Author Archives: Rob Leonard

The Ghost of Cassiopeia

This is my first full colour picture from a mono camera 🙂

This nebula sits next to Navi in Cassiopeia (Gamma Cass)- apparently the star is gradually eroding the nebula. The nebula itself is both an emission and a reflection nebula, but I think I’ve only managed to capture the emission parts here.

I took this over 2 nights on 15th and 17th Jan. It’s been a bit of a learning process to put this together:

  • 40 mins of 2 minute subs in each of LRGB on 15th
  • 100 mins of 5 minute subs in Ha on 17th

It certainly takes a bit more effort to process mono, and it wasn’t helped by loads of problems with ice and fogging on my secondary. This led to not getting much Ha signal, and I’ve used layers in Gimp to bring it out (don’t tell Pixinsight- they’ll excommunicate me!). I think there’s probably more can be extracted from this data- especially around the body of the nebula- but I’m still pleased to have a full colour image!

I had another go at this a few days later and the whole scope completely iced up- see picture at the bottom!

 

 

Winter Widefield

Here are a couple from last week. First up, here’s a widefield view of the Milky Way- taken at 18mm on my 18-55 zoom. I did one of these about 4 months ago- it’s nice to catch the ‘next bit’ of the galaxy so to speak. This is an hours worth of 60 second exposures.

With hindsight I think I’d have been better off stopping it down a bit (this was f3) and going for, say, 30 2 minute exposures, as it was a swine to focus and the star shapes at the edges of the frame are more like fans. Still- it’s been nice to work my way around the frame and pick out some familiar objects- here’s an annotated version below:

A bit more successful was this slightly tighter view taken with the 50mm lens on the 15th when Neil came over and was working on his rather splendid Rosette. Again- this was an hours worth of 60 second exposures at f3.5, but the lens made a better job of keeping things sharp(ish).

The plan on this one was to be looking out past the edge of our galaxy at Andromeda (coming to get us!), but I haven’t been able to pick up of a drop off in the star density to pick up the edge of the galaxy. I might try this one again one day from a darker site. I still like this image a little better than the wider one as the objects in it are a bit more distinct- Pacman is really clear, Caroline’s Rose is quite prominent and you can see the dark nebulae of our galaxy.

 

Worth waiting for…

It’s been a bit of a barren few months for observing- bits and pieces here and there, but no really good session to get properly stuck in.

The forecast for last night was looking great all through the week but gradually deteriorated as it drew closer and was looking decidedly iffy by the time last night arrived. There were a few breaks in the cloud so I decided to set up just before ten (hey- no work today! 😀 ). This was soon looking decidedly optimistic:

First stint:

  • M42 – really nice view at 55x with UHC filter- well able to distinguish the fainter nebulosity behind as well as the bright core. Despite upping the mag, however, the trap would not reveal any more than 4 stars.
  • M43 and Running Man also looking really good. Until they disappeared. Yep, clouds.

Swung the scope round to a clearer bit of sky near Ursa Major:

  • M81 – Nice view of the core, but little extension beyond. First view for a while- nice to see this pair rising again after hugging the evening horizon for the last few months.
  • M82- A better sight- some distinct mottling along it and thickening at the core. Then the clouds got it.

There’s a gap!

  • Nice split on Castor
  • NGC2371 – Planetary Nebula – I don’t know this one. Quite faint. It really blinks. Oh- it’s gone.

