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.
Spiral galaxies are hotbeds of star formation, but elliptical galaxies are deader. They contain less gas and dust, which means fewer new (and brighter) stars are born. The existing stars inside an elliptical galaxy tend to be older, giving off more red light than younger stars.