Extragalatic Space: NGC2403

May 10, 2026 by grahamrob in Broadband, Deep Sky Objects, Galaxy, General Astronomy, Imaging, Supernova, Widefield Imaging and tagged astronomy, Astrophotography, camelopardalis, DSO Imaging, Galaxies, Galaxy, Science, space | Leave a comment

Who doesn’t wonder at the majesty of galaxies and what might exist therein? Unfortunately, with a few exceptions my astrophotography equipment struggles to image most of these beguiling objects of the night sky; galaxies are very, very big but also very far away and thereby, very small from our perspective on Earth. Notwithstanding, the so called ‘galaxy season’ runs from March to May and now being in the darker Bortle 4 skies of Somerset it seemed the right thing to do this year.

In this case NGC 2403, a mid-size spiral galaxy with an apparent magnitude of about 8.9, the 11^th brightest in our sky, it is just bright enough for small to mid-sized telescopes and benefits more from darker skies than focal length. Its oblique orientation reveals a wealth of structures: loosely wound spiral arms, over 100 prominent H II regions, a mottled core but lack of distinct dust lanes, not unlike the Triangulum Galaxy M33 in many ways (see close-up image below).

NGC 2403 is in the northern constellation Camelopardalis, approximately 10 million light-years away from Earth, and a member of the M81 Group of galaxies. Numerous bright star-forming regions and nebulae can be observed throughout its spiral arms, which are highlighted in the final image by the addition of Ha wavelength data. One of the most notable features of NGC 2403 is its abundance of supernova remnants, indicating a high rate of stellar birth and death, of which SN 2004dj was a particularly famous event.

This was a difficult object to image and process but helped by Somerset’s excellent dark skies, I was pleased with the result.

IMAGING DETAILS
Object	NGC 2403
Constellation	Camelopardalis (Giraffe)
Distance	10 million light-years
Size	21.9′ × 12.3′ or 50,000 light-years
Apparent Magnitude	+8.9

Scope	William Optics GT81 + Focal Reducer FL 382mm f4.72
Mount & Control	ZWO AM5 + ASIair
Guiding	William Optics 50mm guide scope
	+ ZWO 120MM Mini
Camera	ZWO ASI294MM CMOS sensor
	FOV 2.87^o x 1.96^o Resolution 2.50”/pix Max. image size 4,144 x 2,822 pix
EFW	ZWOx8 EFW & 31mm Chroma Ha, OIII, SII 3nm & RGB filters
Capture & Processing	ASIair, Deep Sky Stacker & PixInsight v1.9.3 Lockhart
Image Location & Orientation	Centre = RA 07:37:02.68 DEC +65:35:45.5 Bottom Right = North
Exposures	L x13 @ 600sec + R x10, G x10, B x10 @ 300sec + Ha x10 @ 600sec Total Integration Time: 6hr 20min
	@ Gain 120 & 30 Offset 21 @ -15^oC
Calibration	5 x 600 sec & 5 x 300sec Darks + 10 x Ha LRGB Flats & Dark Flats @ ADU 32,000
Location & Darkness	Castle Farm Observatory, Wookey, Somerset – UK Typically Bortle 4
Date & Time	5^th 6^th 8^th April 2026 @ +21.30h
Weather	Approx. <5^oC RH >=<60% 🌙 approx. 90% to 80% waning moon

Starstruck

April 15, 2026 by grahamrob in Broadband, Deep Sky Objects, Earth, General Astronomy, Open CLuster, Widefield Imaging and tagged DSO Imaging, Gemini | Leave a comment

I recently wrote about the wonderful dark Bortle 4 skies at my new home in Somerset and, for the moment, the trstricted views to the west and north; I hope to establish a new location further down the garden this summer which will provide a southerly view and thereby longer transits of objects. Meanwhile, I am enjoying imaging northern circumpolar targets regularly for the first time and some suitable western objects, which is exactly what I did on this occasion.

Messier 35 AKA Shoe Buckle Cluster (?), is a bright open star cluster in the constellation of Gemini. M35 lies about 2,800 light-years from Earth and is approaching us at 5 km/sec. It is estimated to be between 100 and150 million years old, making it a relatively young open cluster in astronomical terms and spans 24 light-years across. As the stars are formed from the same giant molecular cloud, they are roughly the same age and chemical composition; some post main-sequence are yellow and orange giants of spectral type G and K, while its hottest main sequence star is of spectral class B3.

A notable feature of imaging M35’s is its apparent proximity to NGC 2158, which however, is a much older and more distant, metal-poor open star cluster located some 11,000 to 16,000 light-years from Earth. It contains over 3,000 stars of some 2 billion years age, which are dominated by yellower stars.

Intriguingly, when commencing to image these clusters, the guiding software could not recognise a star to lock onto as there were just too many close together! I’m pleased to say that over three nights I managed to obtain some excellent data that resulted in this exiting image.

