DSLR astrophotography by Sergi Verdugo
The Eagle Nebula (M16)
Exposure: 17×600″ @ ISO 800
Telescope: Skywatcher Newton 8″ f5 with Baader MPCC
Filter: Omega Optical NPB 2″
Mount: Skywatcher EQ6 Pro
Camera: Amp-off Modded & Cooled Canon 350D
Date: 9th July 2010
Location: Coll de Jou (Barcelona, Spain)
Comments: This was my second photo done with the NPB filter. It produces good contrasty images of emission nebulae, the tradeoff is the chromatic balance of the image which is altered compared to that of an RGB image, although much less than that of false color images made with narrow band filters.
The Eagle Nebula (M16) is lying some 7000 light years distant in the constellation Serpens, close to the borders to Scutum and Sagittarius, and in the next inner spiral arm of the Milky Way galaxy from us (the Sagittarius or Sagittarius-Carina Arm) a great cloud of interstellar gas and dust has entered a vivid process of star formation. Open star cluster M16 has formed from this great gaseous and dusty cloud, the diffuse Eagle Nebula IC 4703, which is now caused to shine by emission light, excited by the high-energy radiation of its massive hot, young stars. It is actually still in the process of forming new stars.
Just in the center of the image lie some darker columns that are in fact cool interstellar hydrogen gas and dust that act as incubators for new stars. Inside them and on their surface astronomers have found knots or globules of denser gas. These are called EGGs (acronym for «Evaporating Gaseous Globules»). Inside at least some of the EGGs stars are being formed.