Rob Leonard

Aperture Mask: Yes. Pluto: Not so much.

Got home from the trustees meeting last night to a glorious clear sky. On a Monday? Really?

I made an aperture mask for my dob over the weekend and was itching to try it out. The idea behind the mask is that on bright targets cutting out a bit of light and diffraction from the secondary struts should improve clarity, even though the aperture is reduced (350 to 160 in this instance).

And so after failing to resist temptation I was setup by 11:20:

Jupiter: Disappeared behind neighbors house. Need to catch it in the gap between house and apple tree 1.

Saturn: Seeing dreadful without mask: boiling away with no clarity at all. With the mask: same but dimmer. Hmmm.

Pluto: Spent ages looking for this. Definitely in the right place. Pluto formed a triangle asterism with two other faint stars. I upped the magnification to dim the sky glow and there was definitely something there. Wobbled the scope – that helped. Averted vision- didn’t make much difference. So- I’ve looked at Pluto but not seen it! Beginning to regret doing this on a work night…

Jupiter again. Behind apple tree 1. That moved quick! Damn!

Izar: At last- some success. Successively improved views moving from Baader zoom to binoviewers to adding aperture mask. In the final view the stars were pinpoint sharp and well separated with the companion showing a lovely blue.

Double double: the same experience. The 2 pairs were easily separated in all 3 configurations, but the binoviewers plus aperture mask gave the best view.

M13: Too dim for the mask, the best view was in the binoviewers- resolving all the way to the core and seemingly spherical, even though at that distance you don’t really have depth perception!

Jupiter again: Gotcha! Just before it snuck behind apple tree 2… Definitely a better view with the aperture mask- slightly dimmer but with much more clarity. 6 bands plus the GRS were clearly visible, with some detailing on the bands, plus the moons spread out as clear disks 3 to one side and one on the other.

Well worth the fatigue today!

Very pleased with the aperture mask- it’s not often an astro upgrade is almost free. It’s only really good for bright objects and with the binoviewers I had to velcro 4kgs onto the bottom of the tube to balance it- bit well worth the hassle!

Fading Noctilucent Clouds

Popped out for a quick session on Friday night and there was a lovely Noctilucent Cloud formation to the North, so I popped my camera on a tripod and recorded it.

The video above was using a Canon SL1 at 22mm f4 taking 265 shots between 23:49 and 00:30. I used Pixinsight for a curves tweak and some unsharp masking and then Videopad to string it all together and add a bit of music.

The red light in the foreground for part of it is me setting up the dob. It doesn’t really add to the ambience- but it led a pretty good session despite needing to do a bit of cloud dodging. Finally got the Binoviewers dialled in for some good views of the Double Double, Izar, Albireo, M29 and M57. Really surprised that at similar magnification they outperformed my 7mm Celestorn X-Cel Eyepiece- the split on Izar was really clear, and the companion was a vivid blue, wheras the Celestron had them fuzzier and less colourful. Even Saturn came out to play- and despite hugging the horizon, the seeing gave me glimpses of the Cassini division plus Titan, Rhea, Dione and Enceladus. Best of all was M13- it resolved close to the core, but with tails everywhere- it looked like a ball of wool after a kitten’s been at it!

Eta Carinae: Mucking about with someone else’s data

With the long evenings precluding any weekday astro activity at the moment I decided to get a fix from Pete Williamson’s data that Andy provided for RAG members on this blog.

I didn’t want to get data for something that I could image myself so I went for Eta Carinae Nebula, which is a Southern Hemisphere object. You can read more about it here, but in summary it’s a very large and bright nebula (4 times the size of Orion, although further away) and after spending a bit of time playing with it on a computer I’d love to point a telescope at it.

The data is, as you would expect from top end gear working in a complete absence of light pollution, terrific. It comes pre-calibrated (although the SHO image below had a few hot pixels appearing in it), and both the images below had 3x 5 minute subs for each channel (so the HaRGB is an hours data, whilst the SHO is 45 minutes). I’ve never managed to get my head around pre-processing on Pixinsight so I used DSS to stack each channel then registered and merged them in Pixinsight using Pixelmath. I was able to drop background extraction (which tackles light pollution and other issues) and noise reduction from my usual workflow, and used only a tiny bit of sharpening.

I’m more taken with this approach than I expected: it doesn’t bring the same feeling of achievement that creating your own image does, but it was great to be able to explore such a large and beautiful object that you can’t see from this side of the planet and I love the finished product. It also gave me a chance to work with mono data for the first time and learn how to create an image in the SHO palette as per Hubble. In summary, I’d rather work with my own data, but this was a fun thing to do and I’ll certainly look forward to finding another Southern Skies object to explore in this way.

