Lagoon Nebula (down) Trifid Nebula (up)  in the constellation Sagittarius.
The Lagoon Nebula is estimated to be between 4,000-6,000 light years from the Earth. In the sky of Earth, it spans 90′ by 40′, translates to an actual dimension of 110 by 50 light years. Like many nebulas, it appears pink in time-exposure color photos but is gray to the eye peering through binoculars or a telescope, human vision having poor color sensitivity at low light levels.  The Trifid Nebula was the subject of an investigation by astronomers using the Hubble Space Telescope in 1997, using filters that isolate emission from hydrogen atoms, ionized sulfur atoms, and doubly ionized oxygen atom. The images were combined into a false-color composite picture to suggest how the nebula might look to the eye.

Camera : SBIG STF-8300M (cooled at-5C)
Telescope/Lens : Takahashi FSQ-85ED (450mm f/5.3)
Filter : Astrodon Ha, SII, OIII
Tracking Mount : Takahashi EM-11
Autoguide : SBIG SG-4

Total Exposure Time : Ha-72mins, SII-105mins, OIII-75mins
w Dark Frames, Bias Frames
process w CCD stack,PI, PS5

Autor: Vincent Vegabort

AstroPhotography of the day by SPONLI
6 January 2014

We select the best works of amateur astrophotographers with details of equipment, shooting processing etc.