Moon

Moon

Friday, 25 November 2016

Preparing for very large sketch works

I have recently been commissioned to do a sketch of a very particular object, the Large Magellanic Cloud.  Both an honour to be commissioned by a professional astronomer for this piece, and also terrifying by the very nature of the beast I’ve been asked to chase down.

Every now and then, I find that a particular object I am considering to sketch, some preparation needs to be made.  Some of these preparations come from previous experiences and how they relate to my style of sketching.  As an example of one aspect of my sketching style is how I don’t use a “field of view circle”, or as I affectionately call it “The circle of Death”.  I tend to develop the scale of an object pretty much on the fly, letting the natural action of my wrist and fingers begin the scaling process and the rest takes care of itself.  And to this, an A4 sheet of paper is usually plenty big enough.

There are a few objects however that I recognise as being so large that an A4 sheet wouldn’t be sufficient to accommodate them.  For these I sought out an A3 pad of black paper in order to sketch them.  The Orion Nebula is one example where I deliberately used this larger sheet size.  As too the sketch of the Andromeda Galaxy.

This last one however brought to my mind that there are even some objects that even A3 is not big enough.  For me, the finished sketch of M31 is a little more “constricted” than I would have preferred.  If I had started the sketch with a slightly tighter wrist, and made the initial brush strokes tighter, then the final sketch would have been less constricted.  But the difficulty is anticipating the ultimate amount of expansiveness that M31 is to reveal.  So for the Andromeda Galaxy, I feel I still did pretty good, despite my own critique.

Now, the LMC is a different beast altogether.

While M31 has a maximum angular dimension of some 3°, the largest dimension angular dimension of the LMC is some 10.5°!  Flaming enormous!  Knowing my own style of sketching, I can see that even with an A3 sheet I would struggle to fit the LMC.

So, I need to build a larger easel to accommodate a larger sheet as the one I currently have can take an A3 sheet and no larger.

It is also not just a simple matter of scaling up what I currently have.  I also need to consider the experiences that I’ve had with sketching in the night air, and work out some ways in which to counter some of the problems that can be encountered.

One thing that is seen through the eyepiece during an extended examination of an object is the apparent rotation of the object in the field of view as the objects transits through the sky.  So to work with this is to rotate the sheet.

Another difficulty that can arise comes from dew.  While the shielding that the Coreflute wrap that I have over my current easel works very well most nights, it is those occasional nights of excessive humidity that overwhelms the shielding and the paper warps as it absorbs excessive moisture, and the texture of the paper is also altered to the point that it becomes soggy and impossible to continue working on without causing damage to sketch that’s been laid down.

Even how to illuminate the large sheet needs consideration.

So, time to work on Sketch Easel Mk II





I decided to utilize the same clamp mechanism to hold on to the sheet.  It is simple and effective, and with a little thought it can be made to allow for a broad rotation range of the sheet.  To help control any possible flapping from gusts of wind, I devised a few clips made from wire that I bent into shape.  These clips gently hold the paper down and their long reach allows them easily reach the paper even when it is tilted for rotation purposes.





While the shielding I’ve made has more overhang than the first Easel, if the night happens to be a humid one, particularly with the longer amount of time that this piece will take me, I’ve had to come up with some system by which to help control dew soaking into the paper.

I’ve long thought of different way that this could be achieved.  Heating the paper is one way, but the power requirements of such a heater is large and complex to design and fabricate.

I then thought about the way we control dew with our scopes – with the movement of air.  Dew does not form on a surface that has a constant stream of air flowing over it.  So I came up with a battery of fans to blow gently down the face of the page.  I’ve used two fans rated at 12V, installed in series so to reduce the airflow to a gentle blow, and not have the easel become airbourne.



Of course, this dew mitigation method for paper is purely experimental, though not without pedigree.   Time will tell how effective it is.

The lighting aspect I’ve addressed by having additional anchor points for the dual lamp that currently use.  I’ll also have some extra little reds lights in my pocket and tape in case I find I need some addition illumination.

Now that the Easel is done, I just need some eyepiece time with the Large Magellanic Cloud…


Alex.

Friday, 19 August 2016

Selecting a site for Astronomy Purposes

Hi everyone,

No matter your niche within astronomy, we all want to find the best location that is most favourable for our pursuit.

