View allAll Photos Tagged CrescentNebula
This is a one frame from a very large, 18-panels, mosaic of constellation Cygnus. More info in my blog: www.astroanarchy.blogspot.fi/2013/09/a-collection-of-imag...
NGC 6888 in HST-palette
Ra 20h 12m 7s Dec +38° 21.3′
The Crescent Nebula, also known as NGC 6888, Caldwell 27 and Sharpless 105, is an emission nebula in constellation Cygnus, about 5000 light years distance.
It is formed by the fast stellar wind from the Wolf-Rayet star, WR 136 (HD 192163), colliding to an slower moving wind ejected by the same star when it became a red giant, around 400.000 years ago.
The result of the collision is a glowing shock shell around the star. Apparen size of the shell is 18' x 12' and the real size is about 25 x 16 light years.
Image is in HST-palette, (HST=Hubble Space Telescope)
from the emission of ionized elements, R=Sulfur, G=Hydrogen and B=Oxygen.
Star colors are mixed from the NB channels, Red=H-a, G=O-III and B= 85%O-III + 15%H-a.
The crescent nebula in Cygnus is a popular and easy target for amateur telescopes. A powerful, yet dying star called a Wolf-Rayet star is responsible for this formation of glowing dust and gas, and will end its life as a supernova.
Takahashi Sky 90 at f/4.5
SBIG STL-4020M (remote guide head)
Takahashi EM-200
H-Alpha/OIII/SII: 18 x 20 minutes each channel
Processed with Maxim/DL, CCDStack, and Photoshop CS4
Noel Carboni's Astronomy Tools
Crescent Nebula: finished (for now at least). The total exposure time is over 6 hours taken over 5 nights. It would be nice to add more but I think it's now a case of diminishing returns and I'd prefer to move on to other targets. The objective was to try and get the whole shape of the object to resolve rather than just the brighter crescent part and it is just about visible although capturing it with an f12 scope was challenging. Anyway, the nebula isn't going anywhere so more data can always be added to this shot another time but really it's a target for somewhere with darker skies.
[Wikipedia] The Crescent Nebula (also known as NGC 6888, Caldwell 27, Sharpless 105) is an emission nebula in the constellation Cygnus, about 5000 light-years away from Earth. It was discovered by Friedrich Wilhelm Herschel in 1792. 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. The result of the collision is a shell and two shock waves, one moving outward and one moving inward. The inward moving shock wave heats the stellar wind to X-ray-emitting temperatures.
It is a rather faint object located about 2 degrees SW of Sadr. For most telescopes it requires a UHC or OIII filter to see. Under favorable circumstances a telescope as small as 8 cm (with filter) can see its nebulosity. Larger telescopes (20 cm or more) reveal the crescent or a Euro sign shape which makes some to call it the "Euro sign nebula".
47 x 8 minute exposures at 400 ISO (6 hours and 16 minutes)
27 x dark frames
20 x flat frames
21 x bias/offset frames (subtracted from flat frames only)
Captured with APT
Guided with PHD2
Processed in Nebulosity and Photoshop
Equipment:
Celestron NexStar 127 SLT
Skywatcher EQ5 Mount
Orion 50mm Mini Guide Scope
ZWO ASI120 MC imaging and guiding camera
Canon 700D DSLR
Well known , rich in hydrogen field in Cygnus. Taken on 05/06 May 2014 night from Southern Poland. Despite low altitude and short night I decided to capture this frame before short summer nights arrive.
35x90s
Canon 6D mod on Astrotrac
Sonnar APO 135mm @f/2.8
ISO1600
Bi-colour version of flic.kr/p/Kg2gNG , with some OIII (captured under non-ideal moonlit conditions) added as both blue and green channels. The meteor is Ha, therefore red in this palette.
I finally managed to get H-Alpha narrowband data for both Luminance and Red channels. I had Green and Blue channels from my previous shot.
Green and Blue : 21x4mn subs, darks, flats, bias using CLS filter
Luminance and Red : 21x4mn subs, darks, flats, bias using H-Alpha 12nm filter.
