Media Combinations – Page 40 – Astronomy Sketch of the Day

Between Serenity and Tranquility

Craters Plinius and Dawes

After more than 23 days of very cold, cloudy, winter weather an approaching warm front got me out under the moon and stars on this clear, transparent night of good seeing. I centered the telescope field of view on craters Plinius and Dawes near the lunar terminator. This is the region I selected for my sketching. Plinius is the largest (43km) crater in the sketch. Its central peak and irregular, cratered floor are hidden in darkness but a hint of its terraced walls can be seen on the illuminated inner west margin. Further to the west the peaks near Promontorium Archeruia are catching the rising sunrays. About 55 km to the south of Plinius is crater Ross, a 26 km diameter crater identified only by its sunlit rim. This crater rests in the Sea of Tranquility. To the northeast of Plinius near the edge of the Sea of Serenity is the 19 km crater Dawes, its floor mostly in shadow. Directly to the north of Plinius the rilles of Plinius were clearly visible. In addition a small part of Dorsum Nicol is also seen. All of these features are positioned on the dark colored lavas at the boundary between the two above mentioned seas. The grazing sunlight helped to enhance the changes in topography.

Frank McCabe

Sketch details:
For this sketch I used: black Strathmore 400 Artagain paper 9”x12”, white and
black Conte’ pastel pencils and a soft leather blending stump.
Telescope: 10 inch f/ 5.7 Dobsonian and 6 mm eyepiece
Date: 2-23-2007 1:05-1:45 UT
Temperature: 0C ( 32F)
Clear, calm
Seeing: Antoniadi II
Colongitude 339 degrees
Lunation 5.4 days
Illumination 35.7%

Fountains of the Sun

Ever-changing Proms

AR949 was not very apparent, but there may have been a hint of a few pores towards the center of the disk, slightly north of the “equator”. There were two long slender patches of plage near a fairly long (maybe 20 deg) filament in this region.

Along the limb, I noted 7 areas of prominences, with some scattered jets of “baby” proms spiking out here and there. Of the 7 areas, I initially concentrated on two, position angles of approximately 240 and 50 degrees. The area at the NE was very faint at first. I adjusted the front etalon to create more contrast. But come to find out, yes it was faint, but the sweet spot of this 60mm Maxscope seems to be just SW of center. I heard that these Maxscopes don’t have a sweet spot, but there is an obvious difference in the contrast depending on where your target is in the FOV with this scope. Still, it’s a beauty of a scope and I still can’t believe my good fortune in acquiring it.

The prominence to the SW was very sharp and prominent. Still, you can see the slight changes over a 30 minute time frame, making it an amazing site to behold. Like the Moon, you can’t spend a lot of time rendering the view. The terminator on the Moon changes before your eyes. Well I feel the Sun is even more dynamic, and the sketches last only minutes before the shapes take a different form.

Getting back to the NE prom, it was very fibrous and to me was lovelier than the SW area. Again, the changes are noted in a 30 minute time frame.

What ended up being my la proéminence du jour was a patch of nearly lunar terminator looking proms on the western limb. When the session began, this area was plain, with only a few little spikes with a finger pointing north. But about 45 minutes later, made me feel like I was observing the Moon again, just like it did the day I sketched this prominence.

AR946 had comma shaped plage surrounding the 2 sunspots within connected by a darker
strand. There was a filament about the same size located to the southern region of
the disk as well as plage just inside the limb about 30 degrees from the prominence
at PA 70 degrees.

2007 04 02, 1900-2000 UT
Zanesville, Ohio
Internally Double stacked Maxscope 60mm with 8mm TV plossl.
Seeing average with moments of heavy quivering. Transparency poor.
Temps 72 °F / 22.2 °C
Winds from West at 16 mph with gusts up to 28 mph, scattered clouds
31% Humidity Sketches were done with black Strathmore paper and colored Conte’ crayons.

