Moon

Moon

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.

Wednesday, 20 July 2016

Schickard & Bailly - ancient features prove most intriguing

Hello everyone,

Finally another break in this run of poor weather for a visit to the Moon.

And two consecutive nights too!

As things have transpired, the last few visits to the Moon for me have been close to the Full Moon phase.  Not a complaint, just an observation on the coincidence.  For me, ANY time I get with the Moon of late is welcome.

Both sketches I managed were of very ancient features on the Moon.  So both show their age with their own set of tell-tale features.  And each also offered different sets of features that made each appealing to work on.

The first piece was centred on the ancient crater Schickard.  Schickard is just about a ghost crater now.  Having being formed long ago when the Moon’s crust was thin, the impact saw most of the crater filled in with lava, leaving just the rim.  But today this rim has been just about totally obliterated from the thunderous shaking and jolts it has experienced over billions of years of subsequent impacts, shaking the rim to almost flat today, with just the flooded crater mostly intact.  Not really surprising though as the rim is essentially just pulverised material with no structural integrity, just like dry sand, and the flooded floor being pretty much just a solid lump of rock.

What is intriguing about Schickard is the patch-work nature of its flooded interior.  From its age, one would expect a uniform colouration of the fill material.  Weathering of the lunar surface happens as a result of solar wind reacting with the material on the lunar surface.  The darker the material, the older it is, as newer impacts throw up fresh, unweathered material.  This is why craters such as Tyco and Copernicus are so bright.  Over time, these too will lose their brilliance.

Yet the fill material of Schickard is varied in colouration.  And there is a clue to the reason for this variation in colour through the internal feature of Schickard 1, a volcano.

Volcanos inside craters is a common feature of ancient, flooded craters.  It tells of continued volcanic activity on the Moon long after the original impact opened the thin crust, and lava filled the hollow.  Schickard’s stained floor, and the volcanic dome, can only mean that there was a significant change in the composition of the lava over subsequent eruptions.  The change in composition then explains the difference in colouration as the solar wind reacts differently with different lava compounds.  Curiously too, Schickard 1, the volcano, is the single brightest feature inside Schickard.  Schickard1 is the bright spot just to the right of centre.

To the South of Schickard is a trio of craters that form a very interesting grouping.  What caught my eye about this grouping is the flooded floors of all three give the impression of being higher than the surrounding moonscape.  According to Virtual Moon Atlas, they are!

Object:  Crater Schickard and surrounds
Scope:  C8, 8” SCT
Gear:  8mm LVW, 250X
Date:  18th July, 2016
Location:  Sydney, Australia
Media:  Soft pastels, charcoal & white ink on A4 black paper.




Twenty two hours later I followed up the Schickard sketch with work of the largest crater on the Moon, Bailly.

What most attracted me to Bailly was the delicate shading and fine lines that riddled the entire circumference of the rim, internal and external.

Bailly sits on the western limb of the Moon.  The result being that it is very foreshortened, and the Moon’s libration altering the amount of foreshortening that is seen.  Its position on the limb is such that the Moon’s libration has Bailly come very close to but not quite disappearing behind the limb.

Bailly’s foreshortening provides for an exquisite range of delicate shading and details along the length of its rime.  And the damaged rim on ends of the major axis provide wonderful textures and curving lines as the adjacent moonscape and craters encroach on the rim of Bailly.

The moonscape in front of Bailly is oddly smooth, with a cluster of mid-sized craters providing textural variation.  Despite the similar size of these craters, the age of these craters varies greatly.  Some of these are flooded, while others have clear floors with central peaks.

Object:  Crater Bailly and surrounds
Scope:  C8, 8” SCT
Gear:  8mm LVW, 250X
Date:  18th July, 2016
Location:  Sydney, Australia
Media:  Soft pastels & charcoal on A4 black paper




These two pieces took over two hours each to complete.  A most satisfying few hours spent with the Moon.  I hope you enjoy these pieces too.


Alex.