Canon 7D Astrodon Inside
Lens : Canon EF 28mm f1.8 @ f4.0
ISO 800
Astrotrac unguided
Stacked in DSS, processed in Photoshop.
I had not figured out before I did it how tough it was to focus with the H-Alpha filter and such a wide-angle lens... Stars were nearly invisible...
Telescopi o obiettivi di acquisizione: Sky-Watcher Black Diamond 200/1000 F5
Camere di acquisizione: Canon EOS 450D Baader modified and cooled with cold finger
Montature: Sky-Watcher N-EQ6 SkyScan EVO 1
Telescopi o obiettivi di guida: SkyWatcher Refractor 70/500
Camere di guida: Astrolumina QHY5-II Mono
Software: Pleaides Astrophoto Pixinsight 1.8, APT - Astro Photography Tool, Canon EOS Utility, FocusMax, Digital Photo Professional, DitherMaster for Canon EOS Utility
Accessori: Baader Planetarium Mark II MPCC Coma Corrector, Omegon Dual speed crayford focuser for newtonian, Home made Arduino Focuser (project ser Jolo - ascom-jolo-focuser), Bahtinov mask 8", EQMOD USB cable
Risoluzione: 2365x2840
Date: 10 settembre 2015, 11 settembre 2015, 12 settembre 2015, 13 settembre 2015
Pose:
11x429" ISO1600 -10C
46x429" ISO1600 -12C
Integrazione: 6.8 ore
Flat: ~19
Giorno lunare medio: 27.92 giorni
Fase lunare media: 3.99%
SQM medio: 21.35
Temperatura: 18.50
Centro AR: 303,042 gradi
Centro DEC: 38,350 gradi
Orientazione: 97,875 gradi
Raggio del campo: 0,513 gradi
Luoghi: In aperta campagna, Ruderi Poggioreale, Trapani, Italia
Commonly called the Crescent Nebula, Caldwell 27 looks more like a prehistoric dinosaur egg. Hubble’s vibrantly colored image zooms in on a small region of the nebula that is “only” 3 light-years across, or about 17.6 trillion miles. The cloudy, mottled shell surrounds an extremely hot and short-lived type of star called a Wolf-Rayet. Dubbed WR 136, this colossal star is unleashing a powerful stellar wind of charged particles from its surface, which is tearing apart the shell of surrounding material that the star blew off 250,000 years ago.
WR 136 created this web of luminous material during the late stages of its life. As a bloated, red supergiant, WR 136 puffed away some of its bulk, which then settled around it in a vast, roughly spherical cloud. When the star evolved from a supergiant to a Wolf-Rayet star, it developed an even fiercer stellar wind and began expelling mass at a furious rate. The stellar wind collided with the material around the star and swept it up into a thin shell. That shell broke apart into the network of bright clumps seen in the Hubble image.
Hubble’s close-up of the nebula reveals with unprecedented clarity that the shell of matter is a network of filaments and dense knots, all enshrouded in a thin “skin” of gas (seen in blue). Hubble’s sharp vision allows scientists to probe the intricate details of the complex system. Such details are crucial to understanding the life cycle of stars and their impact on the evolution of our galaxy. The observations were taken in June 1995 with Hubble’s Wide Field and Planetary Camera 2. Scientists selected the image’s colors to correspond with the ionization state of the gases (how many atoms have been lost or gained in the atoms of each gas), with blue representing the highest and red the lowest observed ionization.
Also cataloged as NGC 6888, Caldwell 27 was discovered by William Herschel in 1792. This stellar demolition zone lies within our own galaxy, about 4,700 light-years from Earth in the constellation Cygnus, the Swan. For best viewing, observe Caldwell 27 with a moderate to large telescope equipped with a light-pollution filter during the late summer from the Northern Hemisphere (or during the winter in the Southern Hemisphere). With a magnitude of 8.8, the Crescent Nebula is not visible to the naked eye — but if it were, it would appear in the sky as an ellipse one-quarter the size of the full moon. In the future, the nebula’s shell may become compressed and begin glowing again, this time as a powerful blast wave moves outward from the Wolf-Rayet star when it completely destroys itself in a supernova explosion.
