Astrophotography
Astrophotography
Welcome to the astro-imaging album of the Anne H Cruickshank Observatory (ACO) at the 51cg. Every picture here was taken with the John Cruickshank Telescope (JCT), a 16-inch reflecting telescope, and was made by ACO AI, the observatory's artificial-intelligence operator. Using autonomous navigation, it steered the telescope to each target, checked its aim by matching the stars in the image against a star map, and took the exposures itself.
Faint objects such as glowing gas clouds are far too dim to show up in one short exposure. So ACO AI takes several and stacks them, adding them together to bring out fine detail and reduce the graininess. The camera is black-and-white to capture more light, so colour comes from taking separate exposures through coloured filters and combining them.
Several styles of colour picture appear in the album. Narrowband images use filters that pass only the light from particular glowing gases: hydrogen, oxygen and sulphur. In the Hubble palette (SHO) each gas is given its own colour, a false-colour view of where each one sits in the cloud. Astronomers have used this technique on many of the Hubble Space Telescope's best-known pictures. In the Natural palette the gases are shown closer to the colours they really glow, with hydrogen red and oxygen blue-green.
Galaxies and star fields are more often shown as LRGB composites: red, green and blue (RGB) Bessel broadband filters capture true colour - cool orange stars, hot blue stars, the warm core and cooler outer disc of a galaxy - while a separate, sharper set of unfiltered exposures supplies the luminance (L): the fine brightness detail and structure. The two are then fused, colour from the RGB data and detail from the L data, giving a picture that is both naturally coloured and crisply resolved.
For a few targets the two approaches are blended together into a hybrid composite: an LRGB image with a touch of narrowband data (usually hydrogen-alpha) mixed in to bring out a feature broadband colour alone can't show, such as a galaxy's star-forming outflow. Images captured without filters stand on their own too, shown in monochrome. Each image has a caption saying what it shows, roughly how far away the target is and imaging details.
The Andromeda Galaxy, M31, is the nearest large galaxy to our own Milky Way, about 2.5 million light-years away in the constellation Andromeda. The whole galaxy spans about three degrees of sky, six times the width of the full Moon, so this image is a close-up of just its heart: the bright, crowded central bulge. The bulge glows a warm yellow because it is made mostly of old, cool stars, billions of years older than the young blue stars that light up the spiral arms further out. On the right, dark dust lanes in the galaxy's disc sweep past the bulge and stand out in silhouette against the light behind them. The scattered points of light are foreground stars in our own Galaxy, much closer to us than M31 itself. North is up and East is left.
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Imaged overnight on 21-22 September 2026 with the John Cruickshank Telescope (GSO 16-inch Ritchey-Chretien) at the Anne H Cruickshank Observatory, 51cg (57.17 N, 2.10 W), on a tracking equatorial mount (EQ8-R Pro). Zeus 455M PRO monochrome camera, 2x2 binned, gain 100, cooled to about -20 C. The target was centred by plate-solving and refocused during the night, between short imaging rounds that alternated with the nearby companion galaxy M32.
- Field and scale: the image shown is 1920 x 1263 pixels, resized down for web display from the full 4588 x 3018 pixel stack (camera native scale about 0.48 arcseconds per pixel), covering about 36.7 x 24.1 arcminutes - a little more than the width of the full Moon.
- The data: luminance (no filter) 16 x 45 s, and red, green and blue filters 8 x 45 s each, 30 minutes of exposure in total. Frames dimmed by passing cloud were left out.
- Colour: the red, green and blue frames give the colour; the luminance frames give the brightness and detail. Colours were balanced on the field's own stars, with a neutral sky background.
- Processing: each frame was plate-solved and aligned to a fraction of a pixel, corrected for a patch of dew that formed on the optics during the night (see below), and combined with outlier rejection. The result was given a gentle brightness stretch to show the faint outer glow without losing the bright core, then brightened in the midtones and given richer colour, with the colour smoothed slightly first so the boost does not raise colour noise. The haze over the whole image was then cleared, the contrast lifted in the midtones and the dust lanes and the shape of the bulge brought out with gentle local contrast, while the bright core was kept from burning out. It was then resized and lightly sharpened for the web.
- Dew: during imaging, dew formed on the telescope optics and dimmed an oval patch in the middle of the camera's view, by up to about a quarter by dawn. Its shape and strength were measured from the frames themselves and divided out, frame by frame, and its remaining traces around the core were evened out to match the surrounding light.
- Capture times (BST), real timestamps from the saved subframes (each saved at the end of its 45 s exposure), first to last frame used:
- Luminance: 23:39:11 to 03:19:31 (16 subframes, in four rounds)
- Red: 23:42:51 to 03:21:31 (8 subframes)
- Green: 23:44:39 to 03:23:16 (8 subframes)
- Blue: 23:46:26 to 03:24:59 (8 subframes)
NGC 7331 (Caldwell 30) is a spiral galaxy in the constellation Pegasus, about 40 million light-years away. In size and structure it is often compared to our own Milky Way, so this is roughly how our Galaxy might look to an observer far away. We see its disc steeply tilted: the warm yellow glow at the centre is the bulge of old stars, and around it the spiral arms trace a fainter, bluer oval of younger stars, crossed by dark lanes of dust on the near side. The small smudges scattered around it are other galaxies, most of them far more distant than NGC 7331 itself, and every sharp point of light is a star in our own Galaxy, much closer to us. North is up and East is left.
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Imaged overnight on 21-22 September 2026 with the John Cruickshank Telescope (GSO 16-inch Ritchey-Chretien) at the Anne H Cruickshank Observatory, 51cg (57.17 N, 2.10 W), on a tracking equatorial mount (EQ8-R Pro). Zeus 455M PRO monochrome camera, 2x2 binned, gain 100, cooled to about -20 C. The target was centred by plate-solving, in short imaging rounds through the night.
- Field and scale: the image shown is 1600 x 1600 pixels at the camera's full binned resolution, about 0.48 arcseconds per pixel, covering about 12.8 x 12.8 arcminutes around the galaxy. It is cropped, without resizing, from the full stack (4560 x 2954 pixels, about 36 x 24 arcminutes).
- The data: luminance (no filter) 35 x 45 s, red 20 x 45 s, green 21 x 45 s and blue 20 x 45 s, 72 minutes of exposure in total. Frames dimmed by cloud or a bright sky were left out.
- Colour: the red, green and blue frames give the colour and the luminance frames the brightness and detail. Colours were balanced on the field's own stars, with a neutral sky background.
- Processing: each frame was plate-solved, corrected for a patch of dew that formed on the optics during the night (see below), aligned to a fraction of a pixel and combined with outlier rejection. The result was given a gentle brightness stretch to show the faint outer arms without losing the bright core, and lightly sharpened for the web.
- Dew: during the night, dew on the telescope optics dimmed an oval patch in the middle of the camera's view, with a slightly brighter ring of scattered light around it. Its effect was measured from the sky around the galaxy in every frame and divided out. Frames with the heaviest dew counted for less in the final stack. Two faint dark bands it left across the galaxy's level, beside the core and below it, were then evened out from the surrounding sky.
- Capture times (BST), real timestamps from the saved subframes (each saved at the end of its 45 s exposure), first to last frame used:
- Luminance: 21:46:15 to 02:26:12 (35 subframes)
- Red: 21:40:35 to 02:28:10 (20 subframes)
- Green: 21:42:20 to 02:29:53 (21 subframes)
- Blue: 21:44:05 to 02:31:35 (20 subframes)
M81, also known as Bode's Galaxy, is a grand-design spiral galaxy in the constellation Ursa Major, about 12 million light-years away. It is one of the most striking and well-studied spirals in the sky, prized for its tightly wound, clearly defined arms winding out from a bright central bulge. In this vivid image the bulge glows a warm gold-orange, the light of its many older, cooler stars, while the disc and spiral arms further out take on a blue tint, where younger, hotter stars are forming. M81 anchors the M81 Group, a family of dozens of galaxies that includes its smaller, chaotic neighbour M82 (the Cigar Galaxy, imaged at this observatory two nights earlier). A close gravitational encounter between the two, tens of millions of years ago, is thought to have triggered M82's intense burst of star formation while leaving M81's own spiral structure largely intact. The colours are strengthened for presentation. North is up and East is left.
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Imaged overnight on 18-19 October 2026 with the John Cruickshank Telescope (GSO 16-inch Ritchey-Chretien) at the Anne H Cruickshank Observatory, 51cg (57.17 N, 2.10 W), on a tracking equatorial mount (EQ8-R Pro). Zeus 455M PRO camera, gain 300, cooled to about -16 to -20 C. The galaxy was centred by plate-solving and the focus set from a same-night focus sweep.
- Field and scale: the image shown is 1500 x 1500 pixels at about 1.0 arcseconds per pixel, covering about 25 x 25 arcminutes centred on the galaxy. It is cut from the full-resolution composite (about 0.24 arcseconds per pixel, no binning) and reduced in size.
- Data: luminance (L) 16 x 60 s, and red, green and blue 6 x 90 s each (5 used for green), about 42 minutes in total.
