NASA Astronomy Picture of the Day Collection
Emission and Reflection in NGC 6559
Bright gas and dark dust permeate the space between stars in a nebula known as NGC 6559 [ http://robgendler.a ]. The gas, primarily hydrogen [ http://pearl1.lanl. ], is responsible for the diffuse red glow of the emission nebula [ http://antwrp.gsfc. ]. As energetic light from neighboring stars ionizes interstellar hydrogen [ http://antwrp.gsfc. ], protons [ http://www.neutron. ] and electrons [ http://www.aip.org/ ] recombine to emit light [ http://imagine.gsfc ] of very specific colors [ http://csep10.phys. ], including the red [ http://antwrp.gsfc. ] hue observed. Small dust [ http://antwrp.gsfc. ] particles reflect blue starlight efficiently and so creates the blue reflection nebulosity [ http://antwrp.gsfc. ] seen near two of the bright stars. Dust [ http://nedwww.ipac. ] also absorbs visible light, causing the dark clouds [ http://antwrp.gsfc. ] and filaments [ http://antwrp.gsfc. ] visible. NGC 6559 [ http://www.aao.gov. ] lies about 5000 light-years [ http://starchild.gs ] away toward the constellation of Sagittarius [ http://www.astronom ].
Credit and Copyright:
Robert Gendler [ mailto:firstname.lastname@example.org ]
Goddard Space Flight Center (GSFC)
New General Catalogue (NGC)
Link To Source