Planet Earth (where we live) is located in in the milky way galaxy. The milky way galaxy is just one of somewhere between 100 to 200 billion galaxies that exist in the universe. Experts really have a hard time agreeing on that. Most galaxies are home to least one star, but on average 100 million stars inhabit a galaxy. In our galaxy we have just one star. Our star is called the sun. You might be a little familiar with it? The sun is over 100 times wider than Earth and the largest object in our galaxy exerting a great deal of gravity on the rest of the bodies in our galaxy. Due to this gravity all planets in our galaxy revolve around the sun.
The sun is a humongous ball of gas consisting mostly of hydrogen (91%) followed by helium (8.9%). The gas molecules are in a constant state of thermonuclear fusion. This causes atoms to continually combine to form larger atoms. This process results in immense amounts of energy being released in the form of heat and light. The surface of the sun is about 10,000 degrees Fahrenheit. The internal core can reach temperatures of 27 million degrees Fahrenheit. It takes roughly 8 minutes for light from the sun to reach us on Earth.