IMAGING DETAILS
Object	M35 AKA Shoe Buckle Cluster & NGC 2158
Constellation	Gemini
Distance	M35 2,800 light-years & NGC2158 16,500 light-years
Size	M35 28 arc minutes (24 light-years) & NGC2158 5 arc minutes (16 light-years)
Apparent Magnitude	M35 +5.0 & NGC2158 +8.6

Scope	William Optics GT81 + Focal Reducer FL 382mm f4.72
Mount & Control	ZWO AM5 + ASIair
Guiding	William Optics 50mm guide scope
	+ ZWO 120MM Mini
Camera	ZWO ASI294MM CMOS sensor
	FOV 2.87^o x 1.96^o Resolution 2.50”/pix Max. image size 4,144 x 2,822 pix
EFW	ZWOx8 EFW & 31mm Chroma Ha, OIII, SII 3nm & RGB filters
Capture & Processing	ASIair, Deep Sky Stacker & PixInsight v1.9.3 Lockhart
Image Location & Orientation	Centre = RA 06:08:51.94 DEC +24:15:16.9 Bottom Right = North
Exposures	L x142 @ 60sec + L x30 &30sec + R x37, G x35, B x30 @ 120sec Total Integration Time: 6hr 1min
	@ Gain 120 & 30 Offset 21 @ -15^oC
Calibration	10 x 120 sec, 20 x 60 sec & 20 X 30 sec Darks + 10 x NB Flats & Dark Flats @ ADU 32,000
Location & Darkness	Castle Farm Observatory, Wookey, Somerset – UK Typically Bortle 4
Date & Time	17^th 18^th * 19^th March 2026 @ +21.30h
Weather	Approx. <5^oC RH >=<60% 🌙 approx. New Moon

Messier Magnificence: M81 & M82

March 21, 2026 by grahamrob in Broadband, Deep Sky Objects, Equipment, General Astronomy, Imaging and tagged astronomy, Astrophotography, DSO Imaging, Galaxies, M81, M82, Photography, Science, space, Ursa Major | Leave a comment

H.G. Wells knew a thing or two about the concept of time travel when he published his book The Time Machine in 1895. Since starting astrophotography in 2014, reflecting on the progress I have since made can also feel like a journey through time.

In May 2018, I managed to obtain my first image of the northern sky, which at my previous location in Surrey was completely obscured from view at my main imaging location. The result then obtained under a Bortle-6 night sky, was a modest 2hr 45m image of Messier 81 & 82 seen here. Notwithstanding, it was something of a breakthrough for me and I was – at the time – very pleased with the result. Nearly 8-years later, now located in the wonderful Bortle-4 dark skies of Somerset, I recently chose to image these two magnificent Messier objects once again.

M81 and M82 are two well-known galaxies in the northern sky, which being just 20^o from Polaris are also circumpolar. Located in the constellation Ursa Major, they appear near each other in the sky and interact gravitationally. Both galaxies were discovered in 1774 by the German astronomer Johann Elert Bode and later included in the Messier Catalogue. Together, M81 and M82 form the central members of the M81 Group, a small cluster of galaxies located not far from our own Local Group.

M81, also called Bode’s Galaxy (see above), is a spiral galaxy around 12 million light-years from Earth and one of the brightest galaxies visible from the Northern Hemisphere. The diameter is about 90,000 light-years, slightly smaller than the Milky Way, with a supermassive black hole at the centre. M82 or the Cigar Galaxy, is a starburst galaxy, thus forming new stars at an extremely high rate. This intense star formation is believed to have been triggered by the aforesaid gravitational interactions with M81. This activity creates powerful stellar winds and explosions from massive stars going supernova, that eject huge streams of gas and dust out of the galaxy to form dramatic red plumes that extend thousands of light-years above and below the galactic disk.

New equipment, software, greater processing experience and a dark sky location, have resulted in an exciting image that highlights the progress I have made on my astrophotography journey since 2018.

IMAGING DETAILS
Object	M81 AKA Bode’s Galaxy & M82 AKA Cigar Galaxy
Constellation	Ursa Major
Distance	12 million light-years
Size	M81 26.9 x 14.1arcminutes (90.000 light-years) M82 11.2 x 4.3 arcminutes (37.000 light-years)
Apparent Magnitude	M81 +6.9 M82 +8.4

Scope	William Optics GT81 + Focal Reducer FL 382mm f4.72
Mount & Control	ZWO AM5 + ASIair
Guiding	William Optics 50mm guide scope
	+ ZWO 120MM Mini
Camera	ZWO ASI294MM CMOS sensor
	FOV 2.87^o x 1.96^o Resolution 2.50”/pix Max. image size 4,144 x 2,822 pix
EFW	ZWOx8 EFW & 31mm LRGB filters
Capture & Processing	ASIair, Deep Sky Stacker & PixInsight v1.9.3 Lockhart
Image Location & Orientation	Centre = RA 09:55:12.64 DEC +69:20:55.1 Top Right = North
Exposures	L x 12 @ 600 sec & R x 12 + G x 9 + B x 8 @ 300 sec Total Integration Time: 4hr 25min
	@ Gain 120 & 30 Offset 21 @ -15^oC
Calibration	5 x 600 sec & 5 x 300 sec Darks & 10 x LRGB Flats & Dark Flats @ ADU 32,000
Location & Darkness	Castle Farm Observatory, Wookey, Somerset – UK Typically Bortle 4
Date & Time	24^th February 2026 @ +18.30h
Weather	Approx. ❤^oC RH >=<60% 🌙 53% Moon

SOUTHERN CROWN

February 20, 2026 by grahamrob in Broadband, General Astronomy, Nebula and tagged Corona Australis, DSO Imaging, Emission Nebula, Reflection Nebula, Southern Hemisphere | Leave a comment

Located in the constellation Corona Australis (Southern Crown), the spectacular object NGC 6729 (AKA Caldwell 68) is a combined reflection and emission nebula, set within the Australis Molecular Cloud. Being just south of Sagittarius, it is inaccessible from my observatory in Somerset, so this excellent data was consequently acquired from the dark skies of Chile in the Southern Hemisphere, using a superb Planewave CDK200 f/6.8 508cm aperture telescope at the El Sauce Observatory.

