Apr 17 2016

The death of stars

Stars inevitably run out of fuel to burn in the nuclear fusion reactions that burn in their cores and when this happen there are a number of spectacular events that occur in their death throes. As a star goes through its main sequence stage it burns hydrogen into helium through nuclear fusion. As it starts …

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Aug 05 2015

What are the different types of stars?

In my last few posts I have talked mainly about the Sun, our closest star but what other types of star are there? Clearly by looking at the Hertzsprung-Russell diagram there are different types; cooler, dimmer smaller stars to brighter, hotter and massive stars. Astronomers class the stars according to a property called it’s Spectral …

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Jul 29 2015

Where is the Sun on the H-R diagram?

In one of my earlier posts I described a Hertzsprung Russell diagram which shows the relationship between a stars temperature and its luminosity. But where does our Sun sit on this diagram? Our sun sits squarely in the main sequence line. The main sequence makes up the majority of a stars life when it is burning …

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Mar 20 2015

The Solar Eclipse

Today, 20 March 2015, there was a solar eclipse in the very northern hemisphere. You could see between 85%-95% eclipse in mainland Britain but you would need to further north to the Faroe Islands or Svalbard to see a total eclipse. Here is Bristol I attempted to get some photos using a solar film cap …

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Oct 08 2014

H-R Diagrams

I described stars in my last post and I talked about two that are different colours; Rigel and Betelgeuse in the constellation of Orion. Rigel is a blue super giant and Betelgeuse is a red super giant but what is the Sun, how do we classify stars as super giants and what other types of …

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Jul 21 2014

What are Stars?

Stars are all those little pin points of light in the night sky that slowly move around the sky throughout the year, but what exactly are they? Stars are the furnaces of the universe; a single star is a huge collection of matter that is gravitationally pulling itself together into a sphere and this gravitational …

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Jul 16 2014

Forces of Nature – The Weak Nuclear Force

The weak nuclear force is indeed the weakest of the four forces of nature. It is responsible for the nuclear decay of atoms and there are three types of decay that take place: 1) Beta minus decay – A neutron decays into a proton and emits an electron and an electron anti neutrino. 2) Beta …

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Jul 09 2014

Forces of Nature – The Strong Nuclear Force

The strong nuclear force is indeed the strongest of the Four Forces of Nature, but it only works at the heart of the atom and has a very small range, just 10-16 metres. This range is only just bigger than a proton or neutron and it comes from the gluons that hold the innards of …

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Jul 02 2014

Forces of Nature – Electromagnetism

The electromagnetic force bears some resemblance to gravity in that it is infinite and obeys the inverse square law. However, this is where the similarities end. The electromagnetic force is 10^43 time stronger than gravity and, more importantly is has both a positive and negative charge. This positive and negative charge lead to important implications …

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Jun 14 2014

Forces of Nature – Gravity

Plot of the inverse square law of gravitational attraction. (C) Chris Hall 2014. All rights reserved.

Gravity is the most obvious of the four forces of nature. It is what holds our feet on the ground, the atmosphere in place and keeps Earth orbiting the Sun but gravity is an attractive force only, anti gravity is the subject a science fiction. Gravity has an infinite range but is the weakest of …

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