1.   Astronomers theorize that these isolated stars were displaced from their home galaxies as a result of galactic mergers or tidal forces from nearby galaxies.

2.   Lead piece is about a gigantic black hole that lurks in the dust-shrouded heart of our home galaxy, the Milky Way.

3.   Travel through star fields of the Milky Way, our home galaxy, and the billowing clouds of gas and dust where new stars are born.

4.   Some believe the bursts come from within the halo of objects that surrounds the Milky Way, the home galaxy of the solar system.