A Year of Observing

“You’re writing a blog about a spreadsheet???” My wife has just discovered that not only have I adopted the habit over the last couple of years of sitting in the garden on clear dark nights and then making notes about it, but I’ve then been putting it into a spreadsheet and getting statistics about it. And now I’m sharing it in public. She’s giggling at me with what I hope is affection…

Last year I bought a 14 inch dob and after a few months enjoying the views and wandering through the skies I decided I wanted to be a bit more rigorous and start planning my sessions, so I started making notes on my phone of what I wanted to look at after reading observing reports on the web. I quickly moved onto recording the success or otherwise of these observations on a black notepad on my phone (to minimise disruption to my dark adjustment, although to be honest, in Bortle 5 skies it doesn’t make a huge difference), and it was a short step from there to Excel. I just spotted I’ve been doing this for around a year so I thought I’d share it, partly out of curiosity to see how it compares with others experiences…

Stating the obvious: we get quite a lot of cloud.

If it’s clear, I’m not doing family stuff and work’s not in the way then I’ll go out and observe. Altogether I’ve recorded 26 sessions. I’m pretty sure there have been more than that- if I’m observing in company I’m much less diligent about recording it. I also sometimes have quick sessions with my 8 inch for half an hour and I’m a bit rubbish about recording those too. So: 26 is roughly the number of ‘proper’ sessions where I’ve sat outside with a target list and written it down. From this I reckon twice a month is a good working average for how often I can do a ‘good’ session.


No of Objects 149
Messiers 65
No of Observations 280

If I was a bit disappointed to realise how infrequent observing sessions are, I was quite surprised by how many objects I’ve managed to record during that period- including quite a good chunk of the Messier catalogue. I suspect I’ve managed to get through most of the easier ones. From my location, although my southern horizon goes down to a few degrees in places, I’m looking directly over rooftops and at the dome of light pollution of Burton on Trent and often the orange haze makes finding reference stars to hop from very difficult, so I’ll probably need to make more effort to get to dark sites to grow this list a bit.


I wasn’t surprised to find that there are some objects I come back to again and again, but I was quite surprised to find the Leo triplet at the top of the list, although on 3 of those occasions I couldn’t find NGC3628. M13 is less of a surprise, I never get tired of looking at it and trying to resolve as far as possible into the core. I notice that over time I’ve been less inclined towards the higher magnifications. The Double Double is a favourite first port of call, both because it tells me how good the seeing is, and also whether my mirror has cooled. Plus, I love the idea of it as a vast interstellar executive toy- with six components that we can’t see. I’m sure M42 would have overtaken all of these if it were visible for more of the year and not so subject to winter weather.


Something I’ve not done much of is logging how often I can’t find or see things. The Horsehead is conspicuous by its absence (I picked up an H-Beta filter in March, but just missed out on the HH) and I really want to see Stephan’s Quintet visually- this will need darker skies! I suspect that if I was logging more diligently the times I’ve failed to find either of those targets they’d be quite high up on the list and I’m going to start doing that. I’m also going to record a bit more about where I observe (usually my back garden) and what equipment used.

I’ve attached the spreadsheet I’ve used in case anyone wants to re-use the format- it’s pretty basic and has just sort of grown organically as I’ve added bits and pieces to it. It’s a bit of effort to keep it up to date, but I’m glad I did it as it’s been interesting to look back over it and remind myself of what I’ve seen- It’s also a reminder of how great visual astronomy can be when you’re suffering the frustration of several weeks of cloud cover.

I’m going to brush over the slightly worrying and repeated experience, of reading about targets, thinking they sound great, then finding I’ve already seen them…

Log 18-19


Catching up on Images

It’s been something of a hectic week, so it was nice to have a chance this weekend to download some pictures from last week, when Andy and James were round, and do a bit of processing.

Firstly- the best of the moon photos. These were mostly captured with my Meade ETX105 Mak, which I’ve mounted on my HEQ5 mount, because the original mount is not reliable. The pictures were taken with an ASI224 camera through a 2x Barlow- which gives a focal length of 2.8m and a hard time focusing! Each image is a 30second avi that I  stacked using Autostakkert, and then the multiscale process in Pixinsight for the sharpening. This seems to work in the same way as wavelets in Registax.

This is one of Sam’s of the Mare on the Eastern Side:

This is one that James took centred on the Cuvier crater:

This is one of mine – I loved this view, because you can just see the summit of the central mountain in what I think is the Walther Crater, upper left. This view was stunning in the eyepiece. If I’ve identified it correctly then this little spec is 4.1k high- i.e. it’s a similar size to Mont Blanc sat on a crater floor that’s about the same size as the entire English Midlands.

