Tag: Crescent nebula


Cygnus is a prominent constellation in the northern hemisphere’s summer and autumn skies. Known as the “Swan,” it is easily recognizable due to its distinctive shape, which some people interpret as a flying bird with outstretched wings. In Greek mythology, Cygnus is often associated with the story of Zeus and the transformation of his lover, the beautiful mortal named Leda, into a swan.

The constellation Cygnus is home to several interesting celestial objects. One of the most famous is the Northern Cross, a prominent asterism formed by the brightest stars in the constellation. Deneb (upper right corner), is the brightest star in Cygnus.

In addition to stars, Cygnus contains various deep-sky objects. The North America Nebula (NGC 7000) and the Pelican Nebula (IC 5070) are two emission nebulae located in the region of Deneb. These nebulae are often photographed due to their striking shapes, resembling the continent of North America and a pelican, respectively. Moreover, two supernova remnants can be found in this constellation. The Veil Nebula (upper left) knows probably every amateur astrophotographer, but to find out that there is another remnant called LNB 147 (lower left) was a surprise for me. This one deserves more attention, and if the weather allows, I will try to capture more light coming from there.

Cygnus is also traversed by the Milky Way, making it a rich region for observing star clusters, nebulae, and other deep-sky wonders. Overall, the constellation Cygnus holds a special place in both mythology and astronomy, offering stargazers a captivating celestial experience.

The pictures are a mosaic of 3×4 frames. In total, I captured 342 frames, each 5 minutes long (integration time 28 hours 30 minutes), which were taken during 10 nights in August and September. This makes it my biggest astrophotography project so far.

TelescopeAskar ACL 200 F4
Aperture50 mm
Focal length200 mm
MountRainbow Astro RST 135
AutoguidingZWO 178MM, QHY Mini Guide Scope
CameraZWO 6200MC @-10°C
FiltersAntlia ALP-T Dualband 5nm
Exposure342x300s, Gain 100, bin 1×1,

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,

NGC6888 Crescent Nebula

Another cloudless night and I decided to test the IDAS NB1 filter again This time on Crescent Nebula, located in constellation Cygnus. The nebulosity was captured well and it’s comparable to the narrowband image I captured a long time ago. However, the bright stars are surrounded by ugly reflections. I am not sure it’s due to the MaxField coma corrector or the filter. Next time I will try with ExploreScientific coma corrector and we will see.

TelescopeNewton 254/1000 mm
Aperture254 mm
Focal length950 mm
MountGemini G53f
AutoguidingZWO 174MM, TS 60/240 mm
CameraZWO 071 Pro @-5°C
CorrectorMaxField coma corrector
FiltersIDAS NB1 Nebula Filter
Exposure103x180s, Gain 95, bin 1x1,

NGC 6888 Crescent Nebula

Crescent Nebula, also known as NGC 6888, is a HII region, hot ionized hydrogen gas cloud. The nebula got the shape by high speed stellar wind of Wolf-Rayet star, which is colliding with slow moving mass, ejected by this star during transformation into a red giant. The nebula is approximately 5000 light-years away from us and it can be located in constellation Cygnus.

The picture is the last one from 6.9.2018. In the evening I captured Omega nebula, M80. As a last deep space object I pointed on Crescent Nebula, started auto guiding and went to sleep. Therefore the picture is a stack of 64 pictures; each has 3 minutes of exposure time, thus total integration time 192 minutes.

Technical details:

TelescopeNewton 150/600 mm
Aperture150 mm
Focal length660 mm
MountiOptron CEM25P
AutoguidingQHYCCD miniGuideScope 130 mm f/4.3, ZWO 174 MM
CameraZWO 071 Pro @-10C
CorrectorExplore Scientific HR coma corrector
FiltersAstronomik L-1 - UV IR Block Filter
Exposure64x180s, Gain 134, bin 1x1,

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.