Answer:
include the movement of galaxies and the chemical composition of the sun.
Step-by-step explanation:
To estimate the age of the universe and stars, astronomers observe and evaluate the movement of galaxies and the composition of the sun.
Galaxies are formed by clusters of various celestial bodies, mainly planets, stars, cosmic dust and other astronomical elements that are in a common center. The force of gravity is mainly responsible for the union of the components of a given galaxy.
The Sun, in turn, is composed mainly of the elements hydrogen and helium, but it also has other elements such as iron, nickel, oxygen, silicon, etc. Its energy is created in the deep zone of the nucleus, with very high temperature and pressure and there are nuclear reactions. Studies carried out by scientists have found that 700 million tonnes of the hydrogen element are turned into ashes of the helium element, exactly every second.