Astronomy Sketch of the Day – Page 271 – Drawings and sketches of an astronomical nature

A Brilliant Irony

Venus
Terrestrial Planet
By Eric Graff
Parks Astrolight EQ6 • 6″ f/6 Newtonian Reflector
7.5mm Parks Gold Series Plössl + 2x Barlow • 240x, 13′ FoV
30 September 2007 • 13:00-13:30 UT

It is somewhat ironic that the most brilliant planet in the sky is also the most challenging to observe. On 30 September 2007 Venus appears as a dazzling crescent (32% illuminated) in the morning sky, 42° west of the Sun and shining at magnitude –4.7.

This observation was made during morning twilight and the white cloud-tops of Venus displayed a fair amount of subtle, dusky shading, seemingly in a series of roughly parallel arcs curving northward. The shadings were most prominent toward the terminator, while the polar-regions were quite bright, particularly the southern cusp. In spite of the atmospheric subtlety, I found the observation of the large Venusian disk quite relaxing and relatively easy compared to the previous observation of the tiny Martian disk.

Holmes in a Spin

Comet 17/P Holmes
28th October 2007
18:40 UT Mag 2
Reflector FL 1200mm/8mm eyepiece/150X Pastel/Conte/Black Paper

Here is my sketch from October 28th, I got going early to avoid the predicted cloud cover. I had a long look into the halo around the nucleus. The material emanating from the pin point center seemed to be heading in a more southerly direction than I had observed in previous evenings. I could see darker areas fanning in the opposite direction in the inner halo. A star was visible just inside the outer halo. Because I could see a star through the out gassing then it must be very thin? The star was visually similar in size to the comet nucleus but a little dimmer. Sometimes the coma seemed to momentarily have transparent spaces within it. I have not seen a star in the area of the dark spaces, I wonder if these spaces are filled with dust?

All this was visible even though there was a 17 day moon rising almost directly under the icy action.

Deirdre Kelleghan
President
Irish Astronomical Society 1937 – 2007
Public Relations Officer IFAS
http://www.deirdrekelleghan.com/
http://homepage.eircom.net/~irishas/index.htm
http://www.irishastronomy.org/

Walther’s Ray of Sunshine

Sunset Ray on the Floor of Walther

Crater Walther (formerly known as Walter) lies on the southern lunar highland’s great peninsula facing almost directly toward the earth. This is an ancient land, high, heavily bombarded and Walther is a Necterian age, 145 kilometer member. This walled-plain crater has tall terraced walls that tower 4 kilometers above the crater floor. The off center central peak stands 1.6 kilometers above the surrounding floor. The ancient rim is heavily cratered and has several incisura along its circumference created by impacts. Before sunset and at just the right time light penetrates through a notch in the western rim and sprays light across the floor to the central peak and several floor crater rims beyond in an eastward direction. The remainder of the floor is completely dark creating the frozen searchlight view that I attempted to capture in this sketch. West of the notched wall is crater Deslandres W with its large rim blocks which separates it from the hellplain, Deslandres to the west. Walther also has a sunrise ray that can be seen beyond first quarter at just the right time.

The following webpage gives the times of lunar ray events for craters including Walther. http://www.lunar-occultations.com/rlo/rays/rays.htm

Sketching:

For this sketch I used: black Strathmore 400 Artagain paper, 8”x 8”, white and black Conte’pastel pencils and a blending stump. Brightness was slightly decreased after scanning.
Telescope: 10 inch f/ 5.7 Dobsonian and 6mm eyepiece 241x
Date: 11-2-2007 11:40-12:40 UT
Temperature: 0°C (32°F)
Clear, calm
Seeing: Antoniadi III
Co longitude: 115.4°
Lunation: 22.3 days
Illumination: 43.6 %

Frank McCabe

Note to visitors: Frank dedicated this stunning sketch to Rich Handy last week in the Cloudy Nights sketching forum. Thank you Frank. I’m sure we all echo your wish that Rich have a speedy rebuild and return home.

Jeremy

A Cluster on the Doorstep of the Trifid

M21
By Wade Corbei

This is an Open Cluster found in Sagittarius that contains a lot of stars of varying magnitudes, and lies close to M20 (Trifid Nebula). According to my notes, this OC was completed over the course of two evenings due in part to its location in the sky. It slipped behind some trees to my south on the first night, so I had to finish the sketch the following evening. Total sketching time at the EP was, I believe, approximately 1.5 hours.

