Solar system
作者：María López Patón
1. galaxies
1.1. eliptical galaxy
1.1.1. spiral galaxy
1.1.1.1. barred spiral galaxy
1.1.1.1.1. irregular galaxy
2. stars
2.1. are large balls of gas wich produce and emite grat amounts of energy .
2.1.1. tyoes of stars
2.1.1.1. stellar nevula
2.1.1.1.1. protostar