- Luminance: the 16 L frames were each plate-solved, aligned and median-stacked, then stretched to bring out the faint outer spiral without blowing out the bright core.
- Colour: the red, green and blue frames were each plate-solved and aligned onto the luminance, background-equalised and median-stacked, then combined with the luminance, which supplies all the brightness and detail. For this version the core was warmed towards gold-orange, the outer disc and arms pushed towards blue, the colours strengthened, the large-scale contrast of the arms increased and the sky background darkened; the stars keep their own colours.
- Capture times (BST), by filter, real timestamps from the saved subframes:
- L: 22:54:30 to 23:59:29 (16 subframes, 60 s each)
- R: 23:15:16 to 23:44:43 (6 subframes, 90 s each)
- G: 23:20:59 to 23:50:31 (6 subframes, 90 s each; 5 used)
- B: 23:26:40 to 23:56:20 (6 subframes, 90 s each)
M82, nicknamed the Cigar Galaxy for its edge-on, elongated shape, sits in the constellation Ursa Major about 12 million light-years away. It's the closest well-known example of a starburst galaxy - one undergoing an exceptionally intense burst of star formation, here triggered by a close gravitational encounter with its much larger neighbour M81. That interaction compressed M82's gas and set off star formation at a rate many times faster than a typical spiral galaxy, visible here as the mottled, knotty glow running along its disk. The same burst of star formation drives a powerful galactic-scale outflow - gas blown out of the disk by stellar winds and supernovae, glowing in hydrogen-alpha light and picked out here in red-orange, extending above and below the visible disk. M82's disturbed, irregular structure is itself a direct result of its ongoing gravitational tug-of-war with M81. North is up and East is left.
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Imaged overnight on 15-16 October 2026 (about 01:00 to 05:08 BST) with the John Cruickshank Telescope (GSO 16-inch Ritchey-Chretien) at the Anne H Cruickshank Observatory, 51cg (57.17 N, 2.10 W), on a tracking equatorial mount (EQ8-R Pro), in an unattended overnight session. Zeus 455M PRO camera, cooler at 0 C.
- Field and scale: the image shown is 1280 x 977 pixels, about 18.2 x 13.9 arcminutes at about 0.85 arcseconds per pixel, cropped around the galaxy from the full frame (about 0.24 arcseconds per pixel, no binning) and reduced in size.
- Data: luminance (L) 32 subframes, red 13, green 14, blue 14 and hydrogen-alpha (Ha) 21.
- Processing: the subframes for each filter were aligned and median-stacked, which removes hot pixels, cosmic-ray hits and satellite trails; a soft stretch with no hard ceiling keeps the gradient in the bright core; then light brightening and sharpening.
- Colour: red, green and blue broadband colour, with the hydrogen-alpha data (cleaned of stars and of its background gradient) added strongly to red and slightly to green, so the outflow lobes stand out.
- Star field: nine bright stars outside the galaxy were removed and the gaps filled with matching sky grain.
- Capture times (BST), by filter, real timestamps from the saved subframes:
- L: 01:05:16 to 04:58:13 (32 subframes)
- Ha: 01:16:45 to 05:08:07 (24 subframes captured, 21 used after registration)
- R: 01:25:59 to 04:45:12 (14 subframes captured, 13 used after registration)
- G: 01:31:01 to 04:48:51 (14 subframes)
- B: 01:34:38 to 04:52:19 (14 subframes)
- (SII and OIII were also captured but are not used in this colour blend)
NGC 891 (Caldwell 23) is a spiral galaxy in the constellation Andromeda, about 30 million light-years away, which we happen to see exactly edge-on. Its disc appears as a thin sliver of light, split along its length by a dark lane of dust and gas silhouetted against the starlight behind it, with the warm golden glow of the central bulge of older stars swelling out on either side. This is very much how our own Milky Way would look from far outside its plane - the band of the Milky Way across our night sky has the same dark dust lane running down its middle - which is why NGC 891 is often used as a stand-in for our Galaxy seen side-on. The points of light around it are stars in our own Galaxy, much closer to us. North is up and East is left.
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Imaged in the early morning of 22 September 2026 with the John Cruickshank Telescope (GSO 16-inch Ritchey-Chretien) at the Anne H Cruickshank Observatory, 51cg (57.17 N, 2.10 W), on a tracking equatorial mount (EQ8-R Pro). Zeus 455M PRO monochrome camera, 2x2 binned, gain 100, cooled to about -20 C. The target was centred by plate-solving.
- Field and scale: the image shown is 1600 x 1600 pixels, covering about 20 x 20 arcminutes around the galaxy at about 0.75 arcseconds per pixel. It is a 2500 x 2500 pixel crop of the full stack (4628 x 3026 pixels, about 37 x 24 arcminutes, at the camera's binned scale of about 0.48 arcseconds per pixel), reduced in size for the web.
- The data: luminance (no filter) 20 x 45 s, and red, green and blue 10 x 45 s each, 37.5 minutes of exposure in total. Every frame was used.
- Colour: the red, green and blue frames give the colour and the luminance frames the brightness and detail. Colours were balanced on the field's own stars, with a neutral sky background. The galaxy's colour and brightness were then enhanced for presentation (see Processing).
- Processing: each frame was plate-solved, corrected for a patch of dew that formed on the optics during the night (see below), aligned to a fraction of a pixel and combined with outlier rejection, then given a gentle brightness stretch. The galaxy alone - not the sky or the stars - was then brightened, given richer colour, lightly smoothed to reduce grain while keeping the dust lane sharp, and its core toned from bright yellow to a warmer gold. The image was then resized and lightly sharpened for the web.
- Dew: this target was imaged at the end of the night, when dew on the telescope optics was heaviest; it dimmed an oval patch in the middle of the camera's view, with a slightly brighter ring of scattered light around it. Its effect was measured from the sky around the galaxy in every frame and divided out, and the faint traces it left around the galaxy were smoothed into the surrounding sky.
- Capture times (BST), real timestamps from the saved subframes (each saved at the end of its 45 s exposure):
- Luminance: 03:43:52 to 04:23:56 (20 subframes)
- Red: 03:47:35 to 04:25:56 (10 subframes)
- Green: 03:49:20 to 04:27:42 (10 subframes)
- Blue: 03:51:04 to 04:29:25 (10 subframes)
The Triangulum Galaxy (M33), a face-on spiral in the constellation Triangulum, about 2.73 million light-years away, and the third-largest member of our Local Group after the Milky Way and Andromeda. At roughly half the Milky Way's diameter, it's a genuine spiral in its own right rather than a satellite of its larger neighbour Andromeda, though the two may have interacted in the past. Its loose, patchy arms are threaded with pink star-forming knots, picked out here by blending in narrowband hydrogen-alpha, oxygen-III and sulfur-II data on top of the natural broadband colour - the brightest of these, NGC 604, is one of the largest known star-forming regions in the Local Group, far bigger than the Orion Nebula, and is the bright knot visible in the upper-left of the disk here. Under a dark enough sky M33 is one of the most distant objects visible to the naked eye, though its light is spread thin enough across the sky that it can actually be harder to pick out than the more compact, brighter-looking Andromeda Galaxy. A warm glow marks the compact nucleus at the galaxy's centre, giving way to a cooler, blue-tinted outer disc further out along the spiral arms. North is up and East is left.
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Imaged overnight on 13-14 October 2026 (about 21:03 to 04:07 BST) with the John Cruickshank Telescope (GSO 16-inch Ritchey-Chretien) at the Anne H Cruickshank Observatory, 51cg (57.17 N, 2.10 W), on a tracking equatorial mount (EQ8-R Pro), in an unattended overnight session. Zeus 455M PRO camera, cooled to -20 C. The mount made a meridian flip during the night, so frames from either side of it are turned 180 degrees relative to each other; every frame was aligned by its own plate solution.
- Field and scale: the image shown is 1200 x 1064 pixels at about 1.44 arcseconds per pixel, covering about 29 x 26 arcminutes centred on the galaxy, cut from the processed image of the camera's full field (38 x 26 arcminutes, recorded at about 0.24 arcseconds per pixel, no binning, and reduced in size during processing).
- Data: 225 subframes - luminance (L) 47, red 24, green 24, blue 22, and 36 each through hydrogen-alpha (Ha), oxygen-III (OIII) and sulfur-II (SII) narrowband filters.
- Colour: brightness and structure come from the luminance stack, colour from the red, green and blue data blended with the narrowband data, which picks out the star-forming regions; red was reduced slightly to tone down a warm cast.
- Processing: every subframe was plate-solved and aligned by its own solution (rotation, scale and position), and the frames for each filter were median-stacked; the background was removed; the image was stretched with denoising, sharpened at three scales to bring out the spiral arms, and given a tone curve that darkens the faint haze around the galaxy while lifting the arms and core. A warm glow was added around the nucleus and a blue tint to the outer disc, both kept off the stars and the background.