Credit: Brian D. Moore and J. Jeff Hester (Arizona State University)
For more information about Hubble’s observations of Caldwell 27, see:
hubblesite.org/contents/news-releases/2000/news-2000-23.html
For Hubble's Caldwell catalog website and information on how to find these objects in the night sky, visit:
Skywatcher Evostar 72ED, Star Adventurer 2i, MGEN III, Nikon D5300a, Optolong L-Extreme
57x300s @ ISO 1600, edited in PixInsight, Affinity Photo
Believe it or not we got a clear night down here a couple of days ago. Just two hours before the clouds rolled in again at 2am, but enough time to do 40 x 2 minute subs on this thing. First widefield of the season :) A little overcooked but I'll give it more time if the clouds ever go away. Nice to see the Crescent - more by chance than design :)
As always in this region - too many blasted stars! ;)
Nikon D70 modded, 55-200 Nikkor at 200mm (cropped) , f5.6, 1600iso, Baader Neodymium filter.
40x120sec subs for a total of 1hr 20mins, unguided EQ5
Darks, flats and bias
Stacked and processed in DSS and CS5
Autosave006
I've just gotten back in the warm to process this image.
It's 9 x 10 minutes of the Crescent Nebula taken during a clear (but humid and dewy) night during the recent "Indian Summer" heatwave that we've been experiencing here in England this week! I didn't want to lose the opportunity to image this target.
The image looks better on a darker monitor, which subdues the effect of having so many stars in the picture!
NGC6888, Caldwell 27. Taken between 25th and 28th August 2021 in HOO.
The Crescent Nebula gets its shape as a result of an ageing star losing mass extremely quickly. Such a star is called a Wolf Rayet star and this one which is at the centre of the nebula will probably go supernova. According to the Sky at Night magazine this violent and rapid ejection has produced a dense shell of scorching hot material that gives the nebula its shape, while the complex structures seen within the bubble are likely the result of stellar winds colliding and interacting with older material ejected by the star long ago.
H: - 85 x 180s (4.25 Hours)
O: - 85 x 180s (4.25 Hours)
Total Integration = 9 hours.
Flats taken with a PURElite CFPL22 Ultra-Thin LED Light Box. Darks and Dark Flats taken afterwards and kept for future.
Telescope: - Skywatcher 130PDS Newtonian. Flocked with the shiny parts painted matt black. Additional camping mat protection from dew. Focuser upgraded with a ZWO EAF (Electronic Auto Focuser)
Camera : - ZWO ASI294MM with a ZWO 1.25” Electronic Filter Wheel
Filters:- Baader Mark-III MPCC Coma Corrector. Baader 7nm Ha and 8.5nm OIII narrowband.
Mount: - Skywatcher EQ6R.
Guiding: Skywatcher EvoGuide 50ED & ZWO ASI120MM-Mini.
Controlled by an ASIAir.
Processing Software: Stacked in Deep Sky Stacker and edited in Star Tools.
Moon: Pretty much full.
Light Pollution and Location: - Bortle 7/8 in Davyhulme, Manchester. Different websites tell me different things about this. It all depends on the time of night and which way I am pointing.
Weather: - High pressure but sitting horribly to the northwest of the country dragging lots of bitty cloud down from the north. Not ideal but dry enough to get a few days’ work in.
Notes: This is my first astrophotography project of the year having become a father at the start leaving me no time to do anything but be tired.
I wanted to go mono but to also make life easier and quicker, so I have invested in an auto focuser and the specialist astrophotography computer ASIAir. This has done the trick, polar alignment is extremely easy and then the rest can be automated so long as the focus is close. I like the way the Asiair automatically moves the mount into position when polar aligning, SharpCap relied on me rotating the mount which could have been inaccurate. It’s been a learning curve, especially getting the flats right but its quite intuitive and I think I am just about there.