While we take it as a given that we want a dark sky, just a clear open paddock is not necessarily the best location.  In many instances, that clear paddock is actually the worst location we could use when a significantly better site could be just a little further along.  All that may be missing is just knowing what the optimal site conditions are in order to identify the better locations.

Selecting the best location can also have a major impact on the bane of all astronomers - dew.  A good location can just about see dew eliminated as an issue instead of being unavoidable.  And of course the elimination of dew as a problem significantly reduces the complications associated with needing to deal with it.

But site selection is also a case of compromise.  And the optimal site location may not be attainable.  Yet by being aware of what the optimal is, then the best possible compromise location can be found.

And above everything else, the site needs to be safe.

You will find my article on site selection in the new page titled "Selecting a site for Astronomy Purposes".

Clear skies,

Alex.


Even the ants on the Sun are BIG!

Hi everyone,

I love apophenia, or patternicity, and how it plays on our minds.

Apophenia, or patternicity, is the way that we see patterns in otherwise chaotic noise.

With my love for the astronomy, I am open not just to the beautiful, but also the quirky side of things that are totally the realm of our imagination - seeing things that are not really there.

A little earlier in June I found a "Tethered Dragon" within the shape of solar prominences.

This time, I found a giant ant crawling over the limb of the Sun!

Now, we have some pretty big and nasty ants here in Australia.  And some have an attitude to match!  But this formicidae is just something else!!!

Complete with its antennae, a set of wings, and mandibles, this wee ant seems to be munching away on some poor unsuspecting prominence, building itself for its eventual flight into the great abyss of space.  Kinda creepy and cool at the same time, eh.

A sensational hedgerow prominence.

Object:  Solar Ant
Scope & Gear:  ED 80, Daystar Quark, approx. 110X
Date:  17th August, 2016
Location:  Sydney, Australia




It's wonderful being human!

Alex.

Tuesday, 16 August 2016

Video of me sketching the Lagoon Nebula

Hi all,

My friend Ed Malones filmed me sketching the Lagoon Nebula during our time at the 2016 Queensland Astrofest.

The video is a time lapse of some of the three hours the sketch took.  I asked Ed if he could film me while sketching.  I didn't want the sketch process filmed as it would have been a very difficult process as the dim red lighting would not have made the filming process easy - close to impossible.  Instead I asked for him to film me at the scope while I sketched, with the Milky Way slowly moving and any activity happening around me.

In the video you will see the hub of the Milky Way around Scorpio and Sagittarius slowly 'fall', and my telescope slowly follow it.  You'll see red lights come and go as people moveabout the place.  You'll see my Gondwana Telescopes banner move around in the breeze, and my friend Oleg using my 8" dobbie behind the banner.  And you'll see people stop by me to have a look and a chat.

You'll also see at the 21 second mark an exploding meteor between the tree and my banner!!!  What a lucky score!

The Lagoon Nebula is a tiny bright dot above the dark nebulosity that forms The Horse Of Sagittarius, and just below and to the right of the bright Cloud of Sagittarius.

Thank you Ed for making such a lovely video.

Alex.



Friday, 12 August 2016

Queensland Astrofest, 2016

I had the opportunity to visit the great star party that is the Queensland Astrofest for the first weekend in August.  I had a great time up there, meeting fantastic folks, and sponsored the event through Gondwana Telescopes, an enterprise of mine.

The trip up started not so well.  My family had all been sick with nasty colds the week before, and I was trying just about everything possible to avoid also coming down with a cold – I’m crook for a fortnight if I get sick.  Everything was going well until the morning of leaving home when I woke up with a sore throat, stuffy nose, and feeling rather miserable instead of excited.  Oh, well…  Do what we can, eh.

I managed to get two gorgeous clear nights.  The second night I hosted a Sky Tour for those folks who were new to astronomy.  I love doing these outreach events, sharing my passion for the night sky, and show to people that astronomy is not all about high level science, but allows people to take their involvement in things astro to as far or complex as they want.

A good friend, Ken Wishaw, also took a photo of me one night while I sketched.  Below is the lovely picture he took.  Immediately above my sketch pad you can see Antares and Saturn, and the body of Scorpio twisting up towards the upper left.  And just above Saturn you can see the Horse of Sagittarius dark nebulosity.  I can count at least half a dozen deep sky objects that this photo of around 30 second exposure picked up.  Thanks for the photo Ken – I now have it as the background image on my computer! J




Ken’s pic was taken while I was doing the third sketch at Astrofest, that of the Lagoon Nebula, so I’ll expand upon that sketch later on.