- Capture times (BST), by filter, real timestamps from the saved subframes - each filter ran as a recurring slot across the whole night rather than in one continuous block:
- L: 21:06:49 to 03:45:20 (48 subframes captured, spans the meridian flip; 47 used)
- SII: 21:13:52 to 04:07 (36 subframes)
- Ha: 21:18:33 to 04:07 (36 subframes)
- OIII: 21:23:14 to 04:07 (36 subframes)
- R: 21:28:00 to 04:07 (24 subframes)
- G: 21:31:45 to 04:07 (24 subframes)
- B: 21:35:24 to 04:07 (22 subframes)
NGC 6946, nicknamed the Fireworks Galaxy, lies on the border of the constellations Cepheus and Cygnus, about 25 million light-years away, and we see it almost face-on, showing off its loose, patchy spiral arms. It earned its nickname by hosting ten observed supernovae since 1917 - more than any other known galaxy - and its arms are still rich in young stars and star-forming regions, seen here as blue and pink knots of light wound around a warm, golden centre of older stars. The galaxy lies behind the dusty plane of our own Milky Way, which dims and reddens its light. The points of light around it are stars in our own Galaxy, much closer to us. The colours are strengthened for presentation. North is up and East is left.
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Imaged on the evening of 23 September 2026 with the John Cruickshank Telescope (GSO 16-inch Ritchey-Chretien) at the Anne H Cruickshank Observatory, 51cg (57.17 N, 2.10 W), on a tracking equatorial mount (EQ8-R Pro). Zeus 455M PRO monochrome camera at full resolution, gain 100, cooled to -20 C.
- Field and scale: the image shown is 1200 x 939 pixels at about 0.90 arcseconds per pixel, covering about 18 x 14 arcminutes centred on the galaxy. It is cropped from the full processed image (5411 x 3521 pixels, 0.24 arcseconds per pixel, about 22 x 14 arcminutes) and reduced in size.
- Data: 45 s exposures - luminance (no filter) 18, red 8, green 7 and blue 6 - about 29 minutes in total. Later in the night dew formed on the optics; those frames were left out.
- Luminance: every frame was plate-solved and aligned by its star positions, weighted by sky clarity and sharpness, and combined with outliers (satellite trails, hot pixels) rejected. The uneven sky background was modelled and removed (more strongly towards the edges of the field, where the darkening of the corners is greatest), the noise reduced at fine scales while keeping the detail in the arms, and the result stretched to show the faint outer arms.
- Colour: the red, green and blue frames were aligned and combined the same way, balanced so that the average field star is white, and combined with the luminance, which supplies the brightness and detail. The colours were then strengthened and the galaxy brightened; the colours of the field stars were toned down so that they look nearly white. Finally the strongest blues were toned down a little and the image sharpened slightly, the stars most, the galaxy gently and the empty sky not at all. The image was cropped, reduced in size and lightly sharpened.
- Capture times (GMT), by filter, real timestamps from the saved subframes:
- L: 20:40:36 to 21:36:11 (18 subframes used, 45 s each)
- R: 20:46:25 to 21:27:40 (8 used, 45 s each)
- G: 20:48:49 to 21:30:02 (7 used, 45 s each)
- B: 21:02:40 to 21:32:22 (6 used, 45 s each)
M32 is a small elliptical galaxy in the constellation Andromeda, a close companion of the great Andromeda Galaxy (M31) and, like it, about 2.5 million light-years away. Unlike its giant spiral neighbour, M32 has no spiral arms, dust lanes or star-forming regions: it is a smooth, densely packed ball of old stars, which is why it glows a soft, even gold, brightening steadily towards an intensely bright centre that is thought to hold a supermassive black hole. M32 is unusually compact for its brightness, and many astronomers think it is what remains of a once-larger galaxy whose outer stars were stripped away by Andromeda's gravity. The sharp points of light around it are stars in our own Galaxy, much closer to us. North is up and East is left.
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Imaged overnight on 21-22 September 2026 with the John Cruickshank Telescope (GSO 16-inch Ritchey-Chretien) at the Anne H Cruickshank Observatory, 51cg (57.17 N, 2.10 W), on a tracking equatorial mount (EQ8-R Pro). Zeus 455M PRO monochrome camera, 2x2 binned, gain 100, cooled to about -20 C. The target was centred by plate-solving, in short imaging rounds that alternated with the core of the neighbouring Andromeda Galaxy.
- Field and scale: the image shown is 1200 x 1200 pixels at the camera's full binned resolution, about 0.48 arcseconds per pixel, covering about 9.6 x 9.6 arcminutes centred on the galaxy. It is cropped, without resizing, from the full stack (4616 x 3034 pixels, about 37 x 24 arcminutes).
- The data: luminance (no filter) 13 x 45 s, red 8 x 45 s, green 8 x 45 s and blue 6 x 45 s, 26 minutes of exposure in total. Frames dimmed by haze or a bright sky were left out.
- Colour: the red, green and blue frames give the colour and the luminance frames the brightness and detail. Colours were balanced on the field's own stars, with a neutral sky background.
- Processing: each frame was plate-solved, corrected for a patch of dew that formed on the optics during the night (see below), aligned to a fraction of a pixel and combined with outlier rejection. The result was given a gentle brightness stretch to show the faint outer glow without losing the bright centre, and lightly sharpened for the web, with the background darkened slightly.
- Dew: during the night, dew on the telescope optics dimmed an oval patch in the middle of the camera's view, with a slightly brighter ring of scattered light around it. Its effect was measured from the sky around the galaxy in every frame and divided out, and the faint traces it left around the galaxy were smoothed into the surrounding sky.
- Capture times (BST), real timestamps from the saved subframes (each saved at the end of its 45 s exposure), first to last frame used:
- Luminance: 23:51:19 to 03:28:52 (13 subframes)
- Red: 23:52:33 to 03:30:53 (8 subframes)
- Green: 23:54:20 to 03:32:39 (8 subframes)
- Blue: 02:56:03 to 03:34:22 (6 subframes)
Messier 15 (NGC 7078) is a globular cluster in the constellation Pegasus, about 33,000 light-years away: a dense, roughly spherical swarm of several hundred thousand stars bound together by gravity, and among the oldest objects in our Galaxy, at around 12 billion years old. M15 is one of the most tightly packed globular clusters known - it has undergone what is called core collapse, in which its centre has contracted into an exceptionally dense core, seen here as the brilliant knot of light in the middle. The colours show the cluster's different kinds of stars: the golden and orange stars are red giants, old stars that have swollen and cooled near the end of their lives, while the blue-white stars, and much of the blue-white glow of the core, are hot stars that have already passed the red-giant stage. M15 is unusually rich in these hot stars because it is so old and so poor in heavy elements. It was discovered by Jean-Dominique Maraldi in 1746. North is up and East is left.
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Imaged on the evening of 30 September 2026 with the John Cruickshank Telescope (GSO 16-inch Ritchey-Chretien) at the Anne H Cruickshank Observatory, 51cg (57.17 N, 2.10 W), on a tracking equatorial mount (EQ8-R Pro). Zeus 455M PRO monochrome camera, cooled to about -20 C.
- Field and scale: the image shown is 1500 x 1500 pixels, covering about 24 x 24 arcminutes around the cluster at about 0.97 arcseconds per pixel. It is a square cut from the full height of the colour stack (about 0.48 arcseconds per pixel), with the left and right edges trimmed, reduced in size for the web.
- The data: luminance (no filter) 12 x 20 s, red 16 x 20 s, green 15 x 20 s and blue 14 x 20 s, 19 minutes of exposure in total.
- Colour: the red, green and blue frames give the colour and the luminance frames the brightness and detail. Colours were balanced on the field stars around the cluster (not on the cluster's own stars), with a neutral sky background, so the cluster's colours are shown as they are.
- Processing: the frames were calibrated with dark frames taken the same night, combined in pairs of pixels for a better signal, plate-solved, flattened for the telescope's slight darkening towards the corners, aligned to a fraction of a pixel and combined with outlier rejection. The result was given a gentle brightness stretch to show both the bright core and the faint outer stars, sharpened to tighten the stars, and resized and lightly sharpened for the web.
- Capture times (BST), real timestamps from the saved subframes, first to last frame used:
- Luminance: 23:00:58 to 23:51:09 (12 subframes)
- Red: 23:03:40 to 23:54:08 (16 subframes)
- Green: 23:05:59 to 23:56:25 (15 subframes)
- Blue: 23:08:18 to 23:58:31 (14 subframes)
M2 Globular Cluster
Messier 2 (NGC 7089) is a globular cluster in the constellation Aquarius, about 37,500 light-years away: a dense ball of around 150,000 stars bound together by gravity, roughly 175 light-years across, and one of the largest and oldest such clusters in our Galaxy, at around 13 billion years old. Its stars crowd ever more tightly towards the centre, until the core is too dense for individual stars to be told apart. The colours show the cluster's different kinds of stars: the golden and orange stars are red giants, old stars that have swollen and cooled near the end of their lives, while the blue-white stars, and much of the blue-white glow of the core, are hot stars that have already passed the red-giant stage. M2 was discovered by Jean-Dominique Maraldi in 1746. The scattered points of light around it are stars in our own Galaxy, much closer to us. North is up and East is left.
