Definition of thanksgiving for English Language Learners. Thanksgiving : the fourth Thursday in November in the U.S. or the second Monday in October in Canada celebrated as a legal holiday for people to be thankful for what they have.
A galaxy contains stars, gas and dust. In a spiral galaxy like the Milky Way, the stars, gas, and dust are organized into a bulge, a disk containing spiral arms, and a halo.. Elliptical galaxies have a bulge-like central region and a halo, but do not have a disk.
Our sun is 25,000 light years from the center of the Milky Way. The oldest star in the galaxy is 13.2 billion years old. The stellar disk of the Milky Way Galaxy is approximately 100,000 light years in diameter and is about 1,000 light years thick. It is estimated to contain up to 400 billion stars.