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.
A) Spiral arms contain young stars, dust and gas within which star formation continues, whereas globular clusters contain older star populations, with no dust, gas or on-going star formation. The disk of the Milky Way appears bluish because of the light from the many O and B type stars found there.