Curving across the Autumn night sky somewhat alone in the Perseus constellation, is the large (100 light-years ~ 2.50o) California Nebula. Being something of a prelude to the arrival of Orion and all its exciting objects, I have somewhat neglected this astronomical behemoth, only imaging it for short periods from time to time in the past. Despite continuing poor conditions and with some difficulty, on this occasion I manged nearly 8-hours integration, which with careful processing has brought out the true majesty of this exciting feature.
The final image has been flipped 180 degrees, which for some reason seems to enhance the depth?
An emission nebula located some 1,000 light years from Earth, the billowing clouds of hydrogen and sulphur gases and dust, and the faint, wispy veil of oxygen are clearly evident in this powerful SHO image. The intense ultraviolet radiation from the nearby massive star Menkib – with a surface temperature of about 37,000 K and radiation 330,000 times greater than our Sun – plays a key role in ionizing the gasses of the nebula, which ultimately brings this majestic monster to life.
IMAGING DETAILS
Object
NGC 1499 AKA California Nebula
Constellation
Perseus
Distance
1,000 light-years
Size
2.50o ~ 100 light-years
Apparent Magnitude
Various
Scope
William Optics GT81 + Focal Reducer FL 382mm f4.72
Mount
ZWO AM5 + ASIair plus
Guiding
William Optics 50mm guide scope
ZWO120MM mini
Camera
ZWO ASI294MM CMOS sensor
FOV 2.87o x 1.96o Resolution 2.50”/pix Max. image size 4,144 x 2,822 pix
EFW
ZWOx8 EFW & 31mm Chroma Ha, OIII, SII filters
Capture & Processing
ASIair plus, Deep Sky Stacker & PixInsight v1.8.9-3
Image Location & Orientation
Centre = RA 03:59:32.52 DEC +36:37:20.1 Bottom = North
Exposures
Ha x32 + OIII x33 + SII x28 x 300 sec Total Integration Time: 7hr 45 min
@ Gain 120 @ -20oC
Calibration
5 x 300 sec Darks 10 x NB Flats & Dark Flats @ ADU 32,000
Location & Darkness
Fairvale Observatory – Redhill – Surrey – UK Typically Bortle 5-6
It’s at this time of the year I turn my attention to Cygnus and the plethora of imaging opportunities it provides, which inevitably tend to be narrowband targets. This year it is IC 5068, a low emission nebula often overlooked because of its location near the more popular North American and Pelican nebulae, as well as many other fabulous targets within the adjacent Cygnus molecular cloud, and as a result is unfortunately known as the Forsaken Nebula!
Located just below the Pelican Nebula and close to the blue supergiant Deneb star (see above), this complex area is known for the graphically shaped streaks of cold, dark dust clouds that criss-cross the dense, brightly coloured gas regions of nebulosity.
As a narrowband target my initial choice of image processing was the traditional Hubble Palette SHO configuration, which as envisaged, resulted in an exciting and colourful rendition of the busy IC 5068 (see image below). Notwithstanding, having recently discovered some other, fairly new Pixinsight processing techniques (NB Color Mapper & NB Image Blend), I decided to give them a try to produce an alternative blended HOO–S image. Though still very much recognisable as IC 5068, the resulting (warm) colours and details reveal a very different and perhaps more dynamic image (see image at the top of the page).
Narrowband images leave much to the imagination when processing and often take on a stirring look when completed. In the case of IC 5068, each of the images produced seem to have the feel of abstract art, whilst at the same time posing many questions regarding the origin of many unusual features. I believe this exciting region deserves much greater attention and should belong in the pantheon of popular Cygnus objects such as the North American, Pelican & Veil nebulae. Moreover, the so-called Foresaken Nebula warrants a name more befitting of its exciting beauty.
