Tag: NGC 6888

NGC 6888 Crescent nebula

The Crescent nebula is an HII region in the constellation Cygnus. I photographed this deep-space object before with a relatively long focal length. The Crescent nebula is not the only nebula in the constellation Cygnus. In fact, this constellation is overpopulated with either emission or planetary nebulae. This is the reason why I picked a shorter focal length than before (wider field of view), positioned the Crescent nebula in the corner of the CMOS chip, and let the photos be collected for 3 subsequent nights. In total, I exposed 153 photos, each 5 minutes long. This means nearly 13 hours of integration time, which makes it one of the longest total exposure I spent on a single deep-space image.

Hubble palette image (SHO):

Bi-color image (HOO):

TelescopeSharpstar 94EDPH
Aperture94 mm
Focal length414 mm
MountRainbow Astro RST 135
AutoguidingZWO 174MM, QHY Mini Guide Scope
CameraZWO 2600MM @-10°C
CorrectorF4.4 Quad Reducer
FiltersAntlia Ha, OIII, SII 3 nm
Exposure153x300s, Gain 100, bin 1×1,

NGC 6888 – Crescent Nebula

In an emission nebula located in constellation Cygnus (swan), 5000 light years from Earth. The nebula has 25 light years (!) in diameter. This constellation, as well as the nebula is lying on the plane of our home galaxy Milky Way. Therefore there are so many stars visible.

The picture was processed by bi-color technique – this means that the picture is assembled from two narrow band images: hydrogen alpha (Ha) and ionized oxygen (OIII). Ha was inserted into red channel and OIII into green and blue.