Evolution

 

 

The sun is one of more than 100 billion stars in the Milky Way. It orbits some 25,000 light-years from the galactic core, completing a revolution once every 250 million years or so. The sun is relatively young, part of a generation of stars known as Population I, which are relatively rich in elements heavier than helium. An older generation of stars is called Population II, and an earlier generation of Population III may have existed, although no members of this generation are known yet.

The sun has enough nuclear fuel to stay much as it is now for another 5 billion years. After that, it will swell to become a red giant. Eventually, it will shed its outer layers, and the remaining core will collapse to become a white dwarf. Slowly, this will fade, to enter its final phase as a dim, cool theoretical object sometimes known as a black dwarf.

 

 

2018

 

 

 

2017

 

 

 

2016

 

 

 

 

2015

 

 

 

2014

 

 

 

2013

 

 

 

2012

 

 

 

2011

 

 

 

2010

 

 

 

2009

 

 

 

2008

 

 

 

2007

 

 

 

2006