message board
Starburst
and Galaxy Evolution
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| Galaxies are the largest structures in the universe, varying from a few tens of thousands of light years to around 150-200, 000 light years. The Milky Way galaxy we live in is estimated to be around 100,000ly in diameter (six hundred thousand trillion miles (600,000,000,000,000,000)). If you take a look at this picture of NGC 4414 and consider that it is relatively similar to the Milky Way, try to imagine a star roughly 1/3 of the way in from the edge, this would represent the rough position of our solar system. From the picture it is fair to say that you would expect our skies to be brimming with light from very close stars, but I'm sure you are aware this is not the case, and we are in fact twenty four trillion miles from the nearest star. |
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Below is a series of images showing the different categories of galaxy.
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Stars are the fundamental building blocks of galaxies. Stars evolve - and so do galaxies. Comparison between observations and models of evolving stellar populations helps understand the star formation process, triggering mechanisms, influence of the environment, the chemical history, and processes in the interstellar gas. |
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Most stars
are individual and are separated by usually a few billion or a few
trillion miles. In many areas congregations of gravitational bound stars
group in clusters of many thousand or hundreds of thousands of stars.
The spacing of stars
decreases as they get closer to the galaxy
center, this forms star
clouds |
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In most of the images on this page there is not just one star that can be made out belonging to a galaxy, but what we see is the combined light given out by billions of stars enormously swamped by the huge galaxies in which they live. |
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Many galaxies with active current star formations show signatures of violent high-mass star formation, a phenomenon often called 'starburst'. Scaled-down versions of starbursts are found in the Local Group of galaxies, like 30 Doradus in the LMC, but prototypical starbursts are much farther away. |
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Other relevant sites of interest
www.electric-cosmos.org |
www.nasa.gov |
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www.stsci.edu |
www.dynamicearth.co.uk |