IMAGING DETAILS
Object
IC5068
Constellation
Cygnus
Distance
1,600 light-years
Apparent Magnitude
Various
Scope
William Optics GT81 + Focal Reducer FL 382mm f4.72
Mount
ZWO AM5 + ASIair plus
Guiding
William Optics 50mm guide scope
ZWO120MM mini
Camera
ZWO ASI294MM CMOS sensor
FOV 2.87o x 1.96o Resolution 2.50”/pix Max. image size 4,144 x 2,822 pix
EFW
ZWOx8 EFW & 31mm Chroma Ha, OIII, SII filters
Capture & Processing
ASIair plus, Deep Sky Stacker & PixInsight v1.8.9-3
Image Location & Orientation
Centre = RA 20:51:16.50 DEC +42::30 : 05.30 Top = North
Exposures
Ha x56 + OIII x46 + SII x44 x 300 sec Total Integration Time: 12hr 10 min
@ Gain 120 @ -20oC
Calibration
5 x 300 sec Darks 10 x NB Flats & Dark Flats @ ADU 32,000
Location & Darkness
Fairvale Observatory – Redhill – Surrey – UK Typically Bortle 5-6
Date & Time
14th 18th 19th September + 3rd & 10th October 2024 +20.15h
My astrophotography journey started just over 10-years ago and looking back, it’s clear that my timing was fortuitous, as over this period we have seen several developments that have completely transformed the hobby for amateurs.
Wide availability of high-quality telescopes for relatively modest prices
Development of CMOS sensor cameras
Major advances of image capture and processing software
Introduction of AI to image processing
And the changes just keep coming.
When not imaging or processing, I’m sure that many astrophotographers spend too much time looking online at new equipment, particularly telescopes and cameras! However, when my journey started in about 2014, it didn’t take long to discover that perhaps the mount is the most important piece of equipment. I started observing with a Skywatcher 150PL on a EQ3-2 mount ( see above ) but soon thereafter discovered astrophotography, which required the addition of a small motor for tracking. It was fun but completely inadequate for good imaging, so then moved onto a William Optics GT81 triplet refractor on a Skywatcher AZ-EQ6 GT mount ( see below ), which completely changed everything and, more importantly, gradually resulted in better images.
My trusty, but oh so heavy AZ-EQ6 GT mount
I continue to use the AZ-EQ6 GT, which technically remains an excellent mount, but it is very heavy and frankly has become more and more tedious to set-up and take down each time, whilst moreover, my back is finding it too much hard work. It is said that necessity is the mother of invention and so a completely new type of mount slowly emerged on the market last year, that is now becoming nothing less than a revolution. It seems too good to be true, but its features are:
Small & light weight
High load capacity that doesn’t require counterweights
No need to be balanced
High torque
Low if any backlash
Apart from the weight issue, commonly used GEM mounts are based on worm gears, which inevitably suffer from backlash, that can be a major problem for astrophotography. Although this can be minimised with good set-up and various software, it will always remain a problem. The new harmonic drive or strain wave mounts are based on completely different technology, that surprisingly has been used for many years in avionics and robotics, making it tried and tested technology. A strain wave mount uses a flexible spline and a rotating elliptical plug to transmit motion and achieve high precision and torque, which allows for large payloads in a compact and portable package ( see images immediately below ) . Click HERE for more technical information. Initially there were only a few manufacturers of Harmonic / Strain Wave mounts but now the word’s out and all manufacturers are rushing to join the game.
Over the past decade the Chinese technology company ZWO Optical have emerged as a dominant force and leading innovator in astrophotography; I’ve been using various excellent ZWO CMOS cameras since 2015. It was therefore no surprise that ZWO were amongst the first to launch a Harmonic Drive mount, initially the AM3 then the AM5 which is what I purchased earlier this year; the main difference between the two is capacity, the AM5 being greater. For various reasons, personal and being busy imaging with the AZ-EQ6 GT, I only got round to using the AM5 in August ( see below) and have not been disappointed.
One of ZWO’s quirks is that, where possible, their equipment is often only compatible with other ZWO products. It can be a bit of a problem but given the quality of their equipment I’m not usually put off. Notwithstanding, the AM5 will fit some other tripods but in this case, I chose to purchase the excellent and super lightweight ZWO TC40 carbon fibre tripod, together with the ZWO PE200 pier extension, which reduces the likelihood of the OTA / camera colliding with the tripod. Like my previous experience of ZWO equipment, everything is well designed and exceptionally well made. Moreover, it is substantially lighter than my AZ-EQ6 mount!