Erika Rix

Entrance to a frozen Hell

There was a very thick mist that night, and the moon was hardly visible behind the clouds. I put the scope outside with no intent for observing, as I wanted to adjust a new home made focuser. It was a very pleasing surprise to discover that there was absolutely no turbulence at all on the Moon.
Despite the thick clouds, the light and contrasts were still strong, and everything was frozen, no movement at all. I jumped on my pencils, and made a draft of Eratosthenes, one of my favorite craters on the Moon, maybe my favorite. I like the long and thin design of the Apennine mountains terminating like a lyra, with that black and strange hole, just at the limit of infinite darkness.

Pierre Desvaux

– Medium used: White Conté on black Canson paper
– Telescope: Home made 16″ Dobson, Nagler 12, barlow 2X Celestron
– Date: December 2006
– Place: Blanzy, Bourgogne, France

Cold clouds

This large prominence was on the sun’s south west limb on March 27, ’07. Activity was otherwise low. Paradoxically, prominences are cooler than the surrounding atmosphere. They are columns of sun-stuff trapped and held up in the magnetic fields above the solar surface. The trapped plasma cools, recombines into hydrogen atoms and then emits visible light to show up as a prominence. The glowing gas twists and swirls in the sway of the magnetic fields and can change its appearance from minute to minute.

Observed from England at 10.30UT through a SolarMax60 H-alpha ‘scope at 50-80X, seeing moderately steady. The sketch was made large on A4 Canford black cartridge paper using white Derwent Studio and Derwent Watercolour pencils, the latter dry. I try to avoid erasers or blending stumps as they can sometimes take away the immediacy. If necessary, unwanted marks or brightness are reduced with lines of black Derwent Studio pencil. It is necessary to work fast and to finish a sketch within ten minutes, any longer and the scene can alter significantly. Details of this prominence were changing quickly but it was visible in more or less in the same overall form for over two days.

Les Cowley

Stop by and take a look around Les’s spendid daily website “Atmospheric Optics”. Click on the link in the blogroll.

Galactic swing dance

Object: Messier 51, The Whirlpool Galaxy
Classification: Galaxy
Position: RA 13h 29.9 min, DEC 47° 12′
Distance: ~23 million light years
Visual Brightness: 8m4
Apparent Dimension: 11′ x 7′
Constellation: Canes venatici
Observing Location: Erbendorf, Steinwald, Bavaria, Germany (800 meters
above sea level)
NELM: 6m2
Seeing: II / VI
Transparency: I-II / VI
Date: March 15, 2007
Instrument: Dobsonian 8″ f/6
Eyepiece: Reese 9mm Super Wide Angle
Magnification: 133x
Sketching Materials: black cardboard, white pastels, white ink, blending stump

A lot of work and patience went into the above drawing of M 51 to bring out as much detail and structure as possible: after one hour of dark adaption, another hour of pure observing and one more hour of sketching was invested, to get a glimpse of the subtle dark and light structures inside the diffuse nebulosity, which is generated by the object. At a first look, two blurry, bright smudges appear in the eyepiece, which can each be separated into a bright, almost stellar core surrounded by a diffuse, somewhat less brighter halo. It becomes apparent that the two objects are not located directly next to each other, but that there is a somewhat darker area in between, which is suddenly “cut off” by a brighter region in the east: the “bridge” of matter connecting the two galaxies! Inside M 51 A two slightly brighter regions start to appear, which bend away from the core and “dissolve” in the galactic disc: a hint of the spiral structure! Finally, two faint stars can be observed, which are apparently located East and West of the core, they are supposedly stars in the foreground. It may be noted here that the detail depicted in the drawing is the result of many hours of observation and patient use of averted vision, resulting in some sort of “sum picture”, which is surely not visible at a first glance. The beginner may be completely satisfied, if he can recognize the two discs and their cores – all the other details will appear with constant and regular observing.

