The observed expansion of our universe allows us to see galaxies as they were when our universe was younger. …
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	How Big Was the Interstellar Cloud From Which Our Sun Formed?
The giant molecular clouds from which stars form tend to have masses of about 10^4 solar masses of gas…
 
	What Causes a Supernova Explosion?
You can find a nice description of the supernova process on the NASA Space Place. When a massive star…
 
	Can a White Dwarf Star Be Used as an Energy Source?
Since the energy from a White Dwarf star is derived from the stored thermal energy from its past thermonuclear…
 
	How Are Elements Heavier than Helium Formed?
Elements heavier than Helium are synthesized in a number of environments. For elements that are lighter than Iron, those…
 
	Cepheid Variable Stars as Cosmic Distance Rulers
It is the period-luminosity relation for Cepheid variable stars that provides a measurement of the absolute magnitude. You will…
 
						