Astrophotography
Astrophotography
Welcome to the astro-imaging album of the Anne H Cruickshank Observatory (ACO) at the 黑料网. 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 how it was made.
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.
* * *
Imaged overnight on 21-22 September 2026 with the John Cruickshank Telescope (GSO 16-inch
Ritchey-Chretien) at the Anne H Cruickshank Observatory, 黑料网 (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 below 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.
* * *
Imaged overnight on 21-22 September 2026 with the John Cruickshank Telescope (GSO 16-inch
Ritchey-Chretien) at the Anne H Cruickshank Observatory, 黑料网 (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. Faint dark smudges just beside the galaxy's core are a
residual trace of this patch, not features of the galaxy.
- 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.
* * *
Imaged overnight on 18-19 October 2026 with the John Cruickshank Telescope (GSO 16-inch
Ritchey-Chretien) at the Anne H Cruickshank Observatory, 黑料网 (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.
* * *
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, University of
Aberdeen (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.
* * *
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, 黑料网 (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)
M33 Triangulum Galaxy
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.
* * *
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, University of
Aberdeen (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 1596 x 1064 pixels at about 1.44 arcseconds per pixel,
covering about 38 x 26 arcminutes - the camera's full field (about 0.24 arcseconds per pixel, no
binning), reduced in size.
- 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.
* * *
Imaged on the evening of 23 September 2026 with the John Cruickshank Telescope (GSO 16-inch
Ritchey-Chretien) at the Anne H Cruickshank Observatory, 黑料网 (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 1500 x 1011 pixels at about 0.58 arcseconds per pixel,
covering about 14.4 x 9.7 arcminutes centred on the galaxy. It is reduced in size from the full
processed image (3607 x 2431 pixels, 0.24 arcseconds per pixel).
- 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, 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 stars keep their
own colours. The image was 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.
* * *
Imaged overnight on 21-22 September 2026 with the John Cruickshank Telescope (GSO 16-inch
Ritchey-Chretien) at the Anne H Cruickshank Observatory, 黑料网 (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 1850 x 1600 pixels at the camera's full binned resolution,
about 0.48 arcseconds per pixel, covering about 14.8 x 12.8 arcminutes. 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.
- 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. In colour, the cluster tells its own story: the scattered golden stars are red giants,
old stars that have swollen near the end of their lives, while the cluster's overall white-blue glow
comes from many hot, blue stars that have passed that stage - M15 is unusually rich in them 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.
* * *
Imaged on the evening of 30 September 2026 with the John Cruickshank Telescope (GSO 16-inch
Ritchey-Chretien) at the Anne H Cruickshank Observatory, 黑料网 (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 1800 x 1500 pixels, covering about 19 x 16 arcminutes around
the cluster at about 0.64 arcseconds per pixel. It is a 2400 x 2000 pixel crop of the full colour
stack (about 0.48 arcseconds per pixel), 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)
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.
* * *
Imaged on the evening of 19 September 2026 with the John Cruickshank Telescope (GSO 16-inch
Ritchey-Chretien) at the Anne H Cruickshank Observatory, 黑料网 (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.
* * *
Imaged on the evening of 19 September 2026 with the John Cruickshank Telescope (GSO 16-inch
Ritchey-Chretien) at the Anne H Cruickshank Observatory, 黑料网 (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. For
this version 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.
* * *
Imaged on the evening of 18 September 2026 with the John Cruickshank Telescope (GSO 16-inch
Ritchey-Chretien) at the Anne H Cruickshank Observatory, 黑料网 (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.
- 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.
* * *
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, 黑料网 (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.
- 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.
* * *
Imaged overnight on 1-2 November 2026 with the John Cruickshank Telescope (GSO 16-inch
Ritchey-Chretien) at the Anne H Cruickshank Observatory, 黑料网 (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.
* * *
Imaged on the evening of 19 September 2026 with the John Cruickshank Telescope (GSO 16-inch
Ritchey-Chretien) at the Anne H Cruickshank Observatory, 黑料网 (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.
* * *
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, 黑料网 (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: hydrogen and sulphur appear gold, and oxygen lavender-blue - strongest
towards the edges of the cloud, away from the bright hydrogen-rich core - so the colours map where
each element shines rather than what the eye would see. North is up and East is left.
* * *
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, 黑料网 (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 1210 pixels, the whole image (not cropped), covering
about 29 x 22 arcminutes at about 1.1 arcseconds per pixel. It is reduced in size from the full
image (3627 x 2744 pixels at about 0.48 arcseconds per pixel).
- 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 gold and blue pushed slightly further 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
result was 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.
* * *
Imaged on the evening of 17 September 2026 with the John Cruickshank Telescope (GSO 16-inch
Ritchey-Chretien) at the Anne H Cruickshank Observatory, 黑料网 (57.17 N, 2.10 W),
on a tracking equatorial mount (EQ8-R Pro), by ACO AI autonomous and remote control. 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.
* * *
Imaged on the evening of 18 September 2026 with the John Cruickshank Telescope (GSO 16-inch
Ritchey-Chretien) at the Anne H Cruickshank Observatory, 黑料网 (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.
* * *
Imaged on the evening of 18 September 2026 with the John Cruickshank Telescope (GSO 16-inch
Ritchey-Chretien) at the Anne H Cruickshank Observatory, 黑料网 (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 hydrogen shine,
while dense clumps deeper in the cloud are still collapsing to form more stars, some of them very
massive. In this natural-palette image the glowing hydrogen appears red, brightest and palest
towards the heart of the cloud, with darker lanes of dust and fainter wisps of gas around it. The
nebula shines almost entirely in the light of hydrogen; its oxygen glow is very faint, which is why
there is so little blue or green in the gas. The points of light around it are stars in our own
Galaxy. North is up and East is left.
* * *
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, 黑料网 (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 1280 x 970 pixels, covering about 16 x 12 arcminutes around
the nebula at about 0.75 arcseconds per pixel. It is cropped from the full image (3621 x 2745
pixels at about 0.48 arcseconds per pixel) and 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: a natural palette built from the narrowband frames - hydrogen and sulphur to red, oxygen
to green and blue - which approximates the nebula's real colours. The brightest part of the core,
where the red is at full strength, is shown fading to a paler pink so that its brightness gradient
shows. 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. 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. The brightness was gently sharpened where there is real
signal, the image turned to north up and the edges trimmed, the nebula gently brightened with its
highlights rolled off softly, the sky darkened and smoothed, and the result cropped and resized
for the web.
- 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.
* * *
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, 黑料网 (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.
* * *
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, 黑料网 (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.
* * *
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, University of
Aberdeen (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.
* * *
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, University of
Aberdeen (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.
* * *
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, 黑料网 (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 just
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.
* * *
Imaged on the evening of 11 September 2026 with the John Cruickshank Telescope (GSO 16-inch
Ritchey-Chretien) at the Anne H Cruickshank Observatory, 黑料网 (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
stretched to show both the bright planet and the much fainter moons. The image was then turned by
1.5 degrees to put north exactly up, using the moons' predicted positions on the sky. Finally the
image was sharpened: the blur shown by the moons (a slight smear, mostly side to side, from the
turbulent air and tracking) was measured and removed, so the moons appear as small points, with a
gentler sharpening on the planet itself, and the brightness was lowered slightly so the brightest
parts are not burnt out.
- Capture time (BST), from the video file's own timestamps: 22:59:58 to 23:04:16.