Although not essential, to reduce the set-up / take-down time as well as provide convenient integrated control and capture software, I also chose to get ZWO’s well tested and popular ASIair Plus, which can easily be attached either to the mount or scope. Basically, it is a very small astrophotography computer / controller, which can also help manage various power requirements such as cameras and dew straps. Finally, and because for now I wanted to piggyback my existing William Optics GT81 scope which uses a Lodestar X2 guiding camera that is incompatible with the ZWO equipment, I added a dedicated 50mm William Optics 50mm guide scope with a ZWO ASI120MM mini guide camera.
The AM5 mount, ASIair plus (on the left) and OTA rig. It looks busy but once the rig is established it just lifts into place and connects in less than 5 minutes and you’re ready to go!
Finally, only in recent weeks have I had the chance and weather conditions to set-up and try out this new equipment. The early results have been good so far and I hope the limited integration time of the image here will be just a taster of what is to come. The AM5 itself has been a breeze to use and its light weight and set-up is clearly going to revolutionise my astrophotography but the ASIair plus is also a significant game changer that I’m still getting to grips with.
The ASIair plus delivers an excellent and mostly, easy-to-use experience, which with time I’m sure I’ll get to love but to miniaturise and streamline operating compared to my current set-up and control equipment and software, I find it lacking in finesse. Notwithstanding, it is an incredible piece of equipment that works very well with the AM5 mount. I am particularly impressed by the Polar Alignment and Meridian Flip functions, of which the latter is just amazing!
All-in-all the weight and convenience of the AM5 together with the other ZWO equipment is likely to result in a better and importantly, fun time when imaging. In particular, with a truly portable set-up I’m hoping to revisit the end of my garden, from where I can see the north sky and all its objects, hitherto obscured by my house, and maybe even get to image at some dark sites, we shall see – these are certainly changing times, which so far I’ve really enjoying.
IMAGING DETAILS
Object
NGC 7000 North American & Pelican Nebulae
Constellation
Cygnus
Distance
2,590 light-years
Size
120 x 100 arc mins
Apparent Magnitude
Various
Scope
William Optics GT81 + Focal Reducer FL 382mm f4.72
Mount
ZWO AM5 + ASIair plus
Guiding
William Optics 50mm guide scope
ZWO120MM mini guide camera
Camera
ZWO ASI294MM CMOS sensor
FOV 2.87o x 1.96o Resolution 2.50”/pix Max. image size 4,144 x 2,822 pix
EFW
ZWOx8 EFW & 31mm Chroma Ha, OIII, SII filters
Capture & Processing
ZWO ASIair plus, Deep Sky Stacker & PixInsight v1.8.9-3
Image Location & Orientation
Centre = RA 20:55:42.97 DEC +44:20:53.80 Top = North
Exposures
Ha x11 + OIII x13 + SII x13 x 300 sec Total Integration Time: 3hr 05 min
@ Gain 120 @ -20oC
Calibration
5 x 300 sec Darks 10 x NB Flats & Dark Flats @ ADU 32,000
Location & Darkness
Fairvale Observatory – Redhill – Surrey – UK Typically Bortle 5-6
Hind’s Variable Nebula (NGC1555) is situated 400 light-years away in the region between Aldebaran and the Pleiades, in the constellation Taurus, in the same area as the Hyades (see below). The nebula is a Herbig-Haro object – a bright patch of nebulosity in which new stars are forming – which changes in apparent size and brightness. It is illuminated by the young pre-main sequence triple star system T-Tauri and was discovered by the English astronomer John Russell Hind in 1852.
Close-up (cropped) version of Hind’s Variable Nebula
The data for this image was obtained from the Deep Sky West (DSW) site in New Mexico using a Takahashi FSQ 106 paired with a QSI 683-WSG8 camera, which provides a widefield view of the nebula (see top of the page), thereby including many colourful bright stars that dominate this area. The addition of Ha data further highlights the complex nature of the region which is not fully seen in an LRGB image.