Blow this- headed inside for a drink and some cursing of UK weather. Kept checking with gradually diminishing enthusiasm every 20 minutes or so. One last look at 12:15- Wow- crystal clear! Right…

  • Cone nebula – this was my imaging target for the night so I thought I’d have a look. The Christmas tree cluster was nice and pretty, but after letting my eyes relax and adapt the nebulosity emerged. This is the best view I’ve ever had of this object. Now we’re talking!
  • Dropped down to the Rosette- same experience. I’ve only seen hints of this before, but whilst the overall shape was hard to discern (it was filling the 30mm FOV) the central cluster was nice and prominent and by holding it centrally and just looking round the view lots of wispy structure gradually emerged. I spent a while on this. Really nice.
  • Next I thought I’d have a look at Sirius and see if the Pup was visible, despite being just above my neighbours house. Upping the magnification and putting the aperture mask on it was… dancing like a disco glitterball. No chance!
  • Leo Triplet. Leo was now rising high over the rooftops so I took my first view of the season at the triplet. It was really nice and prominent in the 30mm, but the best view was in the Baader zoom where a bit more shape was discernible. Even NGC 3628 was easy to spot- good conditions indeed.
  • C/2017 T2 Panstarrs Comet – This took a lot of finding- very careful star hopping in the ep from Miram on the edge of Perseus. In Sky Safari it looks like you can follow the tail, but for me only the head was visible and this was a pretty faint smudge, jumping several fields of view across to find it and working with star patterns.
  • From here it was a short hop to the Double Cluster- always such a good sight. By now this was well over to the North West, but this is a good direction for me and the view was lovely and steady with lots of the stars yielding plenty of colour- a wonderful sight.
  • I thought from here I’d go and look at the Heart Nebula, but took a slightly wrong turn and found the Stock 2 Open Cluster instead. This is a new one on me, but was a nice rich view, filling more than the eyepiece at 30mm.
  • The Heart was a bit fainter than the Rosette and Cone, but I could still see the bright section around the central open cluster.
  • The Soul was brighter- the nebulosity was more prominent- especially around the ‘neck’ and ‘feet’ bits.
  • This was fast turning into my best ever night for nebulae, and to keep it going I moved up to Capella to try for the Flaming Star. Very pleasingly, not only was it clearly visible, but I could make out the rippling texture along the top edge of it.
  • Feeling like I was on a roll I moved across to the ‘Tadpoles’ nebula (surely it should be called this?) next to it. This didn’t show any texture, but some wisps were definitely visible.
  • I’m really fond of the clusters in Auriga so I took the 30mm out and did a nice tour of M36, M37 and M38 with the Baader zoom.
  • It was getting on for 3 now and really time for bed but with Ursa Major rising high in the sky I couldn’t resist a quick look at M51. Both cores were quite prominent and the bridge between them too, but I couldn’t get much further into the arms on this occassion.

I’ve had the scope out a few times over the last few months and a few nice views, but for various reasons it hasn’t really come together into a properly decent session like this. There were some fabulous views and it was enhanced by some virtual companionship on the WhatsApp group. The thing that has me scratching my head is why the views of the nebulae were so good. I’ve been using the same equipment for a while now (14inch dob, 30mm Aero Eyepiece and UHC filter) but it’s never been close to this despite some apparently excellent transparency and sessions at darker sites. I guess just another reminder of what a capricious pursuit this is!

Heart and Soul

Finally had a chance to catch up with some processing this weekend.

Firstly- here’s a widefield shot including the Soul nebula and the Double Cluster from 4th December. This is taken from the best 70% of two hours of data using vintage 135mm lenski on a 600d and Star Adventurer, with the usual set of calibration frames.

Next up here’s a Ha and Oiii from 1st December on the Heart. This is from 14×10 mins of Oiii and 30x 10 minutes of Ha. I should have done them the other way around as the Ha is a stronger signal, but I had the Oiii in to start with. I’ve used an “HOO” palette for this- feeding the Ha into the Red and then the Oiii into both Blue and Green, with the Blue favoured for no other reason than that I quite like the purplish hue it gives.