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Imaged in the early hours of 1 October 2026 with the John Cruickshank Telescope (GSO 16-inch Ritchey-Chretien) at the Anne H Cruickshank Observatory, 51cg (57.17 N, 2.10 W), on a tracking equatorial mount (EQ8-R Pro). Zeus 455M PRO monochrome camera at full resolution, cooled to about -20 C.
- Field and scale: the image shown is 1500 x 1500 pixels, covering about 20 x 20 arcminutes centred on the cluster at about 0.8 arcseconds per pixel. It is cut from the full-resolution stack (about 0.24 arcseconds per pixel) and reduced in size.
- The data: 20 s exposures - luminance (no filter) 8, red 12, green 12 and blue 12 - about 15 minutes in total.
- Dew: during the night dew formed on the telescope optics, dimming an oval patch in the middle of the camera's view. Its effect was measured from the sky in every frame and divided out, and the frames taken after it thickened were left out.
- Colour: the red, green and blue frames give the colour and the luminance frames the brightness and detail. Colours were balanced on the field stars around the cluster (not on the cluster's own stars), with a neutral sky background, so the cluster's colours are shown as they are.
- Processing: the frames were aligned to a fraction of a pixel and combined with outlier rejection, and the sky background was evened out. The luminance was sharpened by deconvolution, which tightens the star images blurred by the atmosphere, then given a strong brightness stretch to show both the dense core and the faint outer stars, with the background darkened. The image was turned to put north up, reduced in size and lightly sharpened for the web.
- Capture times (BST), real timestamps from the saved subframes, first to last frame used:
- Luminance: 00:20:14 to 00:53:47 (8 subframes)
- Red: 00:23:00 to 00:57:15 (12 subframes)
- Green: 00:25:20 to 00:59:34 (12 subframes)
- Blue: 00:27:36 to 01:01:44 (12 subframes)
NGC 7822 is a vast complex of glowing gas and dust in the constellation Cepheus, about 2,900 light-years away. In wide-field photographs the whole region traces a curling shape that has earned it the nickname "Question Mark Nebula"; this image zooms in on a small part of it, about half a degree across - roughly the width of the full Moon. Just left of centre is Berkeley 59, a young cluster of hot, massive stars only a few million years old. Their ultraviolet light makes the surrounding hydrogen glow red, while their radiation and winds sculpt the cloud into bright ridges, pillars and the dark lanes of dust that cut across it. The teal tones on the right come from oxygen, which glows where the gas is thinner and less dense with hydrogen. Regions like this are stellar nurseries: the same process that lit up Berkeley 59 may still be forming new stars inside the densest parts of the cloud. North is up and East is left.
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Imaged on the evening of 19 September 2026 with the John Cruickshank Telescope (GSO 16-inch Ritchey-Chretien) at the Anne H Cruickshank Observatory, 51cg (57.17 N, 2.10 W), on a tracking equatorial mount (EQ8-R Pro). Zeus 455M PRO camera, 2x2 binning, sensor cooled to about -20 C. The target was centred on the catalogue position of NGC 7822 by plate-solving.
- Field and scale: the image shown is 1250 x 915 pixels at about 1.56 arcseconds per pixel, covering a field of about 33 x 24 arcminutes, resized down for web display from the camera's full frame (about 0.48 arcseconds per pixel). It was plate-solved and rotated so that north is up and East is left; the thin black slivers in the bottom corners lie just outside the camera's field.
- Gas: narrowband exposures through hydrogen-alpha (Ha), doubly ionised oxygen (OIII) and ionised sulphur (SII) filters - Ha 5 x 90 s, OIII 5 x 90 s and SII 3 x 90 s at gain 300, 19.5 minutes in total - aligned by sub-pixel phase correlation and averaged. In this natural palette, Ha (with a little SII) is shown as red and OIII as teal, close to how the gas would look to the eye if it were bright enough to see in colour.
- Stars: colours taken from short broadband exposures (3 x 10 s each through Bessel R, G and B filters, gain 100) and applied to the stars that stand clearly above the noise, so the brighter stars show their true colours.
- Processing: moderate denoising; the black point set so the sky and dark dust lanes are near black; the brightness of the gas lifted with a smooth curve that keeps the gradients within the bright clouds and rolls the highlights off gently rather than clipping them, with the faint teal background darkened slightly so the red clouds stand out.
- A satellite (or other object) trail crosses the lower-left corner; it has been left in as captured.
- Capture times (BST), real timestamps from the saved subframes:
- Narrowband (Ha, OIII, SII): 22:54:15 to 23:15:15 (90 s subframes)
- Broadband stars (R, G, B): 23:15:37 to 23:18:05 (9 subframes, 10 s each)
The Pelican Nebula (IC 5070) is a cloud of glowing gas and dust in the constellation Cygnus, about 2,600 light-years away, next door in the sky to the larger North America Nebula. This frame looks into the "head and neck" of the pelican, where the gas is being lit and sculpted by young, hot stars nearby. The bright golden ridge curving through the centre is an ionisation front: a moving boundary where intense ultraviolet light strips electrons from the hydrogen, making it glow, and slowly eats into the cooler cloud beyond. The dark filaments and pillars along that edge are denser knots of gas and dust holding out against the radiation, and new stars may be forming inside some of them. The colours follow the "Hubble palette" made famous by the Hubble Space Telescope's "Pillars of Creation": sulphur and hydrogen emission show as gold, and oxygen emission as teal-blue, so the colours map where each element glows rather than what the eye would see. North is up and East is left.
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Imaged on the evening of 19 September 2026 with the John Cruickshank Telescope (GSO 16-inch Ritchey-Chretien) at the Anne H Cruickshank Observatory, 51cg (57.17 N, 2.10 W), on a tracking equatorial mount (EQ8-R Pro), unguided. Zeus 455M PRO monochrome camera, gain 300, cooled to about -20 C. The target was centred by ASTAP plate-solving (frame centre 0.8 arcminutes from the nebula's catalogued position), and focus was set with the ZWO electronic focuser at its documented star-focus position.
- Field and scale: the image shown is 1920 x 1181 pixels, resized down for web display from a 4461 x 2743 pixel north-up crop of the full-resolution composite (camera native scale about 0.48 arcseconds per pixel), covering a field of about 36 x 22 arcminutes - a little more than the width of the full Moon.
- The data: three narrowband filters, each isolating the light of one element - hydrogen-alpha (5 x 90 s), oxygen III (5 x 90 s) and sulphur II (3 x 90 s), 19.5 minutes of exposure in total.
- Colour: the "Hubble palette" - sulphur to red, hydrogen to green, oxygen to blue - with part of the green toned down, as is usual for this palette, which turns the hydrogen-rich front gold and the oxygen-rich gas teal.
- Processing: the frames for each filter were aligned and averaged, then combined into colour. The picture was turned to true north-up (checked by plate-solving), the edges trimmed, and the image given a deeper black, a gentle contrast curve, extra local contrast to bring out the dark pillars, a saturation boost that leaves bright stars white, and light colour-noise smoothing. It was then resized for the web and lightly sharpened.
- Capture times (BST), real timestamps from the saved subframes (start of first to start of last):
- Hydrogen-alpha: 21:00:05 to 21:06:27 (5 subframes, 90 s each)
- Oxygen III: 21:08:06 to 21:14:27 (5 subframes, 90 s each)
- Sulphur II: 21:16:06 to 21:19:17 (3 subframes, 90 s each)
The Elephant's Trunk Nebula (IC 1396A) in the constellation Cepheus, about 2,400 light-years away, is a long, dense cloud of cold gas and dust, shaped like an elephant's head and trunk, that is being eroded by the radiation and winds of hot, young stars in the surrounding region. Its dark body blocks the glowing gas behind it, while the rim along its head and the edges of the cloud shine where that radiation strikes them; new stars are forming inside dense clouds like this one. In this narrowband image the glowing gas appears teal, with bright gold-green rims along the edge of the trunk and around the cloud on the right, and the darker tones inside the trunk show its folds of dust. The colours are an artistic rendering of the narrowband data rather than a map of which gas glows where. North is up and East is left.
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Imaged on the evening of 18 September 2026 with the John Cruickshank Telescope (GSO 16-inch Ritchey-Chretien) at the Anne H Cruickshank Observatory, 51cg (57.17 N, 2.10 W), on a tracking equatorial mount (EQ8-R Pro). Zeus 455M PRO monochrome camera, 2x2 binned, gain 300, cooled to about -20 C.
- Field and scale: the image shown is 1600 x 1095 pixels, covering about 33 x 22 arcminutes at about 1.2 arcseconds per pixel. It is the full image (4545 x 2800 pixels at about 0.48 arcseconds per pixel) with the left-hand 10% trimmed off, reduced in size.
- The data: 90 s narrowband exposures - three showing the bright rim of the trunk (hydrogen-alpha) and two showing the trunk faintly without it - 7.5 minutes in total.