Trying to get the colour somewhere near what I wanted it has been challenging too. I reprocessed this image several times.
During the off months I did spend time on upgrading my 130PDS to be very close to an astrograph. I flocked the inside, painted the shiny parts matt black, added more dew protection with camping mat material and covered the light leakage in the focuser with blue tac. I also used a laser collimator which I combined with my collimation cap to get the collimation right. One day I might add a fan to the primary mirror.
I got lots of hours in on this but would be tempted to reduce this in future to get more photos.
A relatively short exposure time of 2 hours 40 minutes of the Sadr Region and surrounding nebula.
Equipment used:
Canon 6D (stock)
70-200 2.8 IS II + 1.4 III
Sky Watcher Star Adventurer (unguided)
Astronomik 12nm Ha clip in
W&W Dew heater
-----
32 X 300" in Ha
10 dark frames
A single RGB frame added for stars
-----
Stacked in Deep Sky Stacker
Processed in Siril & Photoshop
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The Crescent Nebula (NGC 6888) is an emission nebula formed by a strong stellar wind from an extremely hot Wolf-Rayet star as it collides into and excites material that had been previously ejected from the star during it's red giant phase. Located approximately 5,000 light-years from Earth, the shell has a diameter of about 25 light-years in diameter.
Glowing at magnitude 7.4 in the constellation of Cygnus, although visible in smaller instruments, in large scopes under dark skies it appears as a fractured globe. Having had the pleasure of viewing this object in my friend's 20-inch, f/5 Obsession from the dark skies of the high desserts on the Snake River Plain in Idaho, it took on an incredible 3-D appearance (as one of my friends noted, looking like a partially constructed 'Death Star' from Star Wars :) ).
Image Details: The attached was taken by Jay Edwards at the HomCav Observatory on the evening of July 27, 2019 using an 8-inch, f/7 Criterion newtonian reflector and a Canon 700D DSLR tracked on a Losmandy G-11 mount running a Gemini 2 control system. This in turn was guided using PHD2 to control a ZWO ASI290MC planetary camera / auto-guider in an 80mm f/6 Celestron 'short-tube' refractor.
Shot at ISO 1600, it is a stack of 75 one-minute exposures (not including darks, flats & bias frames). Given the reasonable results I'm looking forward to trying this object sometime in the future using the same scope with one of our CCD and sets of narrowband filters in an attempt to pick up additional detail of the nebula's interior structure.
Stacked in DeepSkyStacker and processed using PixInsight and PaintShopPro, as presented here it has been cropped slightly, re-sized down to HD resolution and the bit depth has been lowered to 8 bits per channel.
The wide view. Lotsa stars here! Tonight's target, NGC 6888, the Crescent Nebula in Cygnus, lies in the plane of the Milky Way, where stars are most numerous. Integration time 108 minutes (9 x 12 min) through a 4nm hydrogen alpha (Hα) filter. If the weather permits me to get some exposures through other filters (oxygen III, in particular) I'll be able to combine them with this exposure for a color image.
Dark regions are areas where foreground dust has obscured more distant stars.
Starlight Xpress SX-36 CCD camera
Takahashi FSQ-106ED astrograph
Bisque MYT Mount
TheSkyX Professional
Pixinsight
Lightroom CC
Observatory control and image processing entirely on a Mac!
A short trip to the Southern French Alps gave wonderful views of the Milky Way.
I choose an ordinary 60mm lens (open at 2.2) in front of the STL 11km equipped with an Halpha filter. It took a mosaic of 3 shots to go from Deneb to to Altair.
Many famous nebulae can be seen here (see the notes and the large format): North America and the Pelican (top left); the Weil supernova remnant (left centre); the butterfly (top centre) and the crescent (centre).
15 subs of 10 minutes
This is one of my artworks based on an original astronomical photograph shot be me.
Image belongs to a large series of unpublished images called Visions.
More info in my blog: www.astroanarchy.blogspot.fi/2013/09/visions-of-space.html
Dragged out a few (old) SII frames...
Seemed the only color assignment that "went together" was OIII as green and SII as blue...(?)