I’ve enjoyed messing about with the Starnet++ programme lately- so here’s a starless version:

Finally, I think at times I’m guilty of getting too involved with the process of putting these images together and losing track of the incredible size and structure of these objects and the miracle of being able to take pictures of the them from my back garden. So here’s a crop of Melotte 15, the Open Cluster at the “Heart of the Heart”. Our estimate is that this nebula is 7,000 light years distant from Earth and has a diameter of 107 light years across. Using the pixel scale on the original photo (23 pixels=1 light year) I’ve done a (very) rough approximation of our Stellar Neighbourhood around the nebula structure in the middle of the cluster. What would our night sky look like if we had this in the middle of it? Would it have changed our biology, our myths, our history? For sure, it’d make for some pretty cool photos…

(Edit) Quick request from the WhatsApp group – here are the Ha and Oiii that the shot was built from:

 

 

 

 

The Veil

Had a go at the Veil with the 300mm lens on Monday night, using the Quadband filter and Star Adventurer. 2 minute subs was giving me trails so I reduced it to 90 seconds. The forecast said there was only 45 minutes before clouds rolled in, but they held off most of the evening and I ended up with 111 subs and used DSS to stack the best 70%. It’s needed a lot of processing for various reasons (I don’t think the filter and lens get on too well), and certainly doesn’t stand up to any pixel-peeping, but I’m still quite pleased with it.

Using Starnet++

I’d read a few bits and pieces online about Starnet++ – a software module that uses a neural network to identify and remove stars from astronomical images in order to enhance nebulosity and process it separately to stars.
The software is free and you can find it at the link below. It was originally published as a Pixinsight module, but can now be downloaded and run standalone on Windows: https://sourceforge.net/projects/starnet/

I’ve found it’s pretty good- I’ve been playing with it today on an image of the Western Veil I took a few weeks back. This is my original processing of the image:

To use the technique I started again with the stacked file and used Pixinsight to remove the background light pollution gradients, calibrate the colours and do an initial stretch. I then put the image through the Starnet routine and it returned me the image below:

I then used the Clone Stamp tool to clean it all up (possibly more time needed on this!) and tweaked the curves to give it some contrast and got this:

I really like this, but I felt it would be better with some stars blended back in, so I went back to the image I submitted and processed purely to get the brightest stars at a prominence that I liked. I then blended the two images using Pixelmath (in the way I used it here, it’s identical to blending layers in Photoshop or GIMP with lighten):

Keswick Observing Reports: Stargazing, but not as I know it…

Away for half term at the moment and staying in close proximity to some dark skies. Amazingly, for Cumbria, there has also been some lovely clear nights- and best of all, my wife agreed we could bring some astro kit with us. She may not have expected the whole boot to be taken up with it. Good job we have a roof box for the rest of their stuff (don’t ask how many days I’ve been in the same underwear)…

I’ve had two superb evenings, so please bear with me as I’ve got a bit wordy….

27/10/19: Whinlatter Forest Park

The Clear Outside astro weather app was promising a clear night on Sunday so I managed to get out for quick recce during the day. The nearest dark skies looked to be in Whinlatter Forest Park and, whilst the main car park was surrounded by very tall trees I managed to find a side road that had been closed off after 50 yards with pretty good skies and lovely views out across Bassenthwaite Lake and towards Keswick. Arriving around 7:30pm with Sam in tow we were greeted by the view below:

Whilst this was pretty stunning, even better was the view straight up. Our little eyrie was up at 300m, and although Keswick was only 6 miles away the height seemed to take us above the outer reaches of the light dome leaving the Milky Way bright and clear across the sky. The number of stars was breath-taking: much the darkest bit of the sky was the rift running through our galaxy. My friend Ian, who happens to be holidaying nearby at the same time had arranged to join us, and I had the dob set up just in time for his arrival. I’ve bored him in the pub on many occasions with my astro obsession and so it was great that the skies obliged us with such a wonderful display. We started off with a naked eye tour, first of the main constellations and then of the brighter larger objects that we could see- the Pleiades, Andromeda and Auriga cluster all easy to spot with the naked eye (thanks Paul M for the laser pointer suggestion). Then we moved to the dob for some showpieces…

M31 – Was clearly visible with the naked eye so I just pointed the dob at it- no star hopping. Checked in the finder to make sure I had it right and there was the whole thing in the finder! Bright core, elongated shape even M32 visible. Move to the eyepiece (30mm/55x) and it’s like a photo- and clearly bigger than the FOV. M110 was just there- no effort, no AV. Dark lanes prominent. A suitable “Wow!” from Ian. Yeah- it’s always like this, honest…

M27 – Dumbbell – Like M31 I was able to put the scope right onto it, and it could clearly be seen in the finder. In the eyepiece, with no filter, both the applecore and the wider fainter sections were visible. Gorgeous.