- Colour: a Hubble-style narrowband rendering, with the colours strengthened for presentation; stars are shown white.
- Processing: every frame was plate-solved and aligned to a fraction of a pixel, the frames for each filter were combined, the sky background was evened out and the noise was reduced, and the image was turned to north up. The large-scale brightness and colour were taken from an earlier rendering of the same night's data, which keeps the gradients inside the dark trunk, with the fine detail and the stars from the new stack; the gas was then brightened, its colours strengthened and the edges of the trunk lightly sharpened, and the result trimmed and resized for the web, with a final adjustment of the colour levels that slightly deepens the darkest tones and brightens the lighter ones.
- Capture times (BST), real timestamps from the saved frames: 21:18:22, 21:22:14, 21:24:47, 21:25:33 and 21:27:03.
The Pacman Nebula (NGC 281) is a large cloud of glowing gas in the constellation Cassiopeia, about 9,500 light-years away. It owes its nickname to the dark lanes of dust that cut in from the lower right, carving out a "mouth" that gives the cloud its Pac-Man shape. The nebula is lit from within by IC 1590, a young cluster of hot, massive stars, visible here as the tight knot of bright stars near the centre. Their ultraviolet light makes the surrounding gas glow, and their winds and radiation are slowly eroding the cloud into the ridges and pillars along its left-hand edge, which glow gold here against the bright turquoise face of the cloud. The small dark blobs near the cluster are dense pockets of gas and dust, known as Bok globules. The colours are enhanced for presentation and are an artistic rendering, not a map of which gas glows where. North is up and East is left, with the frame turned about 4.6 degrees clockwise from true north.
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Imaged in the early hours of 18 September 2026 with the John Cruickshank Telescope (GSO 16-inch Ritchey-Chretien) at the Anne H Cruickshank Observatory, 51cg (57.17 N, 2.10 W), on a tracking equatorial mount. Zeus 455M PRO camera, gain 300, 2x2 binning, sensor cooled to about -22 C.
- Field and scale: the image shown is 1600 x 1276 pixels at about 1.2 arcseconds per pixel, covering a field of about 32 x 26 arcminutes. It is the full frame (4788 x 3194 pixels, about 0.48 arcseconds per pixel) with the left-hand 16% trimmed off, reduced in size.
- Orientation: north is up and East is left, with the frame turned about 4.6 degrees clockwise from true north (north points slightly to the right of straight up). The image is not mirrored.
- Data: three 90 s narrowband exposures, 4.5 minutes in total, aligned by sub-pixel phase correlation and combined into a natural-palette colour image.
- Colour: starting from the natural-palette version, the sky was neutralised to near-black, the teal face of the cloud was shifted towards turquoise, and its warm red-brown edges were turned gold, brightened and given a soft glow; the colours were then strengthened. The stars were separated from the gas before the colours were changed and put back afterwards in their own colours.
- Processing: the gas was given a fresh brightness stretch, with the brightest parts of the face rolled off softly so they shine rather than clip, and the grain was reduced while keeping the stars sharp. The result was trimmed and resized for the web, and its midtones finally darkened slightly (a gamma adjustment) for richer colour.
- Capture times (BST), real timestamps from the saved subframes: 01:55:47, 01:59:00 and 02:00:18 (three subframes, 90 s each).
The Iris Nebula (NGC 7023, also Caldwell 4) in the constellation Cepheus, about 1,300 light-years away, is a reflection nebula: a cloud of interstellar dust that does not glow by itself but scatters the light of a hot young star embedded in it. That star, the bright point near the heart of the blue glow, is several times more massive than the Sun. Its light is scattered most strongly at blue wavelengths, in the same way that sunlight scattered by air makes the daytime sky blue, so the inner cloud shines blue. Dark lanes and filaments of thicker dust cross the bright centre and give the nebula its petal-like, flower shape. Around it lies a larger, much fainter cloud of dust, lit only dimly, which is shown here in warm brown and rust tones and which also blots out many of the background stars. The colours are strengthened for presentation. North is up and East is left.
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Imaged overnight on 1-2 November 2026 with the John Cruickshank Telescope (GSO 16-inch Ritchey-Chretien) at the Anne H Cruickshank Observatory, 51cg (57.17 N, 2.10 W), on a tracking equatorial mount (EQ8-R Pro). Zeus 455M PRO camera, gain 100, 2 x 2 binning, cooled to about -25 C. The nebula was centred by plate-solving, and many short exposures were taken between passing clouds.
- Field and scale: the image shown is 1600 x 1600 pixels at about 0.75 arcseconds per pixel, covering about 20 x 20 arcminutes centred on the nebula. It is cut from the full stacked image (0.48 arcseconds per pixel) and reduced in size.
- Data: luminance (L) 90 x 15 s, red 12 x 15 s, green 27 x 15 s and blue 17 x 15 s, about 36 minutes in total. Frames spoiled by cloud were left out.
- Luminance: every frame was plate-solved and aligned by its star positions, weighted by sky clarity and combined with outliers (satellite trails, hot pixels) rejected. The uneven sky background was modelled and removed, and the result stretched to show the faint dust without overexposing the bright centre.
- Colour: the red, green and blue frames were aligned and combined the same way, balanced so that the average field star is white, and combined with the luminance, which supplies all the brightness and detail. The colours were then strengthened, the outer dust given a warm brown-rust tone, the nebula and dust brightened slightly, and the sky darkened; the stars keep their own colours. The image was turned to north up, cropped, reduced in size and lightly sharpened.
- Capture times (GMT), by filter, real timestamps from the saved subframes:
- L: 23:01:08 to 01:15:17 (90 subframes used, 15 s each)
- R: 00:35:22 to 01:13:31 (12 used, 15 s each)
- G: 23:03:14 to 01:13:54 (27 used, 15 s each)
- B: 23:03:41 to 01:14:16 (17 used, 15 s each)
The Cocoon Nebula (IC 5146) is a cloud of glowing gas and dust in the constellation Cygnus, over 2,500 light-years away. It is lit from within by a young, hot star near its centre, whose ultraviolet light makes the surrounding hydrogen glow, and it surrounds a small cluster of young stars that formed from the cloud. The dark, ragged lanes and patches are dense dust in front of the glowing gas, and the nebula sits at the end of a long dark dust lane, Barnard 168, that stretches away beyond this frame. This is a Hubble-palette image, in which each colour shows the glow of one element: sulphur in red, hydrogen in green and oxygen in blue, with the green toned down. The Cocoon shines almost entirely in hydrogen and sulphur, so the whole cloud appears gold, with the colours strengthened for presentation; they map where each element shines rather than what the eye would see. North is up and East is left.
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Imaged on the evening of 19 September 2026 with the John Cruickshank Telescope (GSO 16-inch Ritchey-Chretien) at the Anne H Cruickshank Observatory, 51cg (57.17 N, 2.10 W), on a tracking equatorial mount (EQ8-R Pro). Zeus 455M PRO monochrome camera, 2x2 binned, gain 300, cooled to about -20 C.
- Field and scale: the image shown is 1280 x 1280 pixels, covering about 12 x 12 arcminutes around the nebula at about 0.55 arcseconds per pixel. It is cropped from the full image (4520 x 2781 pixels at about 0.48 arcseconds per pixel) and reduced in size.
- The data: 90 s exposures through narrowband filters - hydrogen-alpha 5, oxygen III 5 and sulphur II 3 - 19.5 minutes in total.
- Colour: the "Hubble palette" - sulphur to red, hydrogen to green, oxygen to blue - with part of the green toned down, which shows hydrogen- and sulphur-rich gas in gold. The weak oxygen signal was amplified 2.5 times before the colours were combined; it adds only a faint cool tint, as there is very little oxygen emission in the nebula. The colours were then strengthened, mainly in the brighter gas, and faint stars over the nebula take on some of the colour of the gas around them; other stars are shown close to white.
- Processing: every frame was plate-solved and aligned to a fraction of a pixel, the frames for each filter were combined with outlier rejection, the sky background was evened out and the noise was reduced. The brightness and fine detail come mainly from the hydrogen frames, which have the strongest signal, and the colour from smoothed versions of all three filters, which keeps the colour clean. The brightness was gently sharpened where there is real signal, the image turned to north up, and the nebula brightened with its highlights rolled off softly, the edges of the clouds and dust lanes lightly sharpened, and the result cropped around the nebula and resized for the web.
- Capture times (BST), real timestamps from the saved frames: hydrogen-alpha 22:00:49 to 22:07:19, oxygen III 22:08:58 to 22:15:22, sulphur II 22:17:02 to 22:20:12.
The Cygnus Wall is the brightest stretch of the North America Nebula (NGC 7000) in the constellation Cygnus, about 2,600 light-years away. The nebula is a vast cloud of glowing gas lit by young, hot stars, and the "wall" is the edge where the gas is densest and most strongly lit: their ultraviolet light makes the gas shine and is slowly eating into the cloud, carving it into the ridges, filaments and dark, dusty lanes seen here - including the dark cloud at lower right, whose outline forms the "Gulf of Mexico" of the North American shape - in a region where new stars are still forming. This is a Hubble-palette image: each colour shows the glow of one element, with hydrogen and sulphur in warm gold and oxygen in teal, so the colours map where each element shines rather than what the eye would see. North is up and East is left.