So I went to town and applied some decon to it.
Maybe my eyes are failing...but I quite like it .
(Large central defect due to no SII flat....)
Subject: Widefield of Cygnus area -- NGC6888, NGC6960, NGC6974, NGC6979, NGC7000, IC1318, IC5067, IC5068, IC5070, etc. --
North America Nebula, Pelican Nebula, Crescent nebula, Veil nebula, etc.
Image FOV: roughly 22 degrees by 17 degrees (partial coverage)
Image Scale: roughly 40 arc-second/pixel
[See "Cygnus Widefield (56 panels) for other shooting data]
Gamma Cygni area widefield. EOS 500Da + EF 2,0/135mmL, Astronomik 12nm OIII, 12nm H-Alpha, 12nm SII.
67x3 min Ha @ f2/ISO 800
49x6 min OIII @ f2/ISO 800
40x6 min SII @ f2/ISO 800
Mapping R=SII, G=H-Alpha,B=OIII.
A narrowband image in natural colors palette using SII, Ha and OIII emission bands.
Integration time 5x10 minutes per channel.
Atik 460EX, Takahashi Sky 90
7 x Ha 300s 1x1 binned
4 x Red 240s 2x2 binned
3 x Green 300s 2x2 binned
3 x Blue 360s 2x2 binned
Flats
DSS, CS4 and LR3.
The crescent nebula in Cygnus is a popular and easy target for amateur telescopes. A powerful, yet dying star called a Wolf-Rayet star is responsible for this formation of glowing dust and gas, and will end its life as a supernova.
Takahashi Sky 90 at f/4.5
SBIG STL-4020M (self-guided)
Takahashi EM-200
Hutech LPS Filter
Ha: 5:20 (20 minute subexposures)
Luminance: 1:30 (5 minute subexposures)
RGB: 30 minutes each channel (5 minute subexposures)
Processed in Maxim/DL, ImagesPlus, Registar, and Photoshop
Noel Carboni's Astronomy Tools Actions
Had a lot of problems with star trail last night, hence I couldn't process as sharp as I'd like.
Think I need to tweak my mounts polar alignment.
Had to use the layered, Darken blend mode, Offset trick in PS to recover the image. Which slightly blurs the end result.
www.flemingastrophotography.com/startrails.html
C9.25 with f/6,3 FR on CGE mount.
Guided with PHD, processed in DSS and CS5.
8 x 300s 7nm Ha 1x1, reduced 50%
All sizes:- www.flickr.com/photos/mickhyde/14187023558/sizes/o/in/pho...
NGC6888 is an emission nebula in the constellation Cygnus, about 5000 light-years away.
With some extra processing to enhance the Crescent Nebula itself....so hopefully this one is a little more pleasing.
So even though your eye would not be able to see this, but for an extremely faint fuzzy ghost of a wisp of the brighter portion of the crescent on the egg, this particular image was processed from 30 x 180" (90 minutes integrated) in RGGB color. Together with another 180 calibration frames).
STEREO IMAGE:
astroanarchy.blogspot.com/2009/03/butterfly-nebula-as-ste...
Imaging data: - Camera, QHY8 - Filters, Baader 7nm H-alpha and Baader 8,5nm O-III - Optics, Tokina AT-X 300mm @ f2.8
- Exposures, 5 X 1200s H-alpha 3 X 1200s O-III
4 X 1200s S-II + flats and bias
- Guiding, LX200 GPS 12" + PHD-guiding and Lodestar
LARGE IMAGE:
1.bp.blogspot.com/_9HcYqbvUc4s/SPHOgy_eUnI/AAAAAAAABVg/eP...