It might seem paradoxical but sometimes it is the absence of light that makes an astrophotography image interesting. Such a feature is the so-called Aquila Rift, a vast, dark interstellar cloud that spans the constellations of Aquila (Eagle), Serpens Cauda and eastern Ophiuchus. Towards the central section of the rift, about 600 million light-years from Earth, within the Aquila constellation and not far from the Summer Triangle’s Altair star, is Lynd’s Dark Nebula (LDN) 673.
Some 7-light years in size, this fragmented dark molecular cloud complex contrasts well against the colourful molecular clouds and stars of the Milky Way; the very dense dust of the dark nebulae scatters the blue light of the surrounding stars, producing a yellow-red bias. In places the density within the nebula that energetic outflows can be seen in the form of the red nebulosity of RNO 109 and Herbig-Haro object HH-32.
Whilst the highlight is the alluring bright blue reflection nebula NGC 7023 AKA Iris Nebula, careful processing reveals that this celestial flower is enveloped within a vast region of interstellar dust, altogether making for a spectacular image. Strictly speaking NGC 7023 refers to an open cluster within the reflection nebula, which is itself illuminated by a magnitude +7.4 star designated HD 200775 – the cropped starless image shows the beautiful detail that makes up the Iris ‘flower’.
The first galaxies were identified in the 17th Century by the French astronomer Charles Messier, although at the time he did not know what they were. It was only when in 1924 American astronomer Edwin Hubble measured the distance to the Andromeda galaxy using cepheid variables, that the existence of other galaxies was finally established. One hundred years on it’s now estimated that there are between 200 billion and 2 trillion galaxies in the Universe; as Douglas Adams said in the Hitchhikers Guide to the Galaxy, “Space…….is really big”!
For astronomers this time of the year is generally referred to the ‘Galaxy Season’, as our view of the Milky Way from Earth changes from the winter sky of the Orion Spur and Perseus Arm to the summer view with Cygnus overhead down to Sagittarius in the south, in between we’re looking into deep space. With very few exceptions, galaxies are located very far from Earth, which from our perspective makes them small and therefore a challenge for my imaging equipment. However, this Spring I’ve been imaging the spectacular Leo Galaxy Cluster, a mere 330 million light-years from Earth (see cropped version of cluster at the top of the page).
Containing at least 70 major galaxies, the Leo Cluster unusually consists mostly of spiral galaxies, which are best seen here cropped from the original widefield image. The bright elliptical galaxy near the centre of the image, NGC 3842, has one of the largest known black holes in the universe, which is about 10 billion times more massive than our sun!
We have come a long way since Galileo Galilei published his astronomical treatise Sidereus Nuncius AKA Starry Messenger in 1610, the first scientific publication based on observations made through a telescope. Galileo’s work completely changed the way humanity understood the night sky and, by extension, our place in space, later leading to the acceptance of the heliocentric model of the planets. Profound as that was, our understanding of the Universe since 1924 has even greater implications. Moreover, the ability for an amateur to image something like the Leo Cluster from my back garden is exciting and very rewarding (see widefield version above+ image location + orientation where the red dot = top left of image).
IMAGING DETAILS
Object
Leo Galaxy Cluster
Constellation
Leo
Distance
330 million light-years
Size
Various
Apparent Magnitude
Various
Scope
William Optics GT81 + Focal Reducer FL 382mm f4.72
Mount
SW AZ-EQ6 GT + EQASCOM computer control & Cartes du Ciel
Guiding
William Optics 50mm guide scope
+ Starlight Xpress Lodestar X2 camera & PHD2 guiding
Camera
ZWO ASI294MM CMOS sensor
FOV 2.87o x 1.96o Resolution 2.50”/pix Max. image size 4,144 x 2,822 pix
EFW
ZWOx8 EFW & 31mm LRGB filters
Capture & Processing
Astro Photography Tool (APT), Deep Sky Stacker & PixInsight v1.8.9-2
Image Location & Orientation
Centre = RA 11:44:12.40 DEC +19:50:25.70 Right = North
Exposures
L x30 + R x31 + G x31 + B x 31 @ 180 sec Total Integration Time: 6hr 9min
@ Gain 120 & 30 Offset 21 @ -15oC
Calibration
10 x 180 sec Darks + 10 x BB Flats & Dark Flats @ ADU 32,000
Location & Darkness
Fairvale Observatory – Redhill – Surrey – UK Typically Bortle 5-6
Like many astrophotographers, the Rosette Nebula holds a special attraction for me; it’s size, details and colours produce a perfect narrowband target. I revisited the old favourite again this year for the fourth time since 2015 (+2017 & 2018), in an attempt to capture even better its unique and dynamic beauty using newer equipment, skills, and techniques.