Finally, on the moon, from a bit later in the week is Montes Jura, which is the prominent range towards the top of the picture. This feature is 3800m high and 422km long- it’d be a pretty substantial mountain range here on earth.

Next up were some globs, which are a great target when the sky’s not properly dark. I took these with the 130pd-s, and again used the ASI224, but taking 20 second .pngs rather than .avi’s. The mount was unguided (the ASI224 is usually my guide camera) and even over 20 seconds there were some wobbles so when I stacked it I set DSS to only take the best 50%. Each imaging run was 30 minutes, so these are effectively a 15 minute exposure and all use darks and bias frames. I took flats as well, but between M92 and M3 a big lump of something landed somewhere on the image train which meant they could only be used on the last 2 images.

First up was M13:

Next was M92. I’d normally crop and re-size this to present it better, but I wanted to make it comparable to the M13 pic above, so all the settings are exactly the same, although my processing has yielded a slightly different background colour. You can clearly see M92 is a bit smaller, but I think it’s also neater and more compact.

Next up was M3- again with the same parameters:

Finally, I had meant to go over to M5 and get another glob, but went for M64, the Black Eye galaxy. I took this with exactly the same parameters as the globs above (mainly because I was having fun doing visual and didn’t want to faf around with settings). I’m quite pleased with this; at the Practical Astronomy Show earlier in the year Dr Robin Glover (author of Sharpcap) gave a talk about how, for CMOS cameras, long exposures are not necessarily needed, or, indeed, optimal. This has enormous potential, because, by stacking loads of shorter sub exposures instead of a small number of long ones, it greatly reduces the precision (and therefore cost) needed for an AP setup. Well, that’s all well in theory, but I’ve had a go at M81 and NGC2903 using this method and the results were pretty pants! In this case, the exposures, at 20s were a bit longer, and the gain a bit lower and I’m really pleased with the outcome. I mean you can see what it is, which is more than can be said for the other 2 I’ve had a go with.


Moon, Methane and Messiers

Splendid night of observing and (hopefully) imaging last night.

Sam had his mate James round, and then Andy T came over to join us as well. Due to the long evening twilight and the terminator being in a prime position on the moon, we started there. Once they’d got the hang of it the 2 lads were thoroughly enjoying scanning up and down the terminator taking videos of moonscapes, which when I get some time will hopefully become some nice images.

The areas we looked at were the craters around the South Pole (Scott and Amundsen!) then worked our way down (the image appeared upside down in the mark/planetary camera) past Cuvier, Stofler, Albertegnius and Hipparchus toward the smoother area that’s more dominated by mare. The highlight for me was Albertegnius which was just in the perfect position to be in complete darkness, but with the sun illuminating just the summit of the central peak.

By this time Andy had set up his spectroscopy rig and took a reading from the moon- and matched in to an internet reading of the sun- explaining to the lads that this was because all the light coming from the moon was reflected from the sun, and how the technique enables us to derive what the elements are in the star.

We also did some visual exploration of the terminator- and no matter how amazing the views of the moon through the planetary camera, there is nothing for comes close to the stunning HD quality through the eyepiece. Even at 465x through the zoom the view was sharp and full of contrast; a really stunning view.

It was, by this time, bed o’clock for the boys, but Andy and I carried on. First step was swapping the mak for the 130pd-s and setting some imaging runs going on globular clusters with the planetary camera as I felt that the glare from the moon made any other targets a bit unrealistic. I’ll post these when I get the chance to do some processing!

For the same reasons I decided to go for similar targets visually whilst Andy did his spectroscopy and we shared the results with each other. First up, though, was the double-double- it didn’t split as easily as normal which suggested the seeing wasn’t great (I already knew my scope was both cooled and collimated). Nonetheless I pressed onto some globs:

– M13 Obvs! Always a lovely sight. Whilst there Andy moved the scope onto NGC 6207- a new one on me, and just next to M13. It was a struggle to see and needed averted vision to spot, but at Mag 11 the skies cannot have been too bad to pick this up.
– M92 It’s a bit smaller, but somehow feels more compact and symmetrical than its big brother.
– M3 Again- like M92, more compact and symmetrical. It was nice going through these one after the other- on their own globs are all similar, but when looking at them one after the other you really start to see the differences.
– As we were in the neighbourhood popped over to see the Whale galaxy- several club members have been imaging this lately so it was good to have a proper look. With proximity to the moon it was quite an effort to find this and I had it in the eyepiece for quite a while before I was sure I had it. By relaxing and just looking around the target it became obvious how huge it was- nearly filling the ep at 210x. I couldn’t make out the distinctive shape, however, and neither could we spot NGC4656
– Next stop as M5, which was visibly smaller, but with a dense bright core and was pleasingly circular.
– The next Messier glob easily visible looked to be M9. Whilst aiming the scope Andy asked about the bright light in the same direction- which is over towards East Mids airport- and we both agreed was clearly a plane- although not moving too much. Realising that this meant it was heading towards away from us I tried to aim the scope at it, because sometimes it’s a great view in the eyepiece. This plane turned out to have horizontal banding and 4 moons. JUPITER IS BACK!! Albeit hugging the horizon in a boiling atmosphere. Because of this the views were not brilliant, but it was great to see after a long break. Andy quickly headed back to his spectroscopy gear and lined it up- the result was a mixture of the same elements we’d found from the moon, plus a couple of lines for methane. Very pleasing! I then moved onto M9 and caught a quick glimpse, but was kneeling uncomfortably over the telescope by this stage and was getting decidedly cold so we decided to head in for a cup of tea in the warm and to look at Andy’s spectroscopy results.