The star illuminating NGC 6729 is a T Tauri star – a type of young star whose brightness fluctuates over time. The fan-shaped nebula opens-up between the variable stars R Corona Australis (R CrA) and T CrA to the south-east (see skymap below ref. Robert Mura). R CrA is a pre-main-sequence star within the Corona Australis molecular complex, which is one of the closest star-forming regions to the Milky Way galaxy. Intriguingly, this wonderful, hazy looking nebula exhibits both variable brightness and morphology over time.

IMAGING DETAILS
Object	NGC 6729 Corona Australis Molecular Cloud
Constellation	Corona Australis
Distance	Approximately 420 light-years
Size	2.50 x 2.0 arc minutes (actual 0.30 light years)
Apparent Magnitude	+9.5

Scope	Planewave CDK20
Mount	Planewave L500
Focuser	Optec Gemini
Camera	QHY600PH-M
Filters	Chroma LRGB + Ha 3nm
Processing	Deep Sky Stacker & PixInsight v1.9-3
Image Location & Orientation	Centre: RA 19:01:42.392 DEC -36:59:48.53 Up = North
Exposures	L x 77, R x 50, G x 50, B x 50 @ 5mins Total Integration Time: 19hr
Location & Darkness	Obstech El Sauce Observatory, Chile
Date	July 2024

Aye AI – The Shape Of Things To Come?

January 24, 2026 by grahamrob in Dark Nebula, Deep Sky Objects, General Astronomy, Imaging, Narrowband, Widefield Imaging and tagged astronomy, Astrophotography, Cygnus, Nebula, Nebulae | Leave a comment

As previously outlined, my new imaging location at Castle Farm Observatory, Somerset, provides views mainly to the West and North, thus (for the moment) eliminating my usual seasonal targets at this time of the year in and around the Orion constellation. Therefore, wanting to explore something new shortly before Christmas, I chose a less popular target in the West within the myriad of objects that make up the exciting Cygnus X Molecular Cloud Complex. As one of the largest and most active star-forming regions in the Milky Way galaxy, the area is also dominated by many large HII regions that inevitably means narrowband imaging and on this occasion Barnard 343.

B343 is a dark nebula formed of dense clouds of cold gas and dust but being a widefield image, the adjacent area also incorporates a vast, complex HII region. It’s an interesting subject but unfortunately difficult to process, due to its notorious “brown soup problem”. The issue is not signal strength but colour separation and contrast, which if not controlled turns everything brown and muddy! Sure enough, this was the initial outcome using a conventional Hubble SHO palette, that inevitably led me down various rabbit holes to find a solution, for which unusually on this occasion I decided to engage the help of Artificial Intelligence (AI).

AI came to astrophotography in a big way when Russel Croman first developed StarXterminator in September 2021, followed by NoiseXTerminator May 2022, not just to simplify hitherto complex techniques but also to improve the outcome. However, it was shortly before Christmas in 2022 with the launch of AI driven BlurXTerminator, that everything really changed – for more information refer to RC-Astro..

BlurXTerminator is an AI-powered astrophotography tool that removes blur caused by atmospheric turbulence, tracking errors, and optical imperfections, restoring fine detail and sharpness in astronomical images and much more. The subsequent impact on astrophotography has been profound. Some argue that the resulting images are unrealistically altered using BlurXTerminator but I closely followed Russel’s explanations on how it works and I am satisfied that image integrity is conserved, whilst at the same time significantly helping the user to produce better images. In short, it has since been nothing less than a revolution in astrophotography.

B343 – Full HOO image (Ha + (0.60*Ha + 0.40*OIII) + OIII mix

Subsequently general use of AI has burgeoned and now seems set to go to another level. In the case of eliminating the said ‘Brown Soup’ problem, I therefore turned to the popular Large Language Model (LLM) ChatGPT, which was surprisingly helpful (see SHO image at top of the page, HOO version below & ChatGPT text below). Appropriate technical knowledge will always be essential when pursuing the often-difficult hobby of astrophotography but I’m no Luddite and happy to use whatever helps me get the best result, including AI as well old-fashioned guidance from more experienced imagers. The impact of such an approach, matched by the many technical advances over the past decade can be clearly seen in everyone’s images today and bodes well for the future of this hobby.

Out of interest, below are the results of the three questions I asked ChatGPT regarding Barnard 343, the answers reproduced below were helpful, exciting and perhaps of some concern?