G(H-a)B(O-III)+ISO.jpg){kind=link}
Details:
- 2016.08.05 / Valea Frumoasei, Romania
- Canon 750D + ED80; EQ3.2 mount
- 10 x 2min, darks, bias and flats
Cygnus is a familiar summer constellation. Situated along the plane of our Milky Way galaxy, it is home to many emission nebula, dark nebula and supernova remnants. To the lower left are the North American and Pelican Nebulae. The lower right shows the supernova remnant known as the Veil Nebula. The bimodal nebula at the middle left is the Butterfly Nebula. Smaller nebulae such as the Crescent and Tulip Nebulae are also visible in this image. Link to H-alpha only version here
Technical details:
Polar alignment wasn't great, so some amount of field rotation is visible. Overall though, I'm pleased with the result.
Imaging scope: Nikon 55mm f/1.8 Lens set to f/4
Imaging Camera: ST8300M (capture with Equinox Image)
Filters: Baader filters in FW5-8300 filter wheel
Guide scope: Astro-Tech 106mm Triplet
Guide camera: Starfish Fishcamp (guided with PHD)
Mount: Atlas EQ-GCalibration and processing in PixInsight.
Synthetic luminance from all frames
LHaRGB:
L: 20x1min (1x1)
Ha: 16x5min + 6x3min (1x1)
R: 10x1min (1x1)
G: 10x1min (1x1)
B: 10x1min (1x1)
Cepheus Flare Complex is in the left upper quarter of the frame. We can see green trace of drifting comet C/2014 E2 Jacques near the left edge.
equipment: Sigma 35mmF1.4 DG HSM "Art" and Canon EOS 5Dmk2-sp2, modified by Seo-san on Takahashi EM-200 Temma 2 Jr, autoguided with Takahashi FSQ-106ED, hiro-design off-axis guider, SX Lodestar, and PHD Guiding
exposure: 6 times x 30 minutes, 5 x 15 min, 4 x 4 min, and 6 x 1 minute at ISO 1,600 and f/4.0
site: 11,000 feet above sea level near Mauna Loa Observatory in Hawaii
One of my artworks based on an original astronomical photograph shot by me.
Image belongs to a large series of unpublished images called Visions.
Note. Image is manipulated but all the elements in it are from a real astronomical object. Moreinfo in my Blog: www.astroanarchy.blogspot.fi/2013/10/visions-of-space-xii...
This is just a portion of a huge nebulous region near the bright star Sadr in the constellation of Cygnus. Sadr is the bright star near the center of this image. This image contains many objects, each with their own designation. Among the brightest are IC 1318 (The Butterfly Nebula), IC 1311, and NGC 6888 (The Crescent Nebula). This image is a mosaic of 12 frames, covering approximately 6.2° x 5.5° of sky.
Takahashi Sky 90 at f/4.5
SBIG STL-4020M (self-guided)
Takahashi EM-200
Hutech LPS Filter
Mosaic of 12 frames
Ha: 36 hours total for all frames (20 minute subexposures)
Processed in Maxim/DL and Photoshop
Noel Carboni's Astronomy Tools Actions
Gamma Cygni area widefield. EOS 500Da + EF 2,0/135mmL, Astronomik 12nm OIII + 12nm H-Alpha. 67x3 min Ha @ f2/ISO 800 + 36x6 min OIII @ f2/ISO 800. Mapping R=Ha, G,B=OIII
Subject: NGC6888 - Crescent Nebula
Image FOV: 1.6 degree by 1.066 degrees (96 by 64 minutes)
Image Scale: 4 arc-second/pixel
Date: 2009/05/31
Exposure: 3 x 10m = 30 minutes total exposure, ISO800, f/5.6
Filter: IDAS LP
Camera: Hutech-modified Canon 30D
Lens: Nikon 800mm f/5.6 AIS
Mount: Astro-Physics AP900
Guiding: ST-402 autoguider through SV66 guidescope, Maxim DL autoguiding software with 6-second guide exposures
Processing: Raw conversion and calibration with ImagesPlus (dark and bias frames only, no flat frames); Aligning and combining with Registar. Final processing (levels adjustment, cropping, resizing, JPEG conversdion, etc.) in Photoshop.
