by Sergio Eguivar
NGC 6559 is surrounded by a complex and interesting region that includes a variety of objects located one degree west from the Lagoon Nebula. The bluish nebula next to the brilliant arc in the middle configure NGC 6559. The arc shaped cloud contains young and hot stars. It is thought that the emission of radioactivity from those stars ionized the hydrogen protons producing a prominent brightness.
Barnard 303 is the "serpent shaped" dark nebula. It starts 3 arcs minutes from the brightest star in the photograph SAO 186366 with 7.6 magnitude. B303 does not generate light, but absorbs the light of the hydrogen cloud which is more distant. This dark nebula spreads its path into 7 light years.
The image was taken 50 km away from Buenos Aires Argentina in June 2010. elestron SCT 8" working around f6.3 and a QSI 583 WS with Astronomik Type 2 + Ha 6nm . LHaRGB (25,30,30,25,35) 300 subs