Normally I don’t make plans for a sketching program for an evening.  Usually I’ll have some idea in my head about what’s up for a given night, and sketch following how the night pans out.  However for Astrofest I went with a program of objects that I really wanted to sketch.  I went as far as noting in which order to visit them depending on the timing of the evening.  Given that the first night started overcast with the sky clearing around 9pm, and the second night I conducted the sky tour, the first part of my program wasn’t able to be fulfilled.  And then with the miserable cold I was now also sporting, completing three of the remaining six programed targets, I was pleased with the outcome.  Particularly considering the time a couple of these pieces took.

The first night I managed two sketches.  The first of these was the Helix nebula.  In my 17.5” scope, it is a surprisingly large and bright planetary nebula.  At first is looks a bit like a ring with a hollow that is a little less brilliant than its circumference.  But as time goes on with examining the Helix, subtle details begin to emerge, such as the almost rhomboid overall shape it has, the textured ring with its jagged spiral ends, some of its soft extensions, and its little central star.  It is almost bizarre to think that it is no longer a star at the core of this nebulosity, but the core of a one-time star, with the bulk of its material having been blow out into outer space like a giant smoky balloon.  What once lay hidden from view for billions of years, is now exposed and due to slowly fade away, and set to exist for all eternity eventually as black, cold and super-dense lump of a dead star’s heart.

Object:  Helix nebula, NGC 7293
Scope:  17.5” f/4.5 Karee dob
Gear:  24mm 82° eyepiece, 83X, OIII filter
Date:  5th August, 2016
Location:  Camp Duckadang, Linville, Queensland, Australia




The second sketch for the night was the mighty Andromeda Galaxy.  Alas for us here in Australia, Andromeda is never very high in the sky for us.  And a good view of it really demands good transparency to have any chance of pulling out details.  Fortunately, this evening provided really good transparency, and an amazing amount of detail was possible to observe, and the longer my sketch went on, the more detail and the further and further out the monster extended beyond its core.

I recently asked on an astronomy forum about the HII regions within Andromeda, and how come they were not anywhere as easy to view as those within M33 & M83.  The reply I got from (JT) was not what I expected, and astonishing.  Despite the significant tidal influence exhorted on M31 by its two companion galaxies, M31 is relatively poor in star forming regions.  Much of the free gas and dust capable of star formation is close to exhausted, so it is not as rich with massive HII regions.  And those HII regions that do exist are small in size, and greatly obscured by the dust within the spiral arms.

Also mentioned was the single largest and brightest star cloud within Andromeda, NGC 206.  Often wrongly labelled as an HII region, it is essentially just a massive star cloud now, with no HII areas visible to visual examination of the cloud.  Attempt to spot NGC 206, and using a blinking paddle to try to spot HII regions within it and the rest of M31 would be on the cards.

The image of M31 was just staggering.  Just about as good as it gets for us here in Oz.  It is curious how Andromeda slowly reveals here treasures, demanding your time and attention in order to be given the honour to view them.  Be brief with her, and she is fickle.  Take your time, caress her and pay her the attention that she deserves, and she richly rewards you.  This way she shows first her mottled centre, with her large, almost stellar core.  Then comes the first layer of extensions past her centre, with good transparency revealing the dusty lanes in the foreground.  She then begins to show the two outer lobes, which are uneven in brilliance, one being more diffuse than the other.  Next comes a glimpse of NGC 206 if you are really paying attention.  And finally, when she is convinced of your sincerity, she shows off her faintest extensions, soft like the breath of an angle, and stunningly long – Andromeda is one very big spectacle.

NGC 206 appears in the sketch as a brighter patch in the left lobe.  I was absolutely thrilled to be able to spot this feature.  I felt like I was at a Burlesque show, catching fleeting glimpses of seductive details.  I used both OIII and UHC type filters to try to tease out any HII details, but none stood out, as was mentioned to me.

This sketch shows approximately a 3° true field of view, which is more than twice the field visible in the eyepiece I used, 30mm 82° Explore Scientific. 

