#261  
Old 31-07-2014, 06:20 PM
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mental4astro (Alexander)
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Polarissima Australis

This is one of the three sketches I managed to do at this year's Astrofest in Queensland.

While the northern sky has its distinct star Polaris, the Southern sky has no such similar beacon. The closest relatively bright star to the South Celestial Pole is Sigma Octanes, but it is a few degrees away, and is not a very bright star at all. There is one catalogued object that is actually closer to the SCP, a tiny magnitude 14 galaxy that has the beautiful name 'Polarissima Australis'. Yet despite having such a special place in the sky, and having its own distinct name, there are actually very few photos/images of NGC 2573.

I've been wanting to sketch this faint distant island universe since I first glimpsed it a few years ago. But it has proved to be very illusive. Being so faint and small, it demands good transparency to be seen otherwise its soft light just doesn't make it through to our instruments. At a distance of some 128million light years, it is not a surprise really. The very first time I spotted it, it was a much easier task. Other nights I looked for it, it was invisible, testament to poor transparency. This night it did reveal itself, it wasn't an easy exercise. Curiously though, I spotted two other fainter objects within the same field of view. While I've put them on the sketch, I've been struggling to gather any information about these two objects. I haven't been able to find anything at all about there being two faint fuzzies in the positions I've put these two on, even though other fellows during the night also spotted them, confirming my sightings.

It is not the most spectacular of objects in the sky. Far from it. But its special place in the heavens, and the challenge it presents to observe, certainly warrants its sketching.

Object: Polarissima Australis, NGC 2573
Telescope: 17.5" push-pull Karee dob
Gear: 13mm LVW, 154X
Location: Linville, Queensland, Australia
Date: 25th July, 2014
Media: Soft Pastel and white ink on A4 size black paper
Duration: approx 1/2hr.
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  #262  
Old 02-08-2014, 06:30 PM
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The Ink Spot - Light vs Dark

Hi all,

This was the first sketch I completed at Astrofest. I've been wanting to sketch this beautiful dark nebula ever since I first laid eye on it some three years ago. This dark nebula, B86, goes by the popular name of "The Ink Spot". It sits smack bang in the centre of the densest star cloud in the whole sky, the Cloud of Sagittarius. And what sets it off even more is B86 has a gorgeous bright open cluster right next to it, NGC 6570. Both objects are more-or-less the same size as each other, even though both are not very large themselves. But it is the juxtaposition of these two very different objects against the blaze of the Milky Way that makes this pair a spectacular pairing.

Dark nebulae are clouds of dust and gas that are drifting through the Milky Way galaxy. Many of these conglomerations of dust and gas do end up being formed into stars and planets, but most just end up forming the fabric of the galaxy. In fact, the stars that we see actually only form a small percentage of the actual mass of galaxies. By far the greatest amount of a galaxy's mass comes from this very dust and gas. The Ink Spot is a small patch of cloud. It is a very opaque nebula too. Dark nebulae are categorised according to their opacity, or how dark they are. The scale of opacity goes from 1 (very tenuous) through to 6 (very opaque). While the opacity of The Ink Spot may be a 5, it is because that it sits in the Cloud of Sagittarius that makes is a striking object.

The little open cluster NGC 6520 really works very well in setting off B86. Open clusters are groupings of stars that are all related to each other having been formed out of the same parent cloud of gas and dust. Evidence for this is seen in the spectra of the stars displaying the same chemical make up. The brothers and sisters of our own Sun have been identified this way, with the same chemical signature as our Sun having been identified in several close by stars even though the Sun's 'siblings' have long drifted off away from each other. Open clusters are loose groupings too, so even though they formed from the same source, their gravitational connection to each other is not strong enough to keep the group together for too long.

For me, this tiny patch of sky is one of my most favourite. Tiny and oh so precious. Brilliant, dark, stark, ghostly. All in one. Gorgeous.

Object: The Ink Spot, B86 & NGC 6570
Telescope: 17.5" push-pull Karee dob
Gear: 13mm LVW, 154X
Location: Linville, Queensland, Australia
Date: 24th July, 2014
Media: Soft pastel, charcoal and white ink on A4 size black paper.
Duration: approx. 3hrs
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  #263  
Old 02-08-2014, 08:24 PM
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Another cracker sketch Alex. I see you've even managed to fill in the thousands of backgrounds stars
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  #264  
Old 03-08-2014, 10:35 AM
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wow very nice Alex it does look like a pretty area that I havnt taken any notice of I must have a look at that one next time I get the scope out cheers
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  #265  
Old 14-08-2014, 06:38 AM
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M22 globular cluster

Thank you Sab and Jen.