Sebastian Lehner

To a southern exposure

Comet C/2006 P1 (McNaught)
10 January 2007 2255 UT
10×50 Binoculars
Cold Knob, WV USA
Altitude: ~3°
Conte’ Crayon on textured pastel paper

For me, getting a look at the famous Comet McNaught was not easy. I had tried and failed two days earlier at sunset when trees and houses blocked the view and it was rapidly sinking lower each evening–in a couple more days it would be gone for observers in the Northern Hemisphere.

Determined to see this comet before it disappeared, I trekked to the top of a nearby mountain to get a clear view of the western horizon and set up my binoculars. It had snowed 6 inches the night before, but now it was clear. Before the end of civil twilight, the comet popped into view. As the orange winter twilight progressed, McNaught took on the appearance of a burning ember just above the horizon.

The sketch is taken from a graphite pencil sketch I did in the field. The most notable features at 10x were the bifurcated tail extending about 30 arcminutes to the northeast and the very bright coma. The comet against the orange background of sunset was unforgettable. I have seen many images of McNaught in magazines and online that were taken on the evening of January 10th and they all show that orange winter sunset.

Of course, Comet McNaught went on south to become the brightest comet in 41 years, visible during daylight, and with a tail so long that it extended back to the northern hemisphere. But I saw it before it became famous.

Michael Rosolina

Pacific places amidst “magnificent desolation”

Distinctive crater Stofler resides in the midst of the dense and chaotic crater field of the southern hemisphere of the Moon. One clear but very chilly evening in January 2007, the challenge of trying to capture the view was more than I could resist – this is my attempt. The sketch was carried out using white and black Conte’ pencils and chalk pastels on black ‘Canford’ paper. I began by marking out the main crater shapes using white Conte’ pencil, then I used a small chunk of white chalk pastel, broadside, to lay down the mare regions, blending this with a fingertip and a small cloth. More highlights were added (white Conte’ pencil), and a putty eraser used to define some of the features (and shadow extent) by negative drawing where I removed areas of pastel previously laid down. More detail was added with white Conte’ pencil as I went along, but there really was far too much to capture and I realized that I would have to quit while I was ahead and finish my outside drawing time before the view changed substantially. Once back inside I tidied up the sketch, removing the inevitable unwanted pastel smudges with a putty eraser, and re-defining some of the darkened inner crater edges with black Conte’ pencil, then using blending stumps (with touches of both white and black chalk pastel) to make final tiny adjustments. The sketch has been inverted and rotated in paint shop pro to give the standard orientation.

Sally Russell

Date: 25 January 2007

Time: 21.10-22.00 UT

Equipment: 105mm AstroPhysics APO/bino-viewer (mag x60)

Lunation: 7.3 days, 48.7% illumination

Sketch size: 6″ x 8″

The southern highlands of the Moon are almost completely dominated by craters in the 20 to 100 km size range, randomly scattered about the region. One way to determine relative ages of craters is to note which overlay or superpose over other craters or features, and the crater that obliterates or partially modifies another crater is usually younger. It is this principle that is the foundation of a stratigraphic approach to understanding lunar geological history. In the lunar highlands there is no shortage of overlapping or partially modified craters, and as Sally points out this region is about as densely chaotic as any on the Moon. A careful look at her beautiful sketch also reveals one of the great unsolved mysteries of the Moon. Many craters have smooth flat floors and the adjacent surface topography between these craters is also relatively smooth. The big question is: what is responsible for these smooth areas? Do the smooth floors and intercrater terrane reflect episodes of highland volcanism? Or perhaps these areas are covered with thick layers of ejecta that settled out across the surface as a result of this large scale stochastical gardening.