Located approximately 5,000 light-years away, this vast cloud of gas and dust has been sculpted into a distinctive rose-like shape. The central star cluster (NGC 2237) has blown-away a large hole within the surrounding molecular cloud (NGC 2244), which all together is some 1.7 degrees or 150 light-years in diameter. Numerous star-producing dark Bok globules are visible along the upper-left, central quadrant of the nebula, collectively referred to as the “Carnival of Animals”.
The skies this winter have been poor and, as a result, imaging possibilities have been very limited. However, over five nights from January to March I was eventually able to obtain 9-hours of Ha, OIII and SII integration time which, moreover, produced a good data set of 10-minute exposures.
I’m very pleased with the final SHO image (top of the page), which successfully displays the intricate details and colours that arise from the aforesaid make-up and processes that makes the nebula so popular. Furthermore, experimenting with an HSS palette produced an alternative and exciting image of this rose of night sky (see above), that might be even more in-keeping with its given moniker. All-in-all, despite this year’s difficulties I’m satisfied that I gave the Rosette my best shot, which is definitely a cut above my previous attempts – though I fully expect to return again in a few years seeking further improvements.
IMAGING DETAILS
Object
Rosette Nebula NGC 2244 + 2237, 2238, 2239 & 2246
Constellation
Monoceros
Distance
5,000 light-years
Size
Approx. 100 light-years ~ 1.3o
Apparent Magnitude
+9.0
Scope
William Optics GT81 + Focal Reducer FL 382mm f4.72
Mount
SW AZ-EQ6 GT + EQASCOM computer control & Cartes du Ciel
Guiding
William Optics 50mm guide scope
+ Starlight Xpress Lodestar X2 camera & PHD2 guiding
Camera
ZWO ASI294MM CMOS sensor
FOV 2.87o x 1.96o Resolution 2.50”/pix Max. image size 4,144 x 2,822 pix
EFW
ZWOx8 EFW & 31mm Chroma Ha, OIII, SII filters
Capture & Processing
Astro Photography Tool (APT), Deep Sky Stacker & PixInsight v1.8.9-2
Image Location & Orientation
Centre = RA 06:31:55.304 DEC +05:00:56.913 Left = North
Exposures
Ha x18 + OIII x18 + SII x18 x 600 sec R x20 + G x20 + B x20 x 60sec Total Integration Time: 10hr
@ Gain 120 & 30 Offset 21 @ -15oC
Calibration
5 x 600 sec Darks 10 x NB Flats & Dark Flats @ ADU 32,000
Location & Darkness
Fairvale Observatory – Redhill – Surrey – UK Typically Bortle 5-6
Date & Time
19th January, 12th February, 6th 7th March 2024 @ +20.00h
Located 3,650 light-years from Earth, in the area between the Monoceros and Canis Major constellations, is the emission and reflection nebulae complex of the so-called Seagull Nebula. It’s been 8-years since I last briefly dabbled with imaging this exciting object and for good reason. From my position, this bird flies at a maximum 28o above the southern horizon (-11 DEC) and, furthermore, spends much of its time behind houses, trees, and tall hedges, thus providing just two short windows for imaging; combined with this winter’s terrible weather it made for a tough but ultimately rewarding target.
