38.The center of our galaxy believed to be occupied by : 1777260
38.The center of our galaxy is believed to be occupied by the radio source known as ____________________.
39.The ____________________ of the galaxy contains population I stars, open clusters, and gas clouds.
40.____________________ are groups of 100,000 to 1,000,000 population II stars firmly bound by gravity.
41.In the diagram below, the approximate absolute magnitude of a Type II Cepheid with a period of 30 days is ____________________.
42.The rotation curve of the galaxy provides evidence for the existence of the ____________________ which extends beyond the halo of the galaxy.
43.Henrietta Leavitt discovered the period-luminosity relationship for ____________________.
44.Globular clusters are primarily found in the ____________________ component of the Galaxy.