A nice OC that fills up the entire FOV in a low-power EP.

An Equestrian Prom

This is a sequence of the large prominence on the NW limb. I was so mesmerized by it that I wish I could have spent the entire day observing it. If you look closely, you can see a prancing Arabian horse in the prominence.

I used black Strathmore Artagain paper with a combination of white Conte’ pencil for the brighter, more dramatic areas and white Prang pencil for the fainter, whispy areas. I softened the black background in Photoshop to try and erase the splotchiness of the black paper as it took away from the faintest sections of the prominences.

Erika

The Eye of the Coppery Orb

Mars
Terrestrial Planet
By Eric Graff
Parks Astrolight EQ6 • 6″ f/6 Newtonian Reflector
7.5mm Parks Gold Series Plössl + 2x Barlow • 240x, 13′ FoV
30 September 2007 • 12:30-13:00 UT

The December 2007 opposition of Mars will pale in comparison to the very favorable oppositions of 2003 and 2005, achieving a maximum angular diameter of 15.9″ on 18 December 2007. On the other hand, it will not appear this large again until the opposition of 2016; also, unlike the previous two favorable oppositions, the Red Planet rides high over the northern crest of the ecliptic, placing it nearly overhead as it crosses the meridian for northern hemisphere observers.

On 30 September 2007, the Martian disk measures a mere 9.6″ and still shows a strong gibbous phase (the disk is 87% illuminated). The central meridian (CM) at the time of observation was approximately 110°. The principal Martian surface features identified during this observation include the dusky circular feature Solis Lacus drifting toward the terminator and the dark band of Mare Sirenum emerging from the limb. The Tharsis plateau, home of Mars’ mighty shield volcanoes occupies the relatively featureless golden plain near the center of the disk. Bright patches were detectable in the vicinity of both the north and south poles; I’m not sure whether these are the actual polar ice caps or “polar hoods” which are atmospheric mists associated with the evaporation of the caps. A few other patches of haze were detected around the southern limb.

A Fiddle on the Lake of Time

On October 30, site administrator, Rich Handy, lost his home to a fire. He and his family are ok, but as you can imagine he has a lot to deal with right now. Please keep him in your thoughts during this very difficult time. Until Rich feels ready to return to administering the site, I’ll do my best to keep things going. I’ve updated the submission page to include an email address to which I have access.

Rich has been very conscientious about not posting any of his own sketches here. I think this is an appropriate opportunity to dedicate the November 1, 2007 Astronomy Sketch of the Day to one of his many excellent Lunar sketches.

Hang in there Rich, we’re all pulling for you,

Jeremy Perez

Here are Rich’s notes about the beautiful surroundings of Hainzel, Hainzel A and Hainzel C:

In the south western quadrant of the Moon, amidst the heavily bombarded highland terra and adjacent to Lacus Timoris (the poetically named “Lake of Time”), lies the trio of complex overlapping craters, Hainzel, Hainzel A and C. A quick look at this grouping in this lighting may leave one with the mistaken impression that these three are the result of a single asteriod that broke into a couple of major chunks just prior to impact, resulting in the elongate structure without an obvious wall separating the two larger impacts. Despite that appearance, however, each crater was formed at a different epoch.

78 km Hainzel which comprises a good portion of the southern portion of the “fiddle” shaped complex, is a Nectarian era feature, formed sometime between 3,920 and 3,850 million years ago. In my sketch you can see that indeed, the lower crater has taken several impacts to it’s rim. In contrast, 38 km Haizel A above it, is a relatively youthful Erastosthenian era crater formed between 3,200 and 1,100 million years ago. Here again its youth can be gaged by the very fresh looking glacis, shown in my sketch as the ropey and branching area to the upper right of Hainzel A’s rim (the upper body of the fiddle). The drawing shows few superposed craters over this large area, a definite indicator of freshness. 19 km by 28 km Hainzel C is an Imbrium era crater formed during the gap in time between Hainzel and Hainzel A’s appearance between about 3,800 million and 3,200 million years ago. The light was not favorable for a good look at C, covered as much as it it was by deep shadow from it’s bigger brothers. Hainzel C is superposed on Hainzel. Previous views of C showed a damaged and disrupted floor and walls, most probably the result of the impact of A.