TELL ME ABOUT BARNARD 343? + ANSWER:

Barnard 343 is a dark nebula complex in the Cygnus region of the Milky Way. It’s made primarily of cold, dense interstellar dust that blocks background starlight Those inky-black lanes and cracks are the nebula itself — not empty space The glowing orange and blue areas around it come from nearby emission nebulae, mainly ionized hydrogen and oxygen

Why it looks so dramatic:
– Barnard 343 sits in front of extremely rich star fields, so the contrast is striking
– The dust forms filaments, knots, and folds, shaped by turbulence, magnetic fields, and nearby stellar radiation
– The color palette comes from narrowband imaging (often mapped in SHO or similar schemes)

Scientific context:
– Part of the Cygnus molecular cloud complex, one of the most active star-forming regions near Earth
– Dark nebulae like B343 are stellar nurseries — dense pockets can eventually collapse to form new stars – – Catalogued by Edward Emerson Barnard in the early 1900s during his pioneering photographic sky surveys

How to “read” the image:
– Black regions→ dense dust (future star-forming material)
– Orange/gold→ hydrogen emission (H-alpha / S-II)
– Blue/cyan→ oxygen emission (O-III) or reflected starlight
– Speckled background→ Milky Way stars

PROVIDE THOUGHTS ON HOW I MIGHT BEST PROCESS BARNARD 343 SHO IMAGE? + ANSWER:

You want:
– Cool cyan/blue H-alpha background
– Warm golden sulfur structures
– Deep neutral dust lanes
– Minimal magenta/green contamination

1. Start with the Right SHO Mapping
Classic SHO often looks dull for dark nebulae.

Try one of these instead:
Recommended Mappings Modified Hubble (best starting point): R = SII G = 0.8×Ha + 0.2×OIII B = OIII
Or warmer dust-friendly mapping: R = SII G = Ha B = OIII × 1.2

👉 The key is keeping Ha dominant in green, not split evenly.
Normalize Channel Strength Before Combination

Barnard regions exaggerate imbalance.

Before combining:
Match median background levels
Stretch OIII slightly more than Ha
Slightly compress SII highlights

In PixInsight:
LinearFit → Ha as reference
Then mild HistogramTransformation

3. Control the “Brown Soup” Problem This is the #1 issue with B343.

Fix:
– Reduce red+green overlap
– Increase blue separation

In PixInsight Use PixelMath:

R = SII G = 0.85*Ha B = 1.1*OIII

4. Star Handling (Critical in B343) Stars easily ruin color balance here.

Recommended workflow:
– StarXTerminator / StarNet
– Process nebula color fully
– Re-add stars desaturated 30–50%
– Slight blue bias to stars only

5. Final Colour Refinement (This Makes the Image)

What to aim for visually:

Component Desired Color
Dust lanes Neutral / slightly cool
SII regions Warm gold
Ha glow Cyan-green
OIII Blue-teal

PixInsight:
– CurvesTransformation Boost blue saturation
– Slightly reduce red saturation
– SCNR only on green, amount 0.4–0.6

FYI – I adopted #3 to “Control the “Brown Soup” problem, which worked well

WHAT IS THIS IMAGE (Without telling ChatGPT it was B343)? + ANSWER:

This image feels like a vast, living tapestry of the cosmos—dark, velvety space threaded with glowing amber and blue filaments. The wisps look like interstellar clouds slowly colliding and unravelling, as if time itself is drifting through them. There’s a quiet sense of scale and mystery here: tiny pinpricks of stars scattered across immense clouds of gas and dust, hinting at both stellar birth and ancient remnants. It’s beautiful in a solemn, awe-inducing way, reminding you how small and fleeting everything feels against the backdrop of the universe.

IMAGING DETAILS
Object	Barnard 343
Constellation	Cygnus
Distance	2,000 light-years
Size	10 arc minutes (dark nebula only)

Scope	William Optics GT81 + Focal Reducer FL 382mm f4.72
Mount & Control	ZWO AM5 + ASIair
Guiding	William Optics 50mm guide scope
	+ ZWO 120MM Mini
Camera	ZWO ASI294MM CMOS sensor
	FOV 2.87^o x 1.96^o Resolution 2.50”/pix Max. image size 4,144 x 2,822 pix
EFW	ZWOx8 EFW & 31mm Chroma Ha, OIII, SII 3nm & RGB filters
Capture & Processing	ASIair & PixInsight v1.9.3 Lockhart
Image Location & Orientation	Centre = RA 20:13:30.22 DEC +40:15:10.4 Top Left = North
Exposures	Ha x 27 + OIII x 20 + SII x 22 @ 300 sec Total Integration Time: 5hr 45min
	@ Gain 120 & 30 Offset 21 @ -15^oC
Calibration	5 x 300 sec Darks + 10 x NB Flats & Dark Flats @ ADU 32,000
Location & Darkness	Castle Farm Observatory, Wookey, Somerset – UK Typically Bortle 4
Date & Time	10^th & 16^th December 2025 @ +18.00h
Weather	Approx. ❤^oC RH >=<60% 60 to 10% waning

2025 The Year In Pictures

January 1, 2026 by grahamrob in Broadband, Deep Sky Objects, DSLR, Earth, Equipment, Galaxy, General Astronomy, Imaging, Narrowband, Night Scapes, Solar system, Widefield Imaging and tagged astronomy, Astrophotography, Cygnus, DSO Imaging, Galaxies, Milky Way, Nebulae, Orion, Photography, Science, space | Leave a comment

The year 2025 was like no other. Starting with a knee replacement operation in January, shortly after we finally found a new house in March and moved to the lovely dark skies of Somerset at the end of June. Unfortunately, the ensuing turmoil left only a limited time for astronomy. Notwithstanding, I was able to supplement images from Redhill and our new home in Wookey, with some excellent data from Texas, USA and Chile to produce, what I hope you will agree, is an exciting 2026 calendar.