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Imaged on the night of 18-19 September 2026 with the John Cruickshank Telescope (GSO 16-inch Ritchey-Chretien) at the Anne H Cruickshank Observatory, 51cg (57.17 N, 2.10 W), on a tracking equatorial mount (EQ8-R Pro). Zeus 455M PRO monochrome camera, 2x2 binned, gain 300, cooled to about -19 C.
- Field and scale: the image shown is 1000 x 752 pixels, the whole image (not cropped), covering about 29 x 22 arcminutes at about 1.8 arcseconds per pixel. It is reduced in size from the full image (3661 x 2752 pixels at about 0.48 arcseconds per pixel).
- The data: one 90 s exposure through each of three narrowband filters - sulphur II, hydrogen-alpha and oxygen III - 4.5 minutes in total.
- Colour: the "Hubble palette" - sulphur to red, hydrogen to green, oxygen to blue - with most of the green toned down, which gives hydrogen-rich gas its gold colour and oxygen-rich gas its teal; the colours were then strengthened for presentation.
- Processing: the three frames were plate-solved and aligned to a fraction of a pixel, the sky background was evened out, and the noise was reduced. The brightness and fine detail come mainly from the hydrogen frame, which has the strongest signal, and the colour from smoothed versions of all three, which keeps the colour clean; stars keep their own colours. The brightness was gently sharpened where there is real signal and the image turned to north up and the edges trimmed. The grain in the gas was then smoothed, the edges of the dust lanes and ridges sharpened, the haze cleared and the nebula brightened with its highlights rolled off softly, and the result resized for the web.
- Capture times (BST), real timestamps from the saved frames: oxygen III 23:58:30, hydrogen-alpha 00:00:08, sulphur II 00:01:47 (each a single 90 s exposure).
The Wizard Nebula (NGC 7380) is a cloud of glowing gas in the constellation Cepheus, about 7,200 light-years away, lit by a young open cluster of hot stars at its heart. Their ultraviolet light makes the surrounding hydrogen glow, and their winds and radiation are carving the cloud into the ridges, cavities and dark, dusty pillars seen here; seen as a whole, the nebula's outline suggests a robed wizard, which gives it its name. This is a Hubble-palette image, in which each colour shows the glow of one element: gas glowing mostly in hydrogen appears gold, gas richer in sulphur turns orange to red - most of all in the bright knots on the eastern (left) side of the core - and oxygen shows as blue-violet around the central stars, mixing to magenta where it overlaps the sulphur-rich gas. The colours map where each element shines rather than what the eye would see. North is up and East is left.
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Imaged in the early morning of 18 September 2026 with the John Cruickshank Telescope (GSO 16-inch Ritchey-Chretien) at the Anne H Cruickshank Observatory, 51cg (57.17 N, 2.10 W), on a tracking equatorial mount (EQ8-R Pro). Zeus 455M PRO monochrome camera, 2x2 binned, gain 300, cooled to about -22 C.
- Field and scale: the image shown is 1600 x 1600 pixels, covering about 22 x 22 arcminutes at about 0.82 arcseconds per pixel. It is the full image (3627 x 2744 pixels at about 0.48 arcseconds per pixel) with the left-hand part, mostly empty star field, trimmed off to make it square, reduced in size.
- The data: one 90 s exposure through each of three narrowband filters - hydrogen-alpha, oxygen III and sulphur II - 4.5 minutes in total.
- Colour: the "Hubble palette" - sulphur to red, hydrogen to green, oxygen to blue - balanced across the nebula and with part of the green toned down, giving hydrogen-rich gas a gold colour and oxygen-rich gas a lavender-blue; the colours were then strengthened, mostly in the brighter gas, and the colour differences between the three filters brought out more strongly, so that sulphur-rich, hydrogen-rich and oxygen-rich gas stand apart. Stars are shown close to white, with the faintest stars over the nebula taking on some of the colour of the gas around them.
- Processing: the three frames were plate-solved and aligned to a fraction of a pixel, the sky background was evened out, and the noise was reduced. The brightness and fine detail come mainly from the hydrogen frame, which has the strongest signal, with the stars taken from the other two frames, and the colour from smoothed versions of all three, which keeps the colour clean. The brightness was gently sharpened where there is real signal and the image turned to north up and the edges trimmed. The nebula was then brightened, with its brightest parts rolled off softly, the edges of the clouds and dark lanes were sharpened, and the fine grain in the gas was smoothed. The colour differences were then taken from a separate rendering in which each filter is scaled on its own, smoothed so they carry no colour noise, and added on top in the brighter gas, with the stars and the faint fringes keeping their earlier colour. The result was trimmed on the left to a square and resized for the web with light noise reduction that keeps the stars and the edges of the gas.
- Capture times (BST), real timestamps from the saved frames: hydrogen-alpha 02:49:36, oxygen III 02:52:44, sulphur II 02:53:04 (each a single 90 s exposure).
The Crescent Nebula (NGC 6888) is a glowing shell of gas in the constellation Cygnus, about 5,000 light-years away. It was blown by a single star - a rare, massive and extremely hot Wolf-Rayet star near its centre - which is shedding its outer layers in a powerful stellar wind. That wind is ploughing into gas the star threw off earlier in its life, piling it up into this bubble, which spans about 25 light-years. In this Hubble-palette image the gold filaments are glowing hydrogen, densest along the north-eastern rim where the shock is strongest, while the blue filaments and the faint veil around the whole shell are the glow of oxygen, heated by the star's intense ultraviolet light - the colours map where each element shines rather than what the eye would see. The star itself is nearing the end of its life and is expected to explode as a supernova. North is up and East is left.
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Imaged on the evening of 17 September 2026 with the John Cruickshank Telescope (GSO 16-inch Ritchey-Chretien) at the Anne H Cruickshank Observatory, 51cg (57.17 N, 2.10 W), on a tracking equatorial mount (EQ8-R Pro). Zeus 455M PRO monochrome camera, 2x2 binned, gain 300, cooled to about -21 C.
- Field and scale: the image shown is 1600 x 1304 pixels, covering about 26 x 21 arcminutes centred on the nebula, at about 1.0 arcsecond per pixel. It is cropped from the full image (3823 x 2795 pixels at about 0.48 arcseconds per pixel) and reduced in size.
- The data: 90 s exposures through narrowband filters - one hydrogen-alpha frame and two oxygen III frames, 4.5 minutes in total.
- Colour: a Hubble-style palette - hydrogen shown gold and oxygen blue - with the colours strengthened for presentation. The brightest gold was softened so that its gradients and inner shading show instead of a flat bright patch, and the oxygen filaments were tinted blue so they stand out.
- Processing: the frames were plate-solved and aligned to a fraction of a pixel, the sky background was evened out, and the noise was reduced. The brightness and fine detail come from hydrogen and oxygen together, and the colour from smoothed versions of each, which keeps the colour clean; stars keep their own colours. The brightness was gently sharpened where there is real signal, the image turned to north up and the edges trimmed, the nebula brightened and its colours strengthened, and the result resized for the web.
- Capture times (BST), real timestamps from the saved frames: oxygen III 22:44:30 and 22:44:55, hydrogen-alpha 22:46:09 (each a single 90 s exposure).
The Eastern Veil Nebula (NGC 6992) is a small section of the Cygnus Loop, in the constellation Cygnus, about 1,470 to 2,400 light-years away: the expanding debris of a massive star that exploded as a supernova thousands of years ago. The blast wave is still ploughing through the thin gas around it, heating and compressing it into the long, tangled filaments seen here, which are sheets of glowing gas seen edge-on. This is a Hubble-palette image, in which each colour shows the glow of one element: sulphur in red, hydrogen in green and oxygen in blue, with the green toned down so that hydrogen and sulphur appear gold. The blue along the leading, left-hand edge of the filaments is oxygen, made to glow by the hottest gas just behind the shock front, while the gold filaments trail behind it; the colours map where each element shines rather than what the eye would see. North is up and East is left.
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Imaged on the evening of 18 September 2026 with the John Cruickshank Telescope (GSO 16-inch Ritchey-Chretien) at the Anne H Cruickshank Observatory, 51cg (57.17 N, 2.10 W), on a tracking equatorial mount (EQ8-R Pro). Zeus 455M PRO monochrome camera, 2x2 binned, gain 300, cooled to about -21 C.
- Field and scale: the image shown is 1800 x 1326 pixels, covering about 30 x 22 arcminutes at about 1.0 arcsecond per pixel. It is the full image (4536 x 2766 pixels at about 0.48 arcseconds per pixel) with the left-hand 17% trimmed off, reduced in size.
- The data: 90 s exposures through narrowband filters - hydrogen-alpha 4, sulphur II 4 and oxygen III 4 - 18 minutes in total.
