A variety of stars and nebulae can be found towards the constellation of Sagittarius. Dense fields of stars laced with dark lanes of dust crowd this region only a few degrees from the center of our Galaxy. Prominent nebulae include the red Lagoon Nebula (M8) in the center and the multicolored Trifid Nebula (M20) in the upper right. Another one, NGC 6559, is at the left of M8, separated from the larger nebula by a dark dust lane. All three are stellar nurseries about five thousand light-years or so distant. In this digital composition, the dominant red color of the emission nebulae is due to glowing hydrogen gas energized by the radiation of hot, young stars. The contrasting blue hues, most striking in the Trifid as well as NGC 6559, are due to dust reflected starlight. The bright HII region left of the Trifid is Sh-34 while the one closest to the bottom right corner is Sh-22. Also visible over Sh-34 the rainbow trace left by an asteroid. Almost at the center of this image is the open cluster M21 (text adapted from APOD).
Pentax 67 EDIF 300mm f/4 - FLI Proline 16803 - Ha (120m) R (40m) G (40m) B (40m) - Warrumbungle Observatory, Coonabarabran, NSW, Australia