Object:  Andromeda Galaxy, M31
Scope:  17.5” f4.5 Karee dob
Gear:  30mm 82° eyepiece, 1.23° TFOV, 66.7X
Date:  5th August, 2016
Location:  Camp Duckadang, Linville, Queensland, Australia
Duration:  approx. 2.5hrs




The final sketch was done the following night.  Here I revisited the Lagoon Nebula that I sketched last month.  There were some elements with which I was not too happy about last month, and following the introduction to titanium dioxide pigment powder, I was most keen to revisit The Lagoon.

Transparency was very good this night too.  One major difference between this visit to the Lagoon to the last was I was not as fatigued as the last time.  This had a major effect on the detail I was able to see and lay down reliably. 

As the sketch progressed, I became aware of how long it was taking to lay down the nebulosity.  The difficulty was not the brighter areas, but the soft outer extensions that kept on extending further and further out the longer I examined the Lagoon.  At one point I caught myself exclaiming “Oh, when the blazes are you going to stop!”

But I was in for a surprise that made the three hours spent with the Lagoon very much worthwhile.  While working on the details of the dark lane, I started to pick up hints of another dark feature.  When I looked a little closer, lo and behold, it was a Bok globule!  Sensational!

By the time I finished, I was well and truly spent.  All that was left to do was to put the big scope to bed for the night and turn in myself.  A long and satisfying second night.  And room for improvement.

Object:  The Lagoon Nebula, M8
Scope:  17.5” f/4.5 Karee dob
Gear:  24mm 82° Explore Scientific eyepiece, UHC type filter
Date:  6th August, 2016
Location:  Camp Duckadang, Linville, Queensland, Australia
Duration:  approx. 3hrs




Friday, 29 July 2016

My Sketch Pad Rig

Hi all,

Thought I'd share the sketch pad rig that I use, and how I came about to creating it.  Pretty much a case of necessity being the mother of invention, but into the mix was some good fortune and the local council elections!

You will find the article in the "Telescope Bits and Bods" page of my blog.  There you will find other bits and pieces that I've come up with too.

Alex.



Tuesday, 26 July 2016

Back to School - a lesson from new friends.

Hi all,

The last DSO sketch I did, that of the Lagoon Nebula, you may recall I was not totally happy with.  Thing is, I encountered a limitation of the soft pastel dust I use with the Mellish Technique.  The limitation is not being able to lay down a sufficiently dense/brilliant amount of the soft pastel dust.  This is not normally a problem.  However, occasionally there is an object that has a particularly brilliant glow, such as the central hub of the Lagoon Nebula, and also the glowing nebulosity immediately around the Trapezium in the Orion Nebula.  Come to think of it, my last sketch of M42 planted the seed of dissatisfaction as I really was not too happy with the shading density/opacity of the area around the Trapezium.  And this Lagoon Nebula sketch brought it to a head.

A friend of mine, astronomer Dr Renee James, introduced me to a close friend of her's, artist Lee Jamieson.  The correspondence we've shared regarding my work led to Lee suggesting I try powder pigment colours, such as powdered titanium dioxide or zinc oxide.  These pure pigment colours are essentially pure titanium and zinc compounds.  Lee mentioned that these powders would be of a fine grain size than the soft pastel dust, and much more dense in opacity, and not filled with binder material, such as calcium carbonate that is typically used in soft pastels.

This suggestion really caught my attention and imagination.  My initial thinking being that these powders would be like using a sledge hammer to swat a fly if I wasn't careful.  But, these could also be the answer to the brilliance problem I had encountered.

I just had to get my hands on some of this stuff!!!

And thankfully, my local art store is very well stocked, and carries both of these powder pigments.  I picked up a little tub of the titanium dioxide as the zinc dioxide is a little more translucent.





So to test the new powder, I brought up a black and white image of the Lagoon nebula that closely resembled its appearance through a telescope.  I started the sketch as ususal with the pulverised soft pastel.  Once completed, I took to the central areas with the powdered pigment - the results were immediate!

Those areas that I struggled to achieve the desired brilliance now absolutely glow!




Compare with the sketch I did just a few weeks ago.  I was just not able to generate the same brilliance in the right hand lobe and the stripe of material beside the star cluster.




If you decide to use these powdered pigments, be aware that these colours are very brilliant due to their greater opacity compared to powdered soft pastels.  Start very sparingly with it as it is very easy to overdo the intensity of the white.

I can't wait to use this new tool out under the stars next time!

Alex.