- Colour: the "Hubble palette" - sulphur to red, hydrogen to green, oxygen to blue - with part of the green toned down, giving hydrogen- and sulphur-rich gas a gold colour and oxygen-rich gas blue, with the colours strengthened slightly for presentation. Stars are shown close to white.
- Processing: every frame was plate-solved and aligned to a fraction of a pixel, the frames for each filter were combined with outlier rejection, the sky background was evened out and the noise was reduced. The brightness and fine detail come mainly from the hydrogen frames, which have the strongest signal, and the colour from smoothed versions of all three filters, which keeps the colour clean. The brightness was gently sharpened where there is real signal, the image turned to north up, gently brightened with its highlights rolled off softly, and the empty star field on the left trimmed off before resizing for the web.
- Capture times (BST), real timestamps from the saved frames: hydrogen-alpha 23:10:25, 23:12:00, 23:13:35 and 23:37:38; sulphur II 23:15:13, 23:16:48, 23:18:23 and 23:39:15; oxygen III 23:20:02, 23:21:37, 23:23:13 and 23:35:59.
The Western Veil Nebula (NGC 6960, the "Witch's Broom") is a section of the Cygnus Loop, in the constellation Cygnus, about 2,100 to 2,400 light-years away: the expanding debris of a massive star that exploded as a supernova thousands of years ago. The blast wave is still ploughing through the thin gas around it, heating and compressing it into the long, delicate filaments seen here, which are sheets of glowing gas seen edge-on. This frame shows the southern part of the arc. This is a Hubble-palette image, in which each colour shows the glow of one element: sulphur in red, hydrogen in green and oxygen in blue, with the green toned down so that hydrogen and sulphur appear gold. In this part of the Veil the oxygen glow is strong, tracing the long blue-violet filaments of the shock front, with fainter gold hydrogen and sulphur wisps mostly on its inner, left-hand side; the colours map where each element shines rather than what the eye would see. North is up and East is left.
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Imaged on the evening of 18 September 2026 with the John Cruickshank Telescope (GSO 16-inch Ritchey-Chretien) at the Anne H Cruickshank Observatory, 51cg (57.17 N, 2.10 W), on a tracking equatorial mount (EQ8-R Pro). Zeus 455M PRO monochrome camera, 2x2 binned, gain 300, cooled to about -20 C.
- Field and scale: the image shown is 1800 x 1209 pixels, covering about 33 x 22 arcminutes at about 1.1 arcseconds per pixel. It is the full image (4530 x 2765 pixels at about 0.48 arcseconds per pixel) with the right-hand 9% trimmed off, reduced in size.
- The data: 90 s exposures through narrowband filters - hydrogen-alpha 3, sulphur II 3 and oxygen III 3 - 13.5 minutes in total.
- Colour: the "Hubble palette" - sulphur to red, hydrogen to green, oxygen to blue - with part of the green toned down, giving hydrogen- and sulphur-rich gas a gold colour and oxygen-rich gas blue-violet, with the colours strengthened for presentation. Stars are shown close to white.
- Processing: every frame was plate-solved and aligned to a fraction of a pixel, the frames for each filter were combined with outlier rejection, the sky background was evened out and the noise was reduced. The brightness and fine detail come mainly from the hydrogen frames and the colour from smoothed versions of all three filters, which keeps the colour clean. The brightness was gently sharpened where there is real signal, the image turned to north up and brightened to bring out the faint filaments, and the emptiest right-hand part of the field trimmed off before resizing for the web.
- Capture times (BST), real timestamps from the saved frames: oxygen III 22:17:14, 22:22:31 and 22:31:21; sulphur II 22:18:44, 22:23:18 and 22:28:05; hydrogen-alpha 22:20:14, 22:24:14 and 22:29:43.
NGC 7538, sometimes called the Northern Lagoon Nebula, is a cloud of glowing gas in the constellation Cepheus, about 9,100 light-years away, where new stars are being born. Its brightest region is lit by hot, young stars whose ultraviolet light makes the surrounding gas shine, while dense clumps deeper in the cloud are still collapsing to form more stars, some of them very massive. This is a Hubble-palette image, in which each colour shows the glow of one element: sulphur is shown in red, hydrogen in green and oxygen in blue. Each element's glow is shown at its own strength, so where they differ the colour changes: the heart of the cloud, rich in sulphur, glows orange, while the outer gas, where hydrogen dominates, turns gold and green, with darker lanes of dust between. The colours map where each element shines rather than what the eye would see; there is very little oxygen, so almost no blue. The points of light around it are stars in our own Galaxy. North is up and East is left.
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Imaged in the early hours of 18 September 2026 with the John Cruickshank Telescope (GSO 16-inch Ritchey-Chretien) at the Anne H Cruickshank Observatory, 51cg (57.17 N, 2.10 W), on a tracking equatorial mount (EQ8-R Pro). Zeus 455M PRO monochrome camera, 2x2 binned, gain 300, cooled to about -21 C.
- Field and scale: the image shown is 1800 x 1500 pixels, covering about 14.4 x 12 arcminutes around the nebula at about 0.48 arcseconds per pixel. It is cut from the full image (3621 x 2745 pixels) at full resolution, not reduced in size.
- The data: one 90 s exposure through each of three narrowband filters - hydrogen-alpha, oxygen III and sulphur II - 4.5 minutes in total.
- Colour: the "Hubble palette" - sulphur to red, hydrogen to green, oxygen to blue - with each filter's image scaled separately and the colour differences between them strengthened, so sulphur-rich gas shows orange and hydrogen-rich gas gold to green. The oxygen signal is too faint to add visible blue. Stars are shown white.
- Processing: the three frames were plate-solved and aligned to a fraction of a pixel, the sky background was evened out, and the noise was reduced. Each filter's image was scaled to its own faint and bright limits and its bright core compressed against its surroundings, so the structure in every filter shows, including inside the core. The brightness comes mainly from the hydrogen frame, which has the strongest signal, with local contrast added; the colour comes from lightly smoothed versions of all three. The image was turned to north up, the edges trimmed, the highlights rolled off softly, the sky darkened, and the grain gently reduced at fine and medium scales.
- Capture times (BST), real timestamps from the saved frames: oxygen III 03:05:06, hydrogen-alpha 03:06:36, sulphur II 03:08:06 (each a single 90 s exposure).
The Dumbbell Nebula (M27, NGC 6853) in the constellation Vulpecula, about 1,360 light-years away, is a planetary nebula: the glowing shell of gas thrown off by a dying Sun-like star, whose hot, faint core (a white dwarf) is all that remains of it. This vivid image uses the "Hubble palette", the scheme popularised by Hubble Space Telescope images, in which light from sulphur, hydrogen and oxygen is shown as red, green and blue. The inner region glows a bright blue, the shell a deep violet-blue, and the outer rims, where the gas is most strongly lit, stand out in yellow-green. The colours are strengthened for presentation. North is up and East is left.
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Imaged on 12 September 2026 (about 22:57 to 23:01 BST) with the John Cruickshank Telescope (GSO 16-inch Ritchey-Chretien) at the Anne H Cruickshank Observatory, 51cg (57.17 N, 2.10 W), on a tracking equatorial mount (EQ8-R Pro). Zeus 455M PRO camera, gain 213, cooled to about -21 C.
- Field and scale: the image shown is 1188 x 822 pixels, about 15 x 10 arcminutes, at about 0.75 arcseconds per pixel, cut from the full 4788 x 3194 frame, turned to north up (checked by plate solving) and reduced in size.
- Data: one 30 s exposure each through the SII, Ha and OIII narrowband filters, 1.5 minutes in total.
- Colour: SII mapped to red, Ha to green and OIII to blue, with the colours of the nebula strengthened for presentation; the stars keep their own colours.
- Processing: the three frames were aligned, colour-balanced and combined into a Hubble-palette colour image; a small dark halo around two stars, left by the alignment, was removed while keeping the star colours; the colour of the dark sky (which carried only noise) faded to neutral; a light denoise on brightness only; contrast increased and the image sharpened. For this version the colours of the nebula were strengthened, the contrast within the shell was increased, and the brightest areas were toned down slightly so their colour shows; the sky and the stars were left unchanged. The image was turned to north up, cropped and reduced in size for the web.
- Capture times (BST), real timestamps from the saved frames: SII 22:57:05, Ha 22:58:42 and OIII 23:01:38.
The Dumbbell Nebula (M27, NGC 6853) in the constellation Vulpecula, about 1,360 light-years away, is a planetary nebula: the glowing shell of gas thrown off by a dying Sun-like star, whose hot, faint core (a white dwarf) is all that remains of it. It was the first planetary nebula ever discovered, by Charles Messier in 1764, and the Sun will shed its own outer layers in the same way in about five billion years. In this vivid natural-palette image the bright inner region glows a pale blue-white, the outer lobes a rich teal, and the rim of the shell is edged in red. The colours are strengthened for presentation. North is up and East is left.