The Seagull’s approximate flight path seen from Fairvale Observatory makes imaging difficult
Whilst popularly known as the Seagull Nebula, the bird consists of a number of fabulous objects spanning some 200 light-years in their entirety: the Seagull’s head (SH2-292) and wings (IC 2177), the large open star cluster along the leading edge of the left wing (NGC 2335) and a smaller cluster on the edge of the right wing (NGC 2327), the nebula at the tip of the right wing (Sh2-297), as well as many other named features (Sharpless and LBN) that are highlighted in the following plate solved image (below).
Despite the difficulties posed by the low transit of the bird in the night sky, each of the Ha, OIII and SII wavelengths are strong, making for good data acquisition and a very pleasing final SHO image.
IMAGING DETAILS
Object
Seagull Nebula (SH2-292, IC2177 etc.)
Constellation
Monoceros
Distance
3,650 light-years
Size
Approx. 200 light-years
Apparent Magnitude
Various
Scope
William Optics GT81 + Focal Reducer FL 382mm f4.72
Mount
SW AZ-EQ6 GT + EQASCOM computer control & Cartes du Ciel
Guiding
William Optics 50mm guide scope
+ Starlight Xpress Lodestar X2 camera & PHD2 guiding
Camera
ZWO ASI294MM CMOS sensor
FOV 2.87o x 1.96o Resolution 2.50”/pix Max. image size 4,144 x 2,822 pix
EFW
ZWOx8 EFW & 31mm Chroma Ha, OIII, SII filters
Capture & Processing
Astro Photography Tool (APT), Deep Sky Stacker & PixInsight v1.8.9-2
Image Location & Orientation
Centre = RA 07:06:42.425 DEC -11:18:53.372 Left = North Top = West
Exposures
Ha x16 + OIII x13 + SII x14 @ 600 sec Total Integration Time: 7hr 10 min
@ Gain 120 & 30 Offset 21 @ -15oC
Calibration
5 x 300 sec Darks 10 x NB Flats & Dark Flats @ ADU 32,000
Location & Darkness
Fairvale Observatory – Redhill – Surrey – UK Typically Bortle 5-6
Date & Time
18th 19th January 11th 12th February 2023 @ +20.30h
Located northeast (left) of Pleiades, south of California Nebula and north (above) of Aldebaran, spanning more than 30o of the night sky is the Taurus Molecular Cloud (TMC), a rich area of dark nebulae punctuated by bright areas of new star formation. Moreover, the TMC is thought to be the nearest star forming region to Earth.
Herschel Space Observatory far-infrared’s view of the TMC & approximate image location
All-in-all, the very large TMC provides many promising imaging opportunities. This image captures numerous, complex dark nebulae across the field-of-view, including Barnard 10 & 214, LDN 1495 & VdB 27, together with bright reflection nebulae LBN 782 & 785 and the odd galaxy – if you look carefully.
IMAGING DETAILS
Object
Barnard 10, VdB 27, LBN 782 & 785
Constellation
Taurus
Distance
450 light-years
Scope
William Optics GT81 + Focal Reducer FL 382mm f4.72
Mount
SW AZ-EQ6 GT + EQASCOM computer control & Cartes du Ciel
Guiding
William Optics 50mm guide scope
+ Starlight Xpress Lodestar X2 camera & PHD2 guiding
Camera
ZWO ASI294MM CMOS sensor
FOV 2.87o x 1.96o Resolution 2.50”/pix Max. image size 4,144 x 2,822 pix
EFW
ZWOx8 EFW & LRGB 31mm Chroma filters
Capture & Processing
Astro Photography Tool (APT), Deep Sky Stacker & PixInsight v1.8.9-2
Image Location & Orientation
Centre = RA 04:20:19.60 DEC +27:22:.07.66 Right = North
Exposures
L x50, R x30, G x31, B x27 x300 sec Total Integration Time: 11hr 30 min
@ Gain 120 & Offset 30 @ -15oC
Calibration
5 x 300 sec Darks 10 x NB Flats & Dark Flats @ ADU 32,000
Location & Darkness
Fairvale Observatory – Redhill – Surrey – UK Typically Bortle 5 / 6
Date & Time
6th 7th 14th November 2023 + 15th January 2024 @ +21.00h
WATCH THIS SPACE(MAN) 