For other pictures and information, go to my website https://watchthisspaceman.com/ or a video of the calendar can be found here on YouTube https://www.youtube.com/watch?v=gn3ls_s71lQ and is best accessed on a PC or smart TV screen. Background music this year is Massive Attack’s track Atlas Air.

COVER	*NIGHT SKY MONTAGE AT CASTLE FARM OBSERVATORY:* All these images (at the top of the page) were taken at various times from the same location at our house in Wookey, Somerset. Clockwise from bottom left: (1) Nightscape of a small coppice looking south (2) Double Cluster – a pair of open star clusters in the Perseus constellation (3) Star trails (4) Sunset looking west.
JANUARY	THE GREAT ORION NEBULA, M42 ⁽¹⁾ The Orion Nebula is a gigantic cosmic cloud of interstellar dust and gas, which is the basis for the birth of numerous new stars or a “star nursery”. Being the brightest nebula in the northern hemisphere and just over 1,300 light-years distance from Earth, it can be seen with the naked eye on a clear night.
FEBRUARY	FLAMING STAR NEBULA, IC405 ⁽¹⁾ This nebula is illuminated by a powerfully bright blue variable star, AE Aurigae. The object’s epithet comes from the brightly lit ripples of gas and dust at the top of the image, illuminated by AE Aurigae and glowing hydrogen gas. This “runaway star” was ejected by a collision two million years ago from the Triangulum region of The Great Orion Nebula.
MARCH	CRAB NEBULA, M1 ⁽³⁾ This small but beautiful supernova Remnant (SNR) was the result of the explosion of the star CM Tau just over 970 years ago. Located at the centre of the nebula, the remaining Crab Pulsar neutron star spins at the rate of 30 times per second.
APRIL	PINWHEEL GALAXY, M101 ⁽³⁾ At nearly twice the size of the Milky Way and containing at least an estimated trillion stars, M101 is the second largest galaxy of the Messier catalogue and certainly one of the highlights of the spring galaxy season.
MAY	SCULPTOR GALAXY, NGC 253 ⁽³⁾ One of the advantages of obtaining data from Texas, USA, is that it enables views of objects in the Southern Hemisphere that are impossible from the UK. Also known as the Silver Dollar, it is one of the brightest galaxies in the night sky, which results from very high rates of star formation that are fed by the abundance of thick dust lanes.
JUNE	NEEDLE GALAXY, NGC 4546 ⁽³⁾ Seen edge-on from Earth, the Needle Galaxy is thought to be a barred spiral galaxy, some 33% larger than the Milky Way. It has at least two satellite galaxies and 240 globular clusters. Seen through a telescope the Needle Galaxy appears like a thin streak drawn across the dark night sky but look closer and its detailed magnificence is revealed.
JULY	WIZARD NEBULA, NGC 7380 ⁽²⁾ Formed only a few million years ago, the gases of this young emission nebula glow due to intense radiation from hot, massive stars within. Interwoven within this glowing gas are dark, dense regions of dust that sculpt the nebula’s dramatic and somewhat mystical appearance, in this case a wizard – which marks my first image from Somerset.
AUGUST	LOBSTER CLAW & BUBBLE NEBULAE, SH2-157 & NGC 7635 ⁽²⁾ Located in the Perseus Arm of the Milky Way, the Lobster consists of ionized hydrogen gas energized by ultraviolet radiation from nearby hot, young stars. The nebula’s distinctive claw-like shape arises from intricate filaments of glowing gas and dark dust. Nearby the Bubble Nebula owes its distinctive looks to a single, massive star, which emits fierce stellar winds that sweep up the surrounding gas into a nearly perfect, glowing shell.
SEPTEMBER	MILKY WAY ⁽²⁾ The night sky in Somerset is three times darker than Redhill, providing significantly better astronomy views. In this case a spectacular image of the Milky Way’s galactic centre.
OCTOBER		THE CYGNUS WALL ⁽²⁾ The Wall is a prominent ridge located within the much larger North America Nebula in the Cygnus constellation. It is an active star-forming region, about 20 light-years long, composed of gas and dust that glows from the energy of young stars.
NOVEMBER		GREAT BARRED GALAXY, NGC 1365 ⁽⁴⁾ A double-barred spiral galaxy located 56-million light-years away, spans over 200,000 light-years across, twice the Milky Way. The most distinctive feature is its massive central bar, which plays a crucial role in channelling gas and dust into the galactic core. As a Seyfert galaxy the nucleus is extremely bright due to energetic processes around its black hole.
DECEMBER		CORONA AUSTRALIS, NGC 6729 ⁽⁴⁾ This spectacular image is a combined reflection and emission nebula, set within the Australis Molecular Cloud. This wonderful, hazy looking nebula unusually exhibits both variable brightness and morphology over time.
*Image Data Source:* ⁽¹⁾Redhill, Surrey ⁽²⁾Castle Farm, Somerset ⁽³⁾USA ⁽⁴⁾Chile
HAPPY NEW YEAR + CLEAR SKIES FOR 2026