The shepard philosopher

When I looked outside that Sunday evening there was not a cloud in the sky and the eight day moon was shining down on me from a very favourable angle. There were far too many desirable sketches available, and my eyes darted from Rupes Recta toward the south, to Eratosthens and the shadows and highlands spinning off it, and further north to Plato sitting on the darkness of the terminator. It was a difficult choice, but I settled on Plato just because it had slightly more interesting shadows and also some very bright highlights emerging from the darkness near its northern rim. A long thin pointed shadow poured from the base of Mons Pico toward the terminator and also from another high area to its right as I viewed it. These shadows lengthening in the hour it took to do this sketch. Just above Mons Pico as I viewed (south is up) a change in the lunar surface was apparent in the form of an Eiffel tower shaped greyness which swept up to and finished at Piazzi Smith. Mons Piton sits with Piazzi in area across from Montes Alpes which had several sun kissed high points. I observed the needle like Vallis Alpes cutting a sharp gash in the surface through rugged lunar land, lit slightly on its northern edge. Feathery shadows set of the shape of Plato and detached from its northern rim, very bright high areas warmed themselves as they became uncloaked from the blackness.

Deirdre Kelleghan
President
Irish Astronomical Society 1937 – 2007

Sketch details:

February 25th 2007
20:45UT – 21:45UT
53.2000ºN, 6.1000º W
200mm/F6/6.3mm Plossel/193X
8.19 days
Seeing 2
Trans Average
300gm Daler R paper/DR soft pastels/Black watercolour pencil/wooden toothpick
www.irishastrosoc.org

Plato and Sheep

Nestled on the plains between Mare Imbrium and Mare Frigoris lies the nearly lava filled crater Plato. This 100 km, dark pool of frozen lava has a darker tone than the lava that filled the Imbrium basin. Crater counts indicate that the lavas that filled Plato are actually younger than the Mare lavas of Imbrium. The history of emplacement goes something like this: the Imbrium basin was created first, followed by the impact that created Plato, and then the gradual fill in of basaltic lava that flooded Imbrium and much of the existing basin rings and superposed craters. This left untouched some of the isolated massifs that are now known as Plato’s Sheep, including the towering Montes Pico (2500 meters high), Piton (2000 meters high), and the Tenneriffe Mountains (2500 meters high). Finally came the slow lava inundation of Plato itself. Above Plato and rendered with wonderful precision is the Vallis Alpes, a large graben (extension) fault which probably formed as a result of the original impact that created Imbrium. Dee’s beautiful sketch clearly depicts the drama that awaits the observer when the telescope is turned to this region as the terminator passes through.

Famously floor fractured

$Famously floor fractured$

Lunar crater Petavius

The end of winter in the Midwest can sometimes produce cold, clear, wind free nights. On this particular night the waning gibbous Moon cleared the tall barren trees where I had set up my 10″ scope to observe and sketch. After examining the Moon awhile at low power I selected a target close to the terminator for sketching. Near the edge of the southeastern corner of the Sea of Fertility is the large ancient crater Petavius. Connected by a rampart to the west (just right of Petavius) is 57 km Wrottesley. To the east of Petavius buried deep in shadow is the Palitzsch Valley, asequence of overlapping craters that extends for nearly 112 km. The atmosphere was in such turmoil that much of the subtle detail was obscured at the time of this observation. The multiple mountain peaks on the floor of Petavius stood out as did the terraced walls and the 60 km long straight rille from the central peaks to the southwest rim. Even under conditions of poor seeing this is a rewarding crater to observe a couple of days past full Moon. If you missed it, try again 3 days past New Moon. From March to the end of spring the waxing crescent Moon is a great target in the Northern Hemisphere.

Frank McCabe

Sketch data:

For this sketch I used black Strathmore 400 Artagain paper 9″ x 12″, white and black Conte’ pastel pencils and a soft blending stump.

Telescope: 10 inch f/5.7 dobsonian and 6mm eyepiece

Date: 3-6-2007 2:45-3:30UT

Temperature: -6C (21 F) Clear Calm

Seeing: Antoniadi IV

Colongitude: 113.5 degrees

Lunation: 16.5 Days

Illumination: 95%