The end of a high mass star: Pulsars and Neutron Stars

Like we have learned in class, many of the stars found in the universe have similar properties to our own star, the sun. However, some stars are different and like we learned in the star formation unit and these stars are of high mass. These special stars are destined to end in supernovas. Compared to our sun they are 10x heavier and 4x as large. Due to this high mass, their fuel is burned at a greater rate, in about 10 million years. One can put into perspective this with our own sun whose hydrogen will  burnt out after 10 billion years, the difference is clear. When this happens to our stars like our sun, they become a white dwarf: small, dense, and whose temperature cools down eventually. These high mass stars on the other hand no longer support the outward pressure that balances with their inward gravitational pull its immense mass requires. Compared to the slow and calm death of the other stars, the death of this high mass stars becomes much more dramatic. The core shrinks, burns up in temperatures to about 100 billion degrees and becomes more dense with the iron atoms crushing together. This dramatic explosion of energy lead to a shocking wave that expands to about 1 billion kph. This is the death of the high mass star, this is a supernova.  The material pushed away by the explosion forms into a ring shape known as the supernova remnant. What remains from the original high mass star in a much smaller dense core of only neutrons, known as a neutron star. If the neutrons radiate, a pulsar forms. However, something else could happen. If the original high mass star was greater than 15x the sun, the neutrons would not survive the collapse of the core and the stars would become black holes.

The following diagram, visually demonstrated the life cycle of a high mass star:






  

APOD 3.8

This week's APOD is titled Glubules in the Running Chicken Nebula. The title was interesting so that's why I picked. This nebula is named after it's shape. The image was taken from an observatory in Australia called the Siding Spring Observatory. The globules in the nebula are called Thackeray's Globules (pictured below). These globules referred to as egg are potential sites for the gravitational condensation of new stars. I thought this was a pretty since we just recently learned about the formation of stars so I  understand how it occurs. I also decided to choose this APOD because I was able to see the chicken head and found it amusing. I am also intrigued by the visualization of nebulas in photos. I find it very impressive we can see them and photograph them with the telescopes we have.