Narrowband

Crescent Nebula in HOO + RGB Stars

This is NGC 6888, the Crescent Nebula. Wikipedia:

"It is formed by the fast stellar wind from the Wolf-Rayet star WR 136 (HD 192163) colliding with and energizing the slower moving wind ejected by the star when it became a red giant around 250,000 to 400,000 years ago."

Most of the visible emission is from hydrogen, I capture a bit of oxygen but the sulfur signal was so weak I didn't use it. About nine hours total of narrowband integration time, plus another hour and a half of normal-color frames to yield natural-color stars.

Crescent Nebula in HOO + RGB Stars

This is NGC 6888, the Crescent Nebula. Wikipedia:

"It is formed by the fast stellar wind from the Wolf-Rayet star WR 136 (HD 192163) colliding with and energizing the slower moving wind ejected by the star when it became a red giant around 250,000 to 400,000 years ago."

Most of the visible emission is from hydrogen, I capture a bit of oxygen but the sulfur signal was so weak I didn't use it. About nine hours total of narrowband integration time, plus another hour and a half of normal-color frames to yield natural-color stars.