What is a Supernova? Pt.1

So…What is a supernova? What are these intense energy explosions that radiate and emanate throughout the Universe? To answer this question In this instance well focus on the type II supernovae SNII as this is the start that died. But your probably wonder what a supernova Class I is (SNI).  In this instance the classifications that are used to describe supernovae and their properties bear no real physical significance. But to generalise, what the classifications mean, boils down to their spectra (Spectrometric properties), So for example would be that when a dying star is ready to explode, the explosion and the remnants from the explosion are analysed spectrometric ally. It is these precise chemical characteristics that determine which bracket to place the particular supernova into. Like whether an absorption line is shown in a spectral analysis. Though normally when you discover a type I SN. Normally it is similar in most ways to that of a white dwarf, though still accreting matter and slowing perishing in the cold voids of space eventually collapsing into itself. The SNI has to hit a certain threshold, a mass threshold called the Chandrasekhar limit. The maximum mass allowed for a white dwarf to be at, to avoid going supernova. A SNII is a final death phase, where the star has reached the end of its life.

 

 Fig.1 A extra terrestrial nebula that habits around Wolf-Rayet star (WR124)

Credit: van der Sluys, M,; Lamers, H. J. G. L. M. (2003).

 *Note: This Nebula is 21,000 light years across

So, now you probably asking, why and how does a star collapse in on itself? At first thought, it would seem like a difficult answer, but actually is quite the contrary.  Gravity as usual, tries to pull anything down towards the particle or object with most matter/density. For us to let go of a cup of tea in free space only for gravity to intervene and pull it straight down to the ground, likely breaking it and causing a mess. In that situation there is nothing stopping the cup from falling to the Earth, no force or energy to keep it in check. With Stars its similar, though there is a difference, energy! Energy is actually a factor with a star and gravity. With the hydrogen and helium inside burring away in a nuclear fusion reaction, intense energy is keeping gravity from crushing the star into oblivion. Now, when the star dies, meaning when it has no more hydrogen to burn and the fusion reaction is essentially gone, gravity steps in to do its business, crushing the star into its inner most core. Then the centre of the star then collapses on itself.

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University Guide

I have decided to research the different universities that offer Physics degrees and Physics related degrees. The mission statement is to give prospective high-school/secondary school students the opportunity to properly research the University that suits them best. I will be covering modules that they cover. Reviews of the university, not from newspapers or on-line websites but from the people that matter. The students & graduates that came from these universities. I will be including a ranking system( perhaps a crude one) where I will have the top 10 Universities for Physics in the US, UK and Asia. I will have a Ranking system for the 20 Best Universities in the World and have a list on what topics best suits these universities. For example, the university of South Hampton would be know for Black Hole research in the UK and in Caltech and so on. Just to note that this is actually for me as-well as the reader as I am generally interested in which Universities offer the best courses  for the student. I know most students will not know what field they would like to be in in Physics, but some do or at least have a general ideal. Some might want to be in fluid dynamics, some in Astronomy and others in particle physics. This guide is for them essentially, but this can be used by others to ascertain which universities would be best for physics and which will suit them. As to avoid hefty financial mistakes. I will be inserting college fees to each university rank, if and when I can find them. I will ofcorse have links to their respective pages so you can obviously clarify yourselves from more official sources. It is essentially, to allow you the view to find out which universities you should be looking at and also where some of the great scientists or our time and before then have studied and come to greatness.

Just to mention, that some of the information at time of print will be in date, but I might or might not update it. I will see how things go, If I can get a chance to do it, I will. You can always contact me if you have any questions on the matter.

This will come in time and will be a building process.

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Necessary Ingredients Detected in the Milky Way for the formation Black Holes Pt.II

Now as mentioned before, there is uncertainty  about the implications of the time lag, would that nebula still be the same as it was when the light left that cloud 30,000 years ago. I don’t know. Everything we look at respectively is looking in the past, the light that is coming to our eyes are images of the past. Looking at a computer screen its only a few femtoseconds to reach the screen to your eyes. As you could imagine this is not a really example and shows how insignificant it is. But if you amplify the distance considerably, then your results begin to take form.

The disk shaped clouds that were observed are about 50 light years cross . This is a massive number and in comparison to the Earth, you would not be able to see the Earth, in fact you wouldn’t be able to see the sun, except maybe for a little white dot so faint, that you would mistaken it for a dead pixel on your screen.

The leader of the study Tomoharu Oka of Keio University in Japan stated that the 50 light year across chemical cloud “revolves around the supermassive black hole at a very fast speed". Which the other clouds of clumped chemicals are increase and expanding very fast rates of about 223, 000 mp/h. This is allowing the scientists think that the super novas massive explosions were a cause of this particular expansion.  This is an interesting part, that the fast growth of the cloud is suggesting that 200 super nova have gone of inside. This cloud is assume or suggested to be only about 60,000 years of age (Not very old, relative to the cosmic age). Deducing this from the observations, it is thought that supernovae are suspected to go of every 300 years.

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Necessary Ingredients Detected in the Milky Way for the formation Black Holes Pt.I

In certain parts of the Milky Way galaxy habit molecular clouds, these thick and massive clouds of chemicals are good birth places for new stars for which nuclear fusion can commence. Scientists are searching in these regions which contain the most massive and the most densest molecular clouds. These are known to habit and surround our galaxy near the center, which has be suggested that a Super Massive Black Hole is in the centre, dictating our gravitation interaction with the galaxy and everything within it. This Super Massive Black Hole mentioned before in pervious topics, named Sagittarius A* or Sgr A*) is the lynch pin of the galaxy, making everything in and around it form in to a swirl of immense gravitational force.  This Black hole is the suns mass of about 4 millions of our Suns! That’s pretty big and you can imagine the gravitational forces that are associated with this stellar mass.

 

Fig.1 illustration of a large stellar cluster habituated near the Milky Way.

Credit: Keio University

These clouds that scientists are looking for are good places to start looking for evidence for forming stars. To analyse what is going on in these places, the use of radio telescopes are to determine the make up of these clouds and to compile a map of the density and temperatures of the molecular nebula in the center of the Galaxy. The discovery of 4 massive gas clouds that appear to be the seeds of small medium black holes. These voids in space or ultimate density. 100,000’s time more denser than the Sun are suggested to be the building blocks of SMBH’s that are thought to be in the centre of the galaxy.  

 

Fig.2 Molecular gas at the center of the Galaxy. 

Credit: Keio University

Legend: + : Sagittarius A* (SMBH)

Though these clouds are really big, they are 30,000 light years away from Earth. Though we are able to see them now. Why is that?  Well the simple answer is that light travelled to us. I have asked a few times, why if its 30,000 light years and that means that light would take 30,000 years to reach that nebula then another 30,000 light years back, wouldn’t that mean we couldn’t, realistically do anything about it. Light travelled from the nebula 30,000 years ago to reach Earth Today.

Part 2 Next

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