M57 – Ring Nebula – Stuck out like neon. A glorious sight with real texture in the outer regions and obvious darkening in the centre, although I couldn’t see the central star.

M45 – Pleiades – very bright and with clear nebulosity visible in patches around the brighter stars.

M81/2 – Bodes and Cigar – Nice rewardingly clear view, although try as I might I couldn’t see spiral arms. Ian very impressed with the idea that

Ian’s kids are younger than mine, so he had to head at this point and with the temperature dropping through zero Sam retreated to the car- I had an hour before forecast cloud to go after some fainter stuff.

M33 – Surprised to see this appearing in the finder as well. In the main eyepiece it was clear as day- and with a spiral structure. I’ve had it before on M51, and flattened in M31- but here it was, laid out in an exquisite swirl across the field of view.

The Veil – I’m quite accustomed to my back garden view of this in O3- sinuous green strands against a pitch background. Here, with no filter, the nebulous regions were brighter and richer, the challenge was only picking them out from the dense star fields that crowded it. East and West were easy to spot but the central sections were harder to pick out. Popping a filter in would have made it easy, but for this night I wanted to see it unmolested, so to speak.

NGC892 – Spiral Galaxy in Andromeda – A nice pleasing streak across the FOV. Tried for some time to see the dust lane, but it was not visible to me. At home this object is not visible at all.

Stephan’s Quintet -YES! I read about this object some time ago: a cluster of five galaxies , four of which are interacting, sat above one of the arms coming off the square of Pegasus. It’s almost a ritual on better, clearer nights at home that I go and have a look and fail to see it. Well here it was. To be fair it was a faint uneven smear: but still- the light of four dancing galaxies 200 million light years away with a fifth nearby at 39 million years photobombing them. Not a bad way to finish the evening.

Oh- and I got a star trail over the Northern end of Bassenthwaite lake:

29/10/19 Castlerigg Stone Circle

Wonderful as Sunday night was, the one downside of the site was that cars coming over Whinlatter pass would sweep their full beam headlights across it. I wanted to do some imaging with my Star Adventurer so tried for somewhere equally nearby that wouldn’t have that problem. Castlerigg is a place I’ve loved for a long time. It was built 3-4000 years ago on a plateau surrounded by mountains. We’ve found no evidence of settlement at the site and it was built pre-Bronze Age- no-one really knows what these early stone circles were for but it was obviously an important and sacred site for the inhabitants of the area at that time. And it’s a heck of a place to sit and look at the stars.

It was clear as soon as I arrived that the conditions were not quite so favourable- the sky wasn’t quite as dark (although the Milky Way was still easily visible), there was broken cloud scudding across it and a pretty stiff breeze across the exposed site. I quickly discovered that the ¼ to 3/8 adaptor had fallen out of my SA as well so that put paid to any serious imaging plans. No worries with the dob in the back of the car ready to go again. From the observing log:

M45 – Pleiades – very twinkly so seeing not great, but nebulosity was clear again. A wonderful sight.

M1 – Crab nebula – quite easy to pick out even with no filter. Whilst I couldn’t see the tendrils that feature in so many images, the uneven shape was nice and clear and there was an obvious fading from the core through to the outer sections, with some uneven mottling within the object.