Sab, the thousands of tiny background stars is something added in the cool light of day. Just pecking away with a sharp pencil, and constantly, again and again and again resharpening it. These tiny stars are not accurately portrayed unless there are specific concentrations I would have made a note in on the original sketch. It is the brighter and more significant patterns that can be laid down with some degree of accuracy. Same with M22 below. Most of the time spent on M22 is in the multitude of stars that are significant - and that is a bloody lot of them. But the tiniest pinpricks are added afterwards to give the necessary depth to the sketch.


This was the second sketch I completed at this year’s Astrofest.

M22 is a true jewel of the night sky. This giant globular cluster from a dark site it can be a naked eye object as well. It is large enough for even smaller telescopes to resolve its multitude of component stars, revealing its large and intense core.

M22 is beautiful in my 17.5” scope. It is very different from Omega Centauri and 47Tuc – could even describe it as the ‘runt’ of the giant globulars as its core is not as busy as its bigger brothers. But the component stars of its core are absolutely brilliant, arranged in so many signature patterns. It is slowly turning into a favourite of mine with its understated brilliance, loud without being overbearing presence, and sitting on a magnificent carpet of the Milky Way glow.

I won’t say much here. I’ll let M22 do its own quite whispering of its magnificence. Yeah, I think one firm fav of mine now…

Object: M22 globular cluster
Scope: 17.5” push-pull Karee dobsonian
Gear: 22mm LVW, 91X
Location: Linville, Queensland, Australia
Date: 24th July, 2014
Media: Soft pastel and white ink on A4 size black paper
Duration: approx. 2.5hrs
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  #266  
Old 14-08-2014, 10:01 PM
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Very nice Alex
when u say white ink what exactly are u using is it a white gel pen
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  #267  
Old 15-08-2014, 12:29 PM
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Quote:
Originally Posted by mental4astro View Post
Thank you Sab and Jen.

Sab, the thousands of tiny background stars is something added in the cool light of day. Just pecking away with a sharp pencil, and constantly, again and again and again resharpening it. These tiny stars are not accurately portrayed unless there are specific concentrations I would have made a note in on the original sketch. It is the brighter and more significant patterns that can be laid down with some degree of accuracy. Same with M22 below. Most of the time spent on M22 is in the multitude of stars that are significant - and that is a bloody lot of them. But the tiniest pinpricks are added afterwards to give the necessary depth to the sketch.

That makes sense, it would be quite a mission to plot them all 100% accurately!
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  #268  
Old 27-08-2014, 08:47 PM
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Another stunning pair of sketches Alex! Brilliant!
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  #269  
Old 29-08-2014, 05:27 PM
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Great sketch Alex. M22 was the first globular cluster to be discovered.
Abraham Ihle (Ilee) found it in 1665 from Germany.
Edmund Halley found the 2nd GC, omega Centauri from St Helena Island in 1677.
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  #270  
Old 25-09-2014, 10:36 AM
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Thank you Glen and Paddy for your words.

NGC 1566 - a gem sharing the sky with a colossus

I was given the rarest of all gifts a married man with an astro fetish can get on Monday - a free pass to make a dash to a dark sky!!! I didn't read the fine print that came with the pass, so I'll probably pay for it sooner or later...

Of the 'fresh' items I spied out that night, one was a complete revelation, the little Seyfert galaxy NGC 1566 in Dorado. I was inspired to chase it down by the recent SN that's been found in it. What I didn't expect was the absolute treasure that this galaxy is!!! OMG! Not only is it a pocket dynamo bright with easy arms to make out (I'm using a 17.5" dobbie), but one of the arms has its entire length lit up by beaded trail of massive stellar formation! What a cracker-jack galaxy!

I couldn't make out the supernova even though it was still visible this night. I just couldn't distinguish it from between 1566's bright core and the bright foreground star very close to the core.

You'll find a more complete write up on my blog site so I don't double up posts and threads: Galaxy NGC 1566 - a hidden treasure deep in the Southern Sky

Object: Galaxy NGC 1566
Telescope: 17.5" Karee push-pull dob
Gear: 10mm Pentax XW, 200X
Date: 23rd September, 2014
Location: Katoomba Airfield, NSW Australia
Media: Soft pastel & charcoal on A4 size black paper.
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  #271  
Old 25-09-2014, 10:54 AM
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Well done Alex, (1566) you have good eyes.
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  #272  
Old 25-09-2014, 08:21 PM
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That's a beauty, Alex. Well done (as usual!).