Remarks: Temperature = 35F; SQM-L reading: 21.46 (moon had set) -- Imaging cut short after just 30 minutes, due to clouds
La constellation du Cygne à 45mm (équivalent à 67mm en 24x36): 8 images... Sur 20 produites, mais 12 ont dû être rejetées pour cause de formation de buée DANS l'objectif: celui ci n'est pas étanche, à cause du mécanisme de bascule et décentrement... La prochaine fois, je l'emballerai dans un sac plastique. Autre problème: la mise au point glisse, à cause du poids de la lentille frontale: il faut prévoir un dispositif de blocage. 3 Darks, 10 Offsets ; 15 Flats. Assemblage dans IRIS et cosmétique dans Photoshop CS4. Nikon D5300 modifié astro par Eos for Astro, Nikkor PC-E 45mm F/2.8, télécommande Twin1 ISR2 + Monture Astrotrac 320x+ filtre IDAS LPS-D1-N
Paramètres: 240s F/3.2 ISO 800, 45mm.
Série prise le 28.7.2017
Photo sans légende: www.flickr.com/photos/achrntatrps/36263581215/in/photostr...
15x180s, dark, bias, flat
Canon 7D modded - Astrodon Inside
ISO 800
Lens : SkyWatcher StarTravel 102 f4.9 Achromatic Refractor (500mm)
Astronomik Ha filter 12nm
AstroTrac unguided
Stacked in DSS, post-processed in Photoshop
Uncropped image
Original color maintained
First try with this achromatic scope, which is probably one of the lowest-end ever.
Star trails due to heavy scope on AstroTrac
NGC 6888 Crescent Nebula
ES 102ED APO, EQ5 Pro
ZWO ASI071, Orion MMAG, L-Pro filter
2hrs exposures
10-12-21
Bexley Kent
25min total (5x300s@800iso)
UK 31/12/13
Takahashi FSQ106ED f/5
Celestron Advanced Vx Mount Guided
Canon D1100 (modified) CLS filter
BackyardEOS, PHD
Deepskystacker, Photoshop CS6
I finally got around to processing this shot of the Crescent Nebula. The data was taken on the 1st and 16th of June 2017 and left on my hard drive. It's a tricky object to image from London without narrowband filters but at least on this attempt I managed to bring out more than just some of the outline.
[Wikipedia]The Crescent Nebula (also known as NGC 6888, Caldwell 27, Sharpless 105) is an emission nebula in the constellation Cygnus, about 5000 light-years away from Earth. It was discovered by Friedrich Wilhelm Herschel in 1792. 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. The result of the collision is a shell and two shock waves, one moving outward and one moving inward. The inward moving shock wave heats the stellar wind to X-ray-emitting temperatures.
It is a rather faint object located about 2 degrees SW of Sadr. For most telescopes it requires a UHC or OIII filter to see. Under favorable circumstances a telescope as small as 8 cm (with filter) can see its nebulosity. Larger telescopes (20 cm or more) reveal the crescent or a Euro sign shape which makes some to call it the "Euro sign nebula". [en.wikipedia.org/wiki/Crescent_Nebula]
106 x 75 second exposures at 400 ISO (two hours, 12 and a half minutes integration time).
32 x dark frames
105 x flat frames
21 x bias/offset frames (subtracted from flat frames only)
Captured with APT
Guided with PHD2
Processed in Nebulosity and Photoshop
Equipment:
Sky-Watcher Explorer-150PDS
Skywatcher EQ5 Mount
Orion 50mm Mini Guide Scope
ZWO ASI120 MC imaging and guiding camera
Canon 700D DSLR
NGC6888 - The Crescent Nebula in Ha and OIII. I'm glad I got the outer OIII shell, although it is pretty noisy.
Imaging scope: Orion EON 80ED
Imaging Camera: ST8300M (capture with Equinox Image)
Filters: Baader Narrowband filters in FW5-8300 filter wheel
Guide scope: AT8RC
Guide camera: Starfish Fishcamp (guided with PHD)
Mount: Atlas EQ-G
Calibration in Equinox Image and processing in PixInsight.
R - Halpha: 6x5min (1x1)
G - OIII: 6x5min (2x2)
B - OIII: 6x5min (2x2)