and finally a black dwarf.

Stars can take two different paths in their life-cycle, the first path being the one discussed in Part 1. In Part 2, we will discuss the second path, which consists of a super red giant, a supernova, a neutron star or a black hole.

Note: The images used below may not be true visuals of what objects look like in space.

High-Mass Stars

A high-mass star is essentially a star with a mass that is several times bigger than our Sun (a medium-mass star). An example of a high-mass star is the red giant Betelgeuse in the constellation Orion. A protostar must reach 10 million Kº in order to be classified as a high-mass star, but it is important to note that not all protostars will reach 10 million K depending on how fast they reach it.

Red Supergiant

A red supergiant is, in essence, the same concept as a red giant, except that the star is formed from a high-mass star, therefore, it is called a supergiant. Researchers have not found a single number to express the approximation of mass for a red supergiant, but it can be estimated to be several times bigger than the mass of the Sun. To visualize, think of a red supergiant as a redwood tree and a red giant as a regular office building, and our Sun as the size of a bush.

Supernova

A supernova is also similar to a planetary nebula, except that the explosion occurred on a larger scale (supernova). A supernova, according to ck12, is “the massive explosion of a star accompanied by emission of light and matter so intense that it can outshine an entire galaxy”.

Neutron Star or Black Hole?

Just as a white dwarf is left over after a planetary nebula is formed, a neutron star remains after a supernova. Essentially, neutron stars are spheres of neutrons that were a result of the iron core of the supergiant collapsing in on itself. A neutron is one of the three particles that make up an atom with no charge (protons are positive, electrons are negative, and neutrons are neutral). They tend to be approximately 10 miles

in diameter (about 0.5 hours of driving time on Earth!). They are also dim, but at the same time, extremely hot (in this scenario, color does not correlate to temperature). Neutron stars can also exist in a binary system, just like regular stars! A binary system is when two bodies circle around each other. Essentially, it is a system in which two bodies are chasing after each other like rolling balls, instead of orbiting one central mass. In fact, according to lumenlearning, “About 5% of all neutron stars are part of a binary system”.

A pulsar is a pulsating radio star that is also classified as a type of neutron star. When they were discovered in 1967 by Joycelin Bell, pulsars were originally referred to as ‘Little Green Men’, because of the radiation that would be released from the pulsar.

If the star does not become a neutron star, it will be a black hole. As a low & medium sized star becomes a black hole, a high-mass star can become a supermassive black hole. An example of a supermassive black hole is Sagittarius A*, a black hole that lies in the center of the Milky Way.

Zombie Stars

Although there has yet to be any serious and in-depth research on Zombie Stars, Astronomers have indeed found that they do exist in Space. Zombie Stars form when white dwarfs survive the explosion and do not transition into the black hole stage. Normally, white dwarfs contain lighter elements like carbon and oxygen, but Zombie Stars have heavier elements like Iron and Neon. Traces of Magnesium, Sodium, and Aluminum have also been found in these unusual stars. According to an article by Scientific American, “As a white dwarf siphons matter from a companion star, it grows both heavier and denser.” Just as a zombie is supposed to be dead and gains energy from eating other living creature’s brains, Zombie Stars ‘eat’ matter from nearby stars, causing elements to fuse together and form those heavier elements mentioned above. We encourage you to do more research and learn more about Zombie Stars!

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Thank you for reading our blog all the way to the end! We hope you learned something new about the life cycle of stars. Make sure to like, comment, and share! We’re also on Instagram @midnight___eclipse. You can find us through search or by clicking the Instagram icon on the top right corner! As always, keep gazing skywards!

Bibliography

CK-12 Foundation. (2020, April 20). Life Cycles of Stars. Retrieved April 23, 2022,

Hall, S. (2019, February 21). Zombie Stars Shine On after Mystery Detonations. Scientific American. Retrieved April 24, 2022

Florida State College at Jacksonville. (n.d.). Neutron stars | Introduction to Astronomy. Lumenlearning. Retrieved April 24, 2022, from https://courses.lumenlearning.com/atd-fscj-introastronomy/chapter/neutron-stars/