in Serpens Cauda was worthy of ten plus pages of photos and commentary in Burnham's. M16 is at about 8000 ly and is roughly 70 ly in diameter. The most prominent feature is the various dark projections all oriented towards the center of the nebula. Fred Hoyle believed the nebula was a rapidly expanding hot gas cloud colliding with the cooler gases in the projections. Hubble Space Telescope images of the dark projections support Hoyle's description of the interaction.
Foresthill, California
FS-128 (ag)
hPJ400, 45 minutes
July 1999