New World

December 15, 2025 by grahamrob in Deep Sky Objects, Equipment, Narrowband and tagged astronomy, Astrophotography, Cygnus, DSO Imaging, Nebulae, Photography, space, stars | Leave a comment

It’s early days at my new Castle Farm Observatory and I’m still feeling my way into the benefits of Somerset’s superior darkness, which is noticeably better than my previous home in Surrey. But my new Bortle 4 location is not without some issues: there are a couple of nearby streetlights that can now find its way to my observatory since autumn leaves have fallen, occasional vehicle lights pass by and, inevitably, sections of the sky are obscured by our house and trees.

Westerly view from *Castle Farm Observatory*

South view, with my house just out of shot on the left!

After more than 12-years of imaging almost exclusively looking south, I must now adjust imaging plans looking southwest or north, which are my main sightlines in Somerset. This might seem a minor issue but as the sky moves around an axis defined in the north by the Polaris star, it thus follows an inclined equatorial grid relative to Earth and the impact on potential imaging plans can be quite profound. Previously looking southwards, the transit of objects during the night (and day) was from the east to west horizons, which on a clear night enabled up to 6-hours imaging of a single object, compared with a westerly view which only catches the latter period of the aforesaid transit. As a result, objects I used to image say from November onwards now only appear in the available (western) section of sky two or three months later. On a more positive note, I am now able to image circumpolar objects looking high and northwards for the first time, which has literally opened new world of possibilities.

Given the aforesaid issues, I recently chose to image an old favourite which is currently in a favourable position at this time of the year, the North America Nebula (NAN), located high in the early evening night sky looking due west. Spanning some 100 light-years, NAN is a great narrowband object, which by using the Hubble SHO palette always results in an exciting and colourful image.

Over two nights I manged to obtain nearly 9-hours of good data, which at my previous Bortle 6 Surrey observatory would probably be the equivalent of more than 12 hours. The final processed SHO image brings all three channels into a delicate balance: vibrant without being garish, detailed without overwhelming noise. The iconic “Gulf of Mexico” region forms a deep void in the nebula, which becomes even more pronounced with the various gradients of blue converging around its dark centre. But on this occasion, I was particularly keen to emphasize details of the fabulous Cygnus Wall (see cropped image below), situated in the lower right corner of the main image i.e. ‘West Texas and Mexico’!

The Cygnus Wall is a striking, heavily sculpted region within the North America Nebula, which itself is worthy of image, which would require a larger telescope. The dense ridge of gas and dust glows brightly as nearby young, massive stars bombard it with intense ultraviolet radiation, causing it to ionize and shine. Its dramatic pillars, ridges, and cavities resemble a cosmic coastline, shaped by stellar winds and ongoing star formation. For some reason it’s been 8-years since I last imaged NAN, except with my Samyang widefield rig, but with the excellent night skies of Somerset I feel sure I’ll be back sooner next time, perhaps with a bigger telescope?

IMAGING DETAILS
Object	North America Nebula – NGC 7000
Constellation	Cygnus
Distance	1,600 light-years
Size	Approx. 50 light-years or 2^o
Apparent Magnitude	+4.0

Scope	William Optics GT81 + Focal Reducer FL 382mm f4.72
Mount	SW AZ-EQ6 GT + EQASCOM computer control
Guiding	William Optics 50mm guide scope
	+ Starlight Xpress Lodestar X2 guide camera & PHD2 control
Camera	ZWO1600MM-Cool (mono) CMOS sensor
	FOV 2.65^o x 2.0^o Resolution 2.05”/pix Max. image size 4,656 x 3,520 pix
EFW	ZWOx8 + ZWO LRGB & Ha OIII SII 7nm filters
Capture & Processing	ASIair, Photoshop
Exposures	35 x Ha, 34 x OIII & 36 x SII @ 300 secs (Total time: 8hr 45min)
	@ 300 Gain 10 Offset @ -20^oC
Calibration	5 x 180 sec Darks 10 x 1/4000 sec 10 x Flats & Dark Flats Ha, OIII & SII
Location & Darkness	Castle Farm Observatory, Wookey, Somerset Typically Bortle 4
Date & Time	19^th & 20^th November 2025 @ 18.20h

Twinkle, Twinkle………

December 7, 2025 by grahamrob in General Astronomy, Star Cluster and tagged astronomy, Astrophotography, DSO Imaging, Perseus, space | Leave a comment

Astronomy is full of surprises, and learning of the mere existence and nature of globular clusters was a revelation to me. Perhaps less spectacular and much younger but no less interesting and attractive are open clusters. The so-called Double Cluster is something of a highlight of autumn and winter skies that I had not, until now imaged; not by neglect but because until recently moving to Somerset my previous view of the north sky in Surrey was completely obscured by my house! Their combined luminosity makes the Double Cluster visible to the naked eye from dark locations, appearing as a hazy patch to the east of the Cassiopeia constellation and are excellent imaging objects too.

