... Credit: Michael Bessell ( RSAA, ANU ), MSO Explanation: The nebula surrounding bright star S Mon is filled with dark dust and glowing gas. ... The above picture , in representative color , isolates the northern part of a greater nebula designated NGC 2264 , which lies about 2500 light-years away and includes the Cone Nebula . ... A small group of stars surrounds S Mon , the brightest star in the picture and a star visible with the naked eye toward the constellation of Monocerus . ...