... Spiral Galaxy In Centaurus . ... Centaurus, the Centaur, is one of the most striking constellations in the southern sky. The lovely Milky Way flows through this large constellation whose celestial wonders also include the closest star to the sun, Alpha Centauri, the largest globular star cluster in our galaxy, Omega Centauri, and the closest active galaxy, Centaurus A. Double Eruptive Prominences . ... A Crescent Nebula Star Field . ... What caused the Crescent Nebula? ... Mercury on the Horizon . ...