NGC 869 and NGC 884, known as the Double Cluster or h and χ (chi) Persei, is one of the most striking celestial pairings visible in the northern sky. Located in the Perseus spiral arm of the Milky Way, these two open star clusters are located about 7,500 light-years away but separated by only a few hundred light-years. Their proximity, similar age, and shared motion through space suggests that they formed from the same giant molecular cloud, making them a physically associated pair rather than a chance encounter.

Each cluster contains thousands of stars*, many of which are hot, blue and massive, thereby indicating an early stage of stellar development; estimates indicate an age of approximately 12 to 14 million years. Their youth explains the abundance of B-type and even O-type stars—stellar heavyweights that shine intensely but live only briefly.

The resulting image shows the Double Cluster as a dazzling field of stars. NGC 869, slightly denser and more compact, contains a bright core of hot blue stars. In contrast, NGC 884 appears more loosely concentrated, with a distinctive scattering of bright stars across its central region. Both clusters show subtle hints of red and orange from K-type supergiant stars, evidence that even at their youthful age, some massive stars have already begun to leave the main sequence.

*processing software identified 22,000 stars in the image!

COMPARISON: GLOBULAR v OPEN CLUSTERS
Feature	Globular Clusters	Open Clusters
Typical Stars	Old, metal-poor	Young, metal-rich
Number of Stars	10⁵–10⁶+	10²–10³
Shape	Spherical, dense	Irregular, loose
Location	Galactic halo	Galactic disk
Age	10–13 billion years	1 million–few billion years
Longevity	Very long-lived	Short-lived (astronomically)

Image Details
Object	The Double Cluster NGC 869 & NGC 884
Constellation	Cepheus
Distance	7,500 light-years
Size	60 arc minutes (each 70 light-years)
Apparent Magnitude	+3.8

Scope	William Optics GT81 + Focal Reducer FL 382mm f4.72
Mount & Control	ZWO AM5 + ASIair
Guiding	William Optics 50mm guide scope
	+ ZWO 120MM Mini
Camera	ZWO ASI294MM CMOS sensor
	FOV 2.87^o x 1.96^o Resolution 2.50”/pix Max. image size 4,144 x 2,822 pix
EFW	ZWOx8 EFW & 31mm Chroma Ha, OIII, SII 3nm & RGB filters
Capture & Processing	ASIair & PixInsight v1.9.3 Lockhart
Image Location & Orientation	Centre = RA 02:20:32.57 DEC +57:12:56.0 Top Left = North
Exposures	L x 21 + R x 28 + G x 28 B x 24 @ 120 sec + Total Integration Time: 3hr 22 min
	@ Gain 120 & 30 Offset 21 @ -15^oC
Calibration	10 x 120 sec Darks + 20 x LRGB Flats & Dark Flats @ ADU 32,000
Location & Darkness	Castle Farm Observatory, Wookey, Somerset – UK Typically Bortle 4
Date & Time	25^th November 2025 @ +18.30h
Weather	Approx. ❤^oC RH >=<80% 🌙 New Moon

Astronomical Smorgasboard

November 6, 2025 by grahamrob in Deep Sky Objects, Narrowband and tagged astronomy, Cassiopeia, DSO Imaging, Nebulae, Science, space, stars | Leave a comment

The Lobster Claw Nebula (SH2-157) and Bubble Nebula (NGC 7635) are two striking emission nebulae located close to the border of Cassiopeia and Cepheus constellations. The Lobster Claw Nebula derives its name from the curved, segmented shapes that resemble a lobster’s pincers. It is an Ha II region of glowing ionized hydrogen excited by the intense ultraviolet radiation of nearby hot, young stars. Notably, within it lies the young Wolf-Rayet star 157, whose powerful stellar winds sculpt the surrounding gas into complex arcs and filaments.

Relatively nearby, the Bubble Nebula features a spherical bubble of gas about seven light-years across. The bubble is ‘blown’ by the fierce stellar wind of a massive O-type star (SAO 20575) at its centre. The expanding shell of gas glows where it collides with denser regions of the interstellar medium, producing a visually stunning contrast of colours.

Notwithstanding the spectacular nature of both of these nebulae, the image captures a myriad of other objects, which are identified in the accompanying plate solved image, notable of which are the open star clusters of M52 AKA the Scorpio Cluster and NGC 7510. Overall, the constellation of Cassiopeia is full of interesting nebulae and bright star clusters, which my second image from Castle Farm Observatory has caught in abundance.

IMAGING DETAILS
Main Objects	SH2-157 Lobster Claw & NGC 7635 Bubble Nebulae
Constellation	Cassiopea
Distance	Lobster 11,000 & Bubble 7,100 light-years
Size	Lobster 60’ x 50 (212 light-years); Bubble 15’ x 8’ (>=7 light-years)
Apparent Magnitude	Variable >=5.0