Here are the sketch details:

Subject: Hainzel, Hainzel A and C Rukl: 63
Date: 10-2-06 Time: 4:24 UT-5:43 UT
Seeing: Antoniadi III-IV Weather clear, light breeze
Lunation: 10.65 days Phase: 55.7 deg Colongitude: 39.5 deg
Illumination: 78.2%
Lib in Lat: +4 deg 55 min Lib. in Long: -5 deg 11 min
Telescope: 12″ Meade SCT, f/10
Binoviewers: W.O. Bino-P with 1.6X Nose piece
Eyepieces: 12.4 mm Meade series 4000 Super Plossls
Magnification: 393X
Sketch medium: White and black Conte’ Crayon on black
textured Strathmore paper.
Sketch size: 18″ x 24″

Floor Fractured Crater: Furnerius

Just two days past full moon, floor fractured crater Furnerius (125 km.) was well
placed relative to the sunset terminator to show off its interesting features.
This crater is one of the four large walled plain craters along the 60° E.
longitude line. Furnerius is the southern most of the four and placed not far from
the southeastern lunar limb. The other three which were visible at the eyepiece
from south to north but not sketched here are Petavius, Vendelinus and Langrenus.
Crater Furnerius is a pre-Nectarian crater and thus very ancient. It predates the
formation of the Nectaris basin. Basin debris and secondary impacts are scattered
across the floor and rim of this old battered crater. On the north side of the
crater floor a rille of 50 kilometers called Rima Furnerius can be seen. It
crosses the floor to the southeast and climbs the inner crater rim. Darker
smoother lava flooded areas can be seen on parts of the crater floor between the
rubble strewn regions created
by the basin impact. Inner wall terraces and central peaks are completely absent
from this crater but large crater Furnerius B(22 km.) is clearly visible on the
floor. On the glacis of this crater to the north a bright young 12 km. crater
called Fernerius A can be viewed in line with Rima Furnerius. To the northwest a 75
km. Copernican era crater Stevinus, stands impressively with its sharp rim, central
mountain peak and low hills. South of Furnerius a smaller yet equally ancient
crater Fraunhofer (57 km.) was showing a dark flat half shadowed floor. On the
northwestern rim of this crater Fraunhofer V (24 km.) could be identified by a
small sliver of light striking its inner southeast rim.

Sketching:

For this sketch I used: black Strathmore 400 Artagain paper, 9”x12”, white and
black Conte’pastel pencils and a blending stump. Brightness was slightly decreased
after scanning.

Telescope: 10 inch f/ 5.7 Dobsonian and 6mm eyepiece 241x
Date: 10-28-2007 6:05-7:45 UT
Temperature: 0.7°C (33°F)
Clear, calm
Seeing: Antoniadi III- IV mostly poor
Co longitude: 115.4°
Lunation: 17 days
Illumination: 93.7 %

Frank McCabe

Outburst of Comet Holmes

Many veteran comet observers regard the outburst of Comet Holmes (17P)
as one of the oddest sights they have seen. Not only was the sudden
brightening unprecedented in modern times, but the perspective we have
of this distant comet gave it an appearance all its own. From night to
night you can see it growing in size and yet, due to the dimming of the
expanding coma, it maintains a fairly constant brightness when viewed
naked eye.

Initially, the first images of this comet online indicate that is
difficult to capture the visual appearance with our imaging technology
and sketching is proving to be a satisfactory way to convey the visual
perspective at the eyepiece. I quickly opted for the sketching option,
but soon found that I had trouble getting a perfectly round coma that
also conveyed the contrasty ‘pop’ that this comet presented that first
night after announcement of the outburst. So instead of just using
image processing programs to get my onscreen-sketch looking like my
on-paper sketch, I decided to try to do more than embellish it and do
the sketch entirely with the image processing program. I refer to this
as digi-sketching.

So here is a series three ‘sketches’. The first is my original ‘paper
sketch’ captured and rendered to reflect what I had on paper. It was
graphite on paper with the colour added digitally.   It was
disappointing to me in that the brightness, contrast and the colourful
‘pop’ factor of this weird sight in northern Perseus was not entirely
captured.   The second sketch is my digi-sketch version of that same
night based on my original sketch. I soon appreciated that I could
quickly and easily correct some failings of the original.   The third
sketch is from three days later and is done to the same scale showing
the dramatic changes that took place in this short span of time. The
image processing program that I used for teh last two images is a PC
version of iPhoto that came with an old scanner. This makes me wonder
what is possible with some of the newer and more capable image
processing programs.

All three sketches were done from my view through a 12.5 inch home-made
Dobsonian using a Discovery mirror.   Binoviewers 23mm eyepieces and a
2x