About The Foundation For Supernovas, The Concept Of A Supernova, And What Supernova Remnants Are
This research paper will briefly introduce the reason behind the death of stars to set the foundation for supernovas, the concept of a supernova, and finally more specifically focus on what supernova remnants are. It will include research about their existence, how they behave, their classifications, what is known of them, and some recent findings about supernova remnants. Within these findings will be concepts such as the four stages a supernova goes through and the three variations in the types of supernova remnants that exist. Finally it will give a brief analysis of the M1 remnant that Charles Messier documented in his Messier Objects.
Death of a Star
Before delving deep into the phenomena that are supernova remnants, it is necessary to briefly explain matters such as how and why a star dies. Stars use up all of their “fuel.” This fuel is simply burning hydrogen. Whether or not a star will become a supernova depends on its mass (Gunn 2020). Therefore, lower mass stars will not be relevant to this paper as they do not become supernovas. High mass stars do.
Each star has two forces that act upon it pushing outward is the thermal gas that the star produces. Conversely, gravity tightly pulls inward towards the core of the star to give it its structure. These two forces act in a sort of tug-of-war until A star’s energy has run out. This is determined by how a star will burn certain elements of increasingly heavier density. A star cannot burn up to iron and will begin to destabilize at this point (Freudenrich 2020). The force of gravity wins the game of tug-of-war.
Without its fuel and the star’s core destabilized, it will begin to rapidly heat up and expand continuously. This process of shrinking and heating will continue until a star explodes as a supernova – the brightest explosion in the universe. Supernovas are so bright they can outshine entire galaxies for days or even months. A supernova occurs when a star is at least five times more dense than the sun (NASA 2019). Low mass stars do not turn into supernovas, hence why they are not relevant to this paper. When supernovas finish their explosion they will either turn into a neutron star of black hole depending on their mass.
What Are Supernova Remnants?
The aftermath of a supernova’s explosion will be supernova remnants. This is different from the star itself, which will take one of the two paths previously mentioned. The supernova remnants will burn as much energy as the sun has in three million years in just one day. (Mathis 2019).
Supernova remnants are important as they serve as a means of heating galaxies through their gas. This is done through their shocks and magnetism they produce after an explosion.
There are four main stages to a supernova remnant (Mathis 2019). The first stage is the initial explosion leading into a rapid expansion of the gas across the galaxy. This gas is millions of Kelvins hot and is only observable through X-rays. This first stage is capable of persisting for several centuries.
The second stage of supernova remnants begins when the temperature begins to cool as infinitesimal energy is sacrificed. For thousands of years this energy further expands at a lower temperature into the rest of the galaxy.
When the shell of the remnant acquires material that its mass is greater than or equal to itself, the third stage has been entered. This stage lasts for hundreds of thousands of years as it continues to radiate the beautifully colored energy and gas in the galaxy.
Finally, the fourth stage is reached when the remnants are no longer discernible as something unique and independent from the galaxy. It will reach pressure that is equal to that outside of its reach. Thus, concludes the life of supernova remnants.
There are three types of classification that supernova remnants fall under. The third category is an amalgamation of the first two and each is based on a specific property that is possesses. The first type are the shell-type remnants. These types of supernova remnants are characterized by how when they expand through their own galaxy they will heat up and energize things that they come into touch with. With this chain reaction unfolding, a sort of “shell” forms throughout the galaxy giving it its name. (Nasa n.d.)
A famous example of a shell type supernova remnant is the Cygnus Loop. It is estimated to have been created 5,000 years ago and has a distinct blue tinge to it. It is clearly a shell type remnant because “The filaments of gas and dust visible here in ultraviolet light were heated by the shockwave from the supernova, which is still spreading outward from the original explosion.” (NASA 2016).
The second type of supernova remnants are the crab-like remnants. They are denoted by their shape that can look like a ring. They emit various forms of energy like x-rays, the visible light spectrum, and even radio waves. The crab nebula is a famous example of this one, which has a purple hue to it.
Finally there are composite remnants which are simply a mixture of the shell and crab-like supernova remnants. They possess qualities of both.
The Crab Nebula of the Messier Marathon
Long ago in the eighteenth century lived a French astronomer by the name of Charles Messier. Messier would often stare into his telescope in the hopes of finding comets and other objects. When he stared into his telescope one night he discovered what he perceived to be a comet but in reality was simply a cluster of stars. He knew this as it was not moving. (Bakich 2020).
Messier began to publish a variety of things that he would refer to as nuisances when someone was searching for comets in the night sky. With all of his work documented, amateur and seasoned astronomers alike have come to use his 109 document “Messier Objects” of clusters, planets, and other astronomical objects to aid them in their own personal studies. By now the question has likely arisen as to why star clusters and French astronomers are worth noting in a term paper about supernova remnants. The answer is that the first of the 109 objects that Messier documented was in fact a supernova remnant – the Taurus M1 as it is known. In fact, it was the only supernova remnant that Messier noted on his list of nuisances in the sky.
Above is an excerpt of the table found with the article detailing Messier’s findings. These details are worth some analysis about this constellation. The Messier Number for starts is simply its name. “M1.” It is derived from Messier’s last name starting with an M and that it was the first object he found in the night sky that he deemed worthy to be called a nuisance. There isn’t much to speak of there.
The NGC number is another form of classification. NGC stands for New General Catalogue. It was a system of classification created by a man named William Herschel after he and his sister pursued their ambitions of astronomy. It encompasses many different stars and objects in the sky. (Goldstein 2018). There is also not much to say of this without diverting from the topic of supernova remnants.
Skipping over the constellation classification of “Taurus” due to its obvious meaning that is it in the constellation of Taurus, its type of SNR will be explained next. SNR simply stands for “Supernova Remnant,” not to be confused with the “Signal-to-Noise” ratio that is used to measure magnitudes.
Following into magnitudes, the magnitude of this supernova remnant is 8. This means that the human eye alone cannot see this and it must be looked at through the use of a telescope. This system of classifying was derived from an ancient Greek by the name of Hipparchus of Nicea walking out one night and classifying stars into categories based upon how bright that they are (Mihos n.d.). The brightest stars were given the lowest numbers and the brightest the highest. Given that this star is beyond the scope of human sight, it is clear astronomers have had to state it is less luminous than a value of six. With further advanced telescopes, interpretation, and research, it is safe to assume that the crab-like remnant in the Taurus constellation has an apparent magnitude of eight.
This paper explored the factors that lead into a supernova remnant’s existence – the death of a star and a supernova’s explosion. Afterward it elaborated on the phases and types of supernova remnants that are present in our universe. Things like the crab-like remnants or the shell types to name two of them. Finally it was noted that the French astronomer of the name Charles Messier was lucky to number a supernova remnant in the Taurus constellation as the first of his Messier Objects. Deeper analysis was given based off of what Charles Messier’s M1 object’s properties were. Its classifications and it magnitude. Supernova remnants are both ephemeral and primordial in some cases. These phenomena are truly both beautiful and mysterious.
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