Cheers
John
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  #273  
Old 25-09-2014, 08:30 PM
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Awesome Alex
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  #274  
Old 29-09-2014, 11:58 AM
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Lagoon Nebula (M8)

I've been having a crack at some sketching with an HB and a shading stump, inverting the image in GIMP and slightly enhancing some of the brighter stars (a little whiter and rounder). Hope it looks something like it? I try not to reference the AP images. Still learning to trust averted vision for details so quite vague on that front.
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Old 29-09-2014, 12:02 PM
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Orion

Also had this sketch from last summer which was all about trying out the shading stump. Spent too much time trying to make it hazier!
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Old 29-09-2014, 12:06 PM
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Pleiades

Tried adding the diffraction spikes in this one. Clear skies.
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  #277  
Old 29-09-2014, 08:44 PM
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Well done Ben
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  #278  
Old 30-09-2014, 06:50 AM
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Nice work Ben. Great to see a few works!

Where were you when you did these sketches? Under dark skies or urban?

Diffraction spikes are great tool to add 'brilliance' to the brighter stars without making big dots. I use them too for this.

An HB pencil is a good start. Try going softer with graphite, 2B, 4B, even 8B. These will kick things along with the blending/shading stick. You might even like to explore things with charcoal too - very different beast to graphite.

One thing I do to develop technical ideas & also shake out cobwebs if I haven't done a sketch for some time is to sit down with a black and white astro photo & practice a bit. This way you can push techniques without fear of 'wrecking' a proper sketch done at the eyepiece. If something doesn't quite work, no harm done. If another starts tickling your fancy you can develop it some more. What a photo does is guide your eye to the forms, shapes & density variations that on your own we just can't do. Other times I find I don't need a photo, just working on a technique. Sometimes it is best to try things out in the light of day so you go to the eyepiece best prepared & not guessing.

last week I started a sketch of the Tarantula Nebula. So many folds in it. After 2 & a half hours I was not happy with it. Something just wasn't right. I started a practice piece at home to try a few things out. I spent about an hour 'doodling' until I came up with something that gave me the effects I was after. This last Saturday night I continued with this Tarantula piece, employing what I had sussed out at home. Much happier now with the piece,

Do a few practice pieces. It will embolden you at the eyepiece! You'll get a whole lot more out if you don't have to worry about what the pencil is doing.
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  #279  
Old 30-09-2014, 05:31 PM
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Thanks for the encouragement Jen and the great advice Alex. These sketches were done in urban skies, 7km south of the Brisbane CBD. The Lagoon was through a 12" Dob and the others were through an 8" Dob, neither of which are goto scopes. I enjoy the nudging in a way as it seems to bring out a little more detail. Hopefully I'll get a chance to try some daytime sketching but my doctoral studies (in music) tend to limit my time :-/ Thanks again and clear skies :-)
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  #280  
Old 30-09-2014, 06:38 PM
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You've done well to pull out this amount of detail in M8 under urban skies,

Ben, it is no accident that you actually DO see more by constantly nudging the scope along. While a go-to instrument will help find and track objects, it makes for 'lazy' observing. By that I mean it takes out the very thing that maximizes the sensitivity of the eye at low levels of light - movement! At these levels of light, our eyes are poor in sensitivity and so saturate quickly and we end up seeing less. Also, our eyes designed to respond to the slightest change in illumination - notice that you always quickly notice something move out of the corner of your eye? Again, no accident.

All this leads to one thing - you need to induce movement into the image you are looking at to re-set and refresh the maximum sensitivity of our eyes. Trick is that just by moving your eyes quickly about the FOV does not achieve this - we can't fool our eyes this way.

This is something that I've noticed over many, many years of observing, but it was only explained to me the mechanisms at play about 5 years ago. For this reason, all but one of my 7 scopes are not motorized. The only scope I have with a drive is my 30 year old C8 that I uses exclusively for the Moon and planets.

Take my last posted sketch of the little galaxy NGC 1566. It is a very small object with soft details. Yet even with averted vision, some of the faintest of details only had detailed features after the scope was given a little nudge. Once the scope was still, these features quickly faded out of view, only to pop up again with a little nudge of the scope.

Now, all is not lost with a go-to instrument. What is important to do to achieve this exact same movement induced re-activation of the eye's sentitivity is by giving the scope a good tap to induce a shake/vibration into the instrument. It is necessary to make this second nature otherwise it is something that is easy to forget to do - and you end up loosing so much of what the scope is actually providing.
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