Double Cluster – I had planned to make the most of the dark skies and focus on fainter objects, but the double is a favourite and was clearly visible naked eye so I pointed the dob at it and was surprised to find that even clusters are enhanced by the dark sky. Just so many stars! So next up…

Melotte 20 – this is barely visible as a cluster naked-eye at home, but here it was almost as prominent as the Pleiades. Pointing the dob at it gave almost bewildering fields of stars- so densely clustered it felt as though they were joined in a net.

NGC7331 & Stephans Quntet- The view was very similar to Sunday night and good to affirm the sighting. I concentrated more on NGC7331- the closer galaxy nearby which was quite prominent and showed a bit of shape. Again- I couldn’t distinguish arms, but it was good to be able to see so much more than from home.

M81- Bodes – Tried again for the spiral arms and spent some time on it. Outer reaches were visible and definitely the shape of the galaxy was not an even circle, but if I’d tried to draw what I could see there would be no arms on it. That’ll have to wait for another dark skies trip.

NGC1499 – California Nebula – This was really tricky to make out. I could detect it more as an interruption to the brightness of the stars in the field than anything else. I tried again with the UHC filter and a sort of fibrous structure was evident, but it took a lot of concentrating and relaxing and averting vision.

IC5070 – Pelican Nebula – As I had the UHC in I popped across to this one, but it was again very tricky to make out. There’s a bright ridge running above the 2 brighter stars and this was clearly visible, but the rest of the object only appeared intermittently in averted vision. Whilst I caught glimpses of it around the field of view I certainly would not have been able to draw the shape of it.

NGC7000 – North America Nebula – It was natural to move onto this after the Pelican. The Eastern seaboard section was similar to the Pelican- hinted at, but not obvious. It started to become more easily visible around Florida and the Gulf Mexico and the Cygnus Wall was quite prominent.

At this point a bobbing white light appeared in my peripheral vision. Someone walking with a torch. I always feel quite exposed when out on my own in places like this and I sat quietly, but with heart pounding, as the light gradually made its way toward me. Then it started sweeping the field, and stopped dead when it found me. Feeling a show of confidence was in order, I waved my hand in the air and shouted out a cheery “Good evening!” as if it’s the most normal thing in the world to be found on your own sitting on an ironing chair in a freezing cold field in the middle of a late October night. The torch again started bobbing towards me and as he came closer I could see he was clutching a tripod and camera bag and was most probably a like minded soul. My visitor turned out to be Javier- a Spanish amateur photographer having a week’s holiday in the lakes.

He was very interested in what I was doing and my equipment, so I whipped out the filter and started showing him some galaxies which he was very taken with. An explanation of what he was looking at, and the distances involved caused some rather pleasing swearing and evolved into a lengthy conversation about the likelihood that the universe is infinite and whether or not the multiverse theory is a pile of nonsense (not the word used).

His mission for the night was to take some nightscapes of the stones with stars beyond, using his torch to paint them in. It’s a fun technique and I was able to join in with my camera , which are the pictures that you can see here (his results were better!).

Whilst he carried on I returned to the eyepiece as Orion was now high above the mountains and above the lighter section of sky.

M42 – Orion Nebula – My first observation this season, at was as always a joy. With the UHC filter in I sent some time just enjoying the bright bow-like “front” of the object and then, with time, the billowing structure of the nebula behind began to emerge. Reflecting on the earlier observations of nebulae that evening, there really are no others that compare to it for me. It’s just an endlessly rich and fascinating object.
NGC 2024 – Flame Nebula – feeling encouraged by the fabulous views of M42 I slid the scope up to Alnitak for a gander at the Flame nebula. I found that the UHC filter didn’t really add anything (especially as the blue/red separation it puts onto Alnitak is a bit distracting) so I took it out and found that I could still see it. Far more obvious than at home it appeared as two prominent patches separated by a dark lane. The branches that you see in images couldn’t be seen at all, but the shape was very clear as was the central dark lane.
IC434 – Horsehead Nebula- finally! This was not easy at all. Following guidance I’ve read here and elsewhere I tried with a H-Beta filter in my Baader zoom but this wasn’t showing it at all. Switching back to the 30 mm with no filter I went through the ritual of just circling the area with the positions of the local prominent stars in my mind. The nebulous bank in which it sits was quite straightforward and with time the Horsehead appeared as a notch in it, a clear area of darker sky through the brighter part of the nebula, but not cutting all the way through. I couldn’t see the famous charismatic shape but the dark cut into the nebulous bank was there, as well as some hints of the shape in the clouds beneath it (I probably wouldn’t have been able to discern those clouds but for the darkness of the HH bit).
I called Javier over, but the stiffening breeze was making it very hard to keep the scope in place and I was unable to show him. As it as 2am and he wanted to be up to photograph the dawn at 6 he announced that it was time for him to turn in. Reluctantly I also started to pack up.