Suitably refreshed, and with the moon down near the horizon the sky was darker, but also more hazy. We decided to look at some summer targets and started off with the Ring nebula. I think the effects of time and cold were beginning to set in by this stage as I struggled to get it in the eyepiece- not helped by the fact that everything was dewing over. Andy quickly rectified this and we were rewarded with some lovely rich views and spent some time comparing the views in the Baader zoom with Andy’s Binoviewers. The conclusion was that the binoviewers offered a different experience- more natural and pleasing to look at, but also there was some loss of detail. Partly this is caused by the higher magnification available to the Baader, but we also thought it may be down to the greater number of optical surfaces involved on the binoviewers. We returned to M13 to see if we’d find the same outcome- and it was pretty much the same; although the binoviewers rendered the glob as a sphere- a wonderful view.

I’d have liked to try them out on Jupiter, but by this point it was behind the neighbours house, so we returned to deep sky targets instead- trying for M51. Unfortunately, by this point, the sky was pretty hazy and despite being certain I had the dob in the right place, I could not see the galaxies. Spent a while trying to remove dew from EPs, finders etc, but it was pretty clear that the sky was lightening and it was time to pack up. Big thanks to Andy for coming over- observing in company and sharing ideas adds so much to an evening and the output from the spectroscopy was really interesting!

Spectra of Moon, Vega and Jupiter taken with CCDSPEC on Sky Watcher Equinox Pro 80mm scope with Rob Leonard 11-12/5/2019

Rob kindly invited me around for an evening of observing. The Moon was half full and high and the humidity level high with mosture all over our telescopes but we still had a whale of a time – quite apt description as Rob found the Whale Galaxy for an amaxing view in his 14 inch Orion US scope – all star hopping – well done to him!!

I took some spectra of the Moon, Vega and Jupiter, using my CCDSPEC spectroscope on my Equinox – I know manual alt-az mount is not ideal but it is transportable so I used my Manfrotto mount tonight manually guided and star-hopping to targets – limiting me to bright targets. I would still like to take spectra of the Ring Nebula but I can’t see it in the CCDSPEC so I do need my EQ6 or HEQ5 mounts up and running to have a chance with that….

Particularly exciting tonight was our spectra of Jupiter, showing methane absorption lines – Jupiter’s spectrum is essentially that of reflected sunlight but its atmosphere does absorb light in the methane bands.

Rob and I were able to identify two of these bands in our spectrum this evening of the planet.


In spectra below my spectrum from tonight is in red and reference spectrum is in blue.

Moon – essentially this is a solar spectrum from reflected light:

Vega – Balmer series lines very obvious:

Jupiter – showing two methane absorption lines – one of main features that are different between Jupiter’s spectrum and the solar spectrum (In spectra below my spectrum from tonight is in red and reference spectrum is in blue).

Bodes & Cigar

From Sunday Night- there was little bit of darkness before the moon rose and I had a go at the M81/82 pair. This has long been a favourite target visually, and so I decided to have another go at imaging it- this time with my 8 inch scope and with another 15 months imaging experience under my belt.

Capture details: 24x 4mins with IDAS D2 + Darks, Flats & Bias.


This is my go at Messier 51 from Thursday night, using the 200p f5 Newtonian that I picked up earlier this month. My first effort at deep sky with the scope had a few issues with collimation and focus, but a bit of time spent tuning it up seems to have yielded a much better result. This is one of my favourite targets, both for observing and images. To get a grandstand view of a galactic collision with an 8 inch dob in my suburban garden is one of those special moments that makes me love this hobby. In images, I love the stream of stars flung out into space from the encounter- this is the first time, after 3 attempts, that I’ve caught a bit of it.

This image is 35x 4 minute subs with 20 each of flats, darks and bias. Camera is a modded Canon 600d, stacking is in DSS and processing is in Pixinsight.