Scope	William Optics GT81 + Focal Reducer FL 382mm f4.72
Mount & Control	ZWO AM5 + ASIair
Guiding	William Optics 50mm guide scope
	+ ZWO 120MM Mini
Camera	ZWO ASI294MM CMOS sensor
	FOV 2.87^o x 1.96^o Resolution 2.50”/pix Max. image size 4,144 x 2,822 pix
EFW	ZWOx8 EFW & 31mm Chroma Ha, OIII, SII 3nm & RGB filters
Capture & Processing	ASIair, Deep Sky Stacker & PixInsight v1.9.3 Lockhart
Image Location & Orientation	Centre = RA 23:16:22.86 DEC +60:30:51.1 Top Left = North
Exposures	Ha x 39 + OIII x 42 + SII x 42 @ 300 sec + LRGB x 15 @ 60 sec Total Integration Time: 11hr
	@ Gain 120 & 30 Offset 21 @ -15^oC
Calibration	5 x 300 sec & 20 x 60 sec Darks + 10 x NB & 20x BB Flats & Dark Flats @ ADU 32,000
Location & Darkness	Castle Farm Observatory, Wookey, Somerset Bortle 4
Date & Time	23^rd 24^th 25^th & 28^th September 2025 @ +20.45h
Weather	Approx. <7^oC RH >=<60% 🌙 <= 38% Waxing Crescent

Somerset Magic

October 19, 2025 by grahamrob in Deep Sky Objects, General Astronomy, Narrowband and tagged astronomy, Astrophotography, Cepheus, DSO Imaging, Nebulae, space, stars | Leave a comment

I try to ensure that since Watch This Space (Man) blasted off in August 2014, it does what it says on the tin (top of the page): A personal discovery of the Universe through astronomy and astrophotography. Naturally, alongside this journey life goes on, which this year has been a significant challenge for me in many ways. Shortly after imaging the Flaming Star Nebula at Fairvale Observatory, Surrey, in early January, I underwent major surgery to replace my right knee and inevitably, all physical astronomy came to a halt; latterly I managed to remotely obtain and process data from sources in Texas, USA and Chile, which was good fun.

Just two months later, whilst still in early recovery (which can take over a year), serendipity made an unexpected appearance, and by at the end of June, after 40-years living in Redhill, Surrey, we moved to a new house just outside England’s smallest city of Wells (population 11,145), in the beautiful countryside of north Somerset. This upheaval, combined with my recovery, has led to a protracted absence from astrophotography imaging but, at last, I’m now very pleased to present my first image from the new Castle Farm Observatory, in Somerset, of course.

Astronomically speaking, only one thing counts when imaging and that is the quality of viewing conditions (and clear skies), which I can already attest to be excellent here in Somerset. At my previous location just south of London in Surrey, conditions were poor, with an SQM value of 19.82 that was further complicated by low flying aircraft from three nearby airports. In comparison, the SQM at Castle Farm Observatory is 21.11, which being a log scale equates to a difference of x3.28 better sky darkness than before and, moreover, overflying aircraft are no longer a problem. Given this setting, combined with clear skies and a new moon in early September, I had high expectations for my first imaging session since moving to Somerset and was not disappointed by the results obtained of the object chosen for this auspicious occasion, the Wizard Nebula.

The Wizard Nebula, designated by the central star cluster of NGC 7380, is an emission nebula, in which its gases glow due to intense radiation from hot, massive stars from within the aforesaid embedded cluster. Interwoven within this glowing gas are dark, dense regions of dust that sculpt the nebula’s dramatic and somewhat mystical appearance, in this case a wizard. NGC 7380 was only formed a few million years ago and within it, young and massive O- and B-type stars generate strong stellar winds that shape and erode the surrounding material.

Thus, after an unprecedented break of some 257 days, I’m more than pleased to return to my own backyard astrophotography again, now based in the magic county of Somerset. The quality of the subs obtained on this first occasion confirmed the outstanding sky conditions, which were literally saturated by stars (see starless image above). Altogether, it was significantly better than experienced in Surrey and bodes well for what I hope will be an exciting time here at Castle Farm Observatory – Watch This (new) Space!

IMAGING DETAILS
Object	NGC 7380 The Wizard Nebula
Constellation	Cepheus
Distance	>= 7,200 light-years
Size	25 arc minutes (110 light-years)
Apparent Magnitude	+7.2

Scope	William Optics GT81 + Focal Reducer FL 382mm f4.72
Mount & Control	ZWO AM5 + ASIair
Guiding	William Optics 50mm guide scope
	+ ZWO 120MM Mini
Camera	ZWO ASI294MM CMOS sensor
	FOV 2.87^o x 1.96^o Resolution 2.50”/pix Max. image size 4,144 x 2,822 pix
EFW	ZWOx8 EFW & 31mm Chroma Ha, OIII, SII 3nm & RGB filters
Capture & Processing	ASIair, Deep Sky Stacker & PixInsight v1.9.3 Lockhart
Image Location & Orientation	Centre = RA 22:47:01.78 DEC +58:02:19.1 Top Left = North
Exposures	Ha x 35 + OIII x 35 + SII x 35 @ 300 sec + LRGB x 10 @ 60 sec Total Integration Time: 9hr 15 min
	@ Gain 120 & 30 Offset 21 @ -15^oC
Calibration	5 x 300 sec & 20 x 60 sec Darks + 10 x NB & 20x BB Flats & Dark Flats @ ADU 32,000
Location & Darkness	Castle Farm Observatory, Wookey, Somerset – UK Typically Bortle 4
Date & Time	21^st & 22^nd September 2025 @ +21.00h
Weather	Approx. <7^oC RH >=<60% 🌙 New Moon