Reflecting back- what a couple of nights! My first time with a large-ish dob under pretty dark skies: it will not be the last. If you’ve read this far then- thank you – I’ve had fun re-living the experience and I would finish by repeating that the old cliché about the best upgrade to your telescope being petrol is one that I now firmly agree with.

Filtering the Crescent

Over the last couple of weeks I’ve been imaging the Crescent using different focal lengths and filters

Widefield 135mm

I was working out that this is the fourth time I’ve been imaging in or around the Sadr nebula. On this occasion it was because I’d already started on the data for 900mm shots of the Crescent and I thought it’d be nice to have a wider shot of the general area, putting it into context. I was inspired by Neil’s recent results with his Triband filter to see if the same (or similar) technology in a clip filter would help with wide frame nebula images and acquired a Skytech Quadband (that transmits 2 35nm bands around Ha, Hb, Oiii and Sii – hence the name) . I must say I’m quite impressed- I got this from a sequence of 20x 150 second captures on Sunday night under a 99% moon using the Russian made 135mm vintage lens I’ve posted about previously. Normally I’d only attempt proper Narrowband under these sorts of conditions, but I thought it coped pretty well under the strong moonlight. The only slight concern is the halo around Sadr itself.

The photo picks out how prominent the Crescent is (below and to the right in this picture), but also shows how “busy” this bit of sky is- the Butterfly nebula pops out, with its prominent dark lane, but the fainter cloud that it’s a part of extends beyond the frame. There are also clusters aplenty- my favourite is M29 – the Space Invader cluster just below and to the left of the centre. Probably my eighties upbringing…

Hydrogen Alpha

These are taken using a Baader 7nm Ha Filter on a modded Canon 550d in a Skywatcher 200p- altogether I got 12 10 minute subs before clouds stopped me. I think this is the best of the shots for showing the structure of the object and the shockwaves that form its shape; the monochrome also highlights the cloud of the larger surrounding nebula.

Oiii

This came from the same setup and 10 more subs, this time with an 8.5nm Oiii filter, and a 99% moon on 13th October. The only Oiii visible in this shot is around the nebula itself. The signal was quite a bit weaker than the Ha; this picture was created by discarding the Red Channel and then combining equally the Blue and Green using Pixelmath in Pixinsight.

Bi-Colour

Finally, it’s all brought together using the same process- this time feeding the Hydrogen into the Red channel and the Oxygen into the Blue and Green. I spent quite a bit of time playing with this one. Just feeding the data in, the red was total dominant and I progressively multiplied the Blue and Green until it was more prominent (the eventual multiplier used was 2). I also experimented with trying to change the balance to bring a little more colour into it, but that also artificially unbalanced the star colour so I decided to leave it even, which makes the Oxygen mostly white when combining with the Hydrogen.

I’ve really enjoyed taking these different views of the same object and learning about it. The nebula itself, 5,000 light years away, is 25 light years across and is caused by fast stellar winds erupting from the Wolf-Rayet star visible at the centre of the nebula. It’s thought the star will imminently (in astronomical terms) become a supernova.