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Imaged on 12 September 2026 (about 22:57 to 23:01 BST) with the John Cruickshank Telescope (GSO 16-inch Ritchey-Chretien) at the Anne H Cruickshank Observatory, 51cg (57.17 N, 2.10 W), on a tracking equatorial mount (EQ8-R Pro). Zeus 455M PRO camera, gain 213, cooled to about -21 C.
- Field and scale: the image shown is 1188 x 822 pixels, about 15 x 10 arcminutes, at about 0.75 arcseconds per pixel, cut from the full frame (4788 x 3194 pixels, about 0.48 arcseconds per pixel) around the nebula, turned to north up (checked by plate solving) and reduced in size.
- Data: one 30 s exposure each through the SII, Ha and OIII narrowband filters, 1.5 minutes in total. The nebula is bright enough that short exposures are enough.
- Colour: a natural-looking palette from the three narrowband frames, with the colours of the nebula strengthened for presentation; stars are shown white.
- Processing: the three frames were aligned by sub-pixel phase correlation and combined into a colour image, with the large-scale sky gradient removed; the grain was reduced while keeping the arcs, edges and stars; contrast increased and the image sharpened. For this version the colours of the outer shell and rim were strengthened and the contrast in the fainter parts of the shell was increased, while the bright core keeps its original brightness and gradient; the sky and the stars were left unchanged. The image was turned to north up, cropped and reduced in size for the web.
- Capture times (BST), real timestamps from the saved frames: SII 22:57:05, Ha 22:58:42 and OIII 23:01:38.
The Bubble Nebula (NGC 7635) in the constellation Cassiopeia, 7,000 to 11,000 light-years away, is a shell of gas blown by the fierce wind of a single hot, massive young star, the bright star just inside the bubble's upper edge. The wind sweeps the surrounding cloud into a thin, nearly spherical skin several light-years across, which glows where the star's ultraviolet light strikes it. In this vivid Hubble-palette image the bubble shines blue against clumps and ridges of gold-coloured gas, the denser cloud the bubble is expanding into. The colours are an artistic rendering of the narrowband data, strengthened for presentation. North is up and East is left.
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Imaged in the early hours of 18 September 2026 (about 00:13 to 00:18 BST) with the John Cruickshank Telescope (GSO 16-inch Ritchey-Chretien) at the Anne H Cruickshank Observatory, 51cg (57.17 N, 2.10 W), on a tracking equatorial mount (EQ8-R Pro). Zeus 455M PRO monochrome camera, 2x2 binned, gain 300, cooled to about -21 C.
- Field and scale: the image shown is 1600 x 1600 pixels at about 0.7 arcseconds per pixel, covering about 19 x 19 arcminutes centred on the bubble. It is cut from the full image (about 0.48 arcseconds per pixel) and reduced in size.
- Data: three 90 s narrowband exposures, one each through the sulphur (SII), hydrogen-alpha (Ha) and oxygen (OIII) filters, 4.5 minutes in total.
- Colour: a Hubble-style rendering with the colours strengthened for presentation; the bubble's blue comes mainly from the oxygen frame. The sulphur frame holds very little signal, so the red is partly taken from the hydrogen frame. Stars are shown white.
- Processing: every frame was plate-solved and aligned to a fraction of a pixel, the sky background was evened out, the noise was reduced and the brightness lightly sharpened; the image was turned to north up, the gas brightened and its colours strengthened, the edges of the bubble and the clouds sharpened, and the coloured halos around the brightest stars removed. The result was cropped around the bubble and resized for the web.
- Capture times (BST), real timestamps from the saved frames: 00:14:30, 00:16:01 and 00:17:31.
The Bubble Nebula (NGC 7635) in the constellation Cassiopeia, 7,000 to 11,000 light-years away, is a shell of gas blown by the fierce wind of a single hot, massive young star, the bright star just inside the bubble's upper edge. The wind sweeps the surrounding cloud into a thin, nearly spherical skin several light-years across, which glows where the star's ultraviolet light strikes it. In this vivid natural-palette image the bubble glows a pale green against red-orange clumps and ridges of glowing hydrogen, the denser cloud the bubble is expanding into. The colours are strengthened for presentation. North is up and East is left.
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Imaged in the early hours of 18 September 2026 (about 00:13 to 00:18 BST) with the John Cruickshank Telescope (GSO 16-inch Ritchey-Chretien) at the Anne H Cruickshank Observatory, 51cg (57.17 N, 2.10 W), on a tracking equatorial mount (EQ8-R Pro). Zeus 455M PRO monochrome camera, 2x2 binned, gain 300, cooled to about -21 C.
- Field and scale: the image shown is 1600 x 1600 pixels at about 0.7 arcseconds per pixel, covering about 19 x 19 arcminutes centred on the bubble. It is cut from the full image (about 0.48 arcseconds per pixel) and reduced in size.
- Data: three 90 s narrowband exposures, one each through the sulphur (SII), hydrogen-alpha (Ha) and oxygen (OIII) filters, 4.5 minutes in total.
- Colour: a natural-looking palette from the three narrowband frames - hydrogen shown red, oxygen green-blue - with the colours strengthened for presentation. Stars are shown white.
- Processing: every frame was plate-solved and aligned to a fraction of a pixel, the sky background was evened out, the noise was reduced and the brightness lightly sharpened; the image was turned to north up, the gas brightened and its colours strengthened, the edges of the bubble and the clouds sharpened, and the coloured halos around the brightest stars removed. The result was cropped around the bubble and resized for the web.
- Capture times (BST), real timestamps from the saved frames: 00:14:30, 00:16:01 and 00:17:31.
Zeta Lyrae Double Star
The double star Zeta Lyrae in the constellation Lyra, over 150 light-years away, about two degrees from the brilliant star Vega. The two stars shown here, the brighter one with diffraction spikes at upper right and its fainter companion at lower left, are separated by only about 44 arcseconds, less than 1/40 of the width of the full Moon. They can be split with binoculars on a dark night. The rest of the picture is a rich field of much fainter and more distant stars.
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Imaged on 1 September 2026 at about 23:10 BST with the John Cruickshank Telescope (GSO 16-inch Ritchey-Chretien) at the Anne H Cruickshank Observatory, 51cg (57.17 N, 2.10 W), by remote control. Zeus 455M PRO camera on a tracking equatorial mount (EQ8-R Pro).
- Exposure: one frame of 1.07 seconds at high gain (465), with no filter, so the picture is black and white. The camera was not cooled for this frame.
- Field and scale: the image shown is 1769 x 1211 pixels, about 24.0 x 16.4 arcminutes, at about
0.81 arcseconds per pixel, cut from the full frame (9576 x 6388 pixels, about 0.24 arcseconds per
pixel), turned to north up (checked by plate solving) and reduced in size.
Saturn, the ringed giant of the Solar System, with four of its moons strung out on either side of it, imaged from Aberdeen on 11 September 2026. To the left of the planet is Dione; to the right, in order outwards, are Tethys, Rhea and the large bright moon Titan. Titan is bigger than the planet Mercury and is the only moon in the Solar System with a thick atmosphere. The moons all orbit close to the plane of Saturn's rings, which is why they line up almost exactly along the rings' direction. The rings are tilted only slightly towards us at present, so they appear as a thin bright ellipse crossing the planet, and the shadow of the rings and the pale cloud bands on Saturn's globe can be made out. Saturn was only about 27 degrees above the horizon, so its light passed through a lot of turbulent air and the picture is softer than the telescope could otherwise deliver. North is up and East is left.
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Imaged on the evening of 11 September 2026 with the John Cruickshank Telescope (GSO 16-inch Ritchey-Chretien) at the Anne H Cruickshank Observatory, 51cg (57.17 N, 2.10 W), on a tracking equatorial mount (EQ8-R Pro), by remote control. Zeus 455M PRO monochrome camera, 2x2 binned, gain 0, cooled to about -13 C. The telescope was pointed at Saturn using plate-solving navigation and target synchronisation.
- Field and scale: the image shown is 971 x 613 pixels, about 5.5 x 3.5 arcminutes, at about 0.34 arcseconds per pixel (measured from the moons' positions). The camera's own frames are at about 0.48 arcseconds per pixel; the stacked image was enlarged slightly when it was made.
- The data: a video of 874 frames, each a 10.5 millisecond exposure with no filter (black and white), recorded at about 3.4 frames per second over 4.3 minutes. The 150 sharpest of 830 aligned frames were averaged, which reduces the blurring effect of the atmosphere.
- Colour: none - this is a black-and-white image taken without a filter.
- Processing: the frames were aligned on Saturn, the sharpest selected and averaged, and the result turned to put north exactly up, using the moons' predicted positions on the sky. The blur shown by the moons was measured and removed from the full-depth stack; the planet was stretched gently and sharpened to bring out its bands and the ring shadow, and the much fainter moons were brightened and sharpened separately so all four show clearly. The moons are far too small for this telescope to show any surface or shape: the turbulent air had smeared and doubled their images, so each is shown as a round point at its measured position.
- Capture time (BST), from the video file's own timestamps: 22:59:58 to 23:04:16.
