deletions | additions       diff --git a/Hydrogen_is_the_fuel_for__.tex b/Hydrogen_is_the_fuel_for__.tex  index b586731..9f395b9 100644  --- a/Hydrogen_is_the_fuel_for__.tex  +++ b/Hydrogen_is_the_fuel_for__.tex 
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Hydrogen is the fuel for galaxies to produce stars. Large amounts of hydrogen gas found in various nebulas and galaxies are compacted and form stars, where nuclear fusion takes place. For a galaxy to produce new stars it must have fuel, and in galaxies where hydrogen is abundant many new stars will continue to form. An example of a hydrogen rich environment is a starburst galaxy where new stars are being formed and is NGC 1792 in the Columba constellation.   However, when galaxies lack the necessary fuel to produce stars they are considered to be H1 deficient. NGC 4921 is an example of an H1 deficient galaxy.Searching for objects within 750 kpc and 500 km/s near NGC 4921 with NED returned a staggering 73 objects, which means it is probably part of a large cluster.  Sidney Van den Bergh, the astronomer who discovered the galaxy described it as "anemic" because of the low rate of star formation. When examined, NGC 4921 was found to be strongly H1 deficient.