SUNSET: 
0
Photographer:
Hal Heaton
Location of Photo:
Chilescope, Telescope 4
Date/Time of photo:
August 8, September 11 and October 7, 2020 (moonless)
Equipment:
Camera: Unguided FLI Microline 16200 fitted with a Nikkor 200:2 lens (100 mm aperture, f/2); Filters: Astrodon L, R, G, B, H-alpha and OIII; Exposures: 180-sec broadband, 300-sec narrowband stacked for 27, 6, 6, 6, 30 and 30-mins, respectively; Plate Scale: Unbinned, 6.3 arcsec/px.
Description:
Laced among some of the most spectacular star fields in the Milky Way, the star-forming nebulae Sharpless 2-54 (top, Lynds Bright Nebula 018.45+01.87), M16 (the Eagle Nebula, center), and M17 (the Omega Nebula, bottom) span the opaque dust-laden central rift in the first quadrant of the Galaxy. Glowing in the rich red H-alpha emission produced when electrons recombine with ionized hydrogen atoms, the brightest regions in the latter two are sufficiently energetic to additionally excite copious amounts of blue-green light from doubly-ionized oxygen atoms (OIII). When superposed with the deep red H-alpha radiation, these regions appear whitish. This widefield image spans 7.8 x 6.2-deg on the sky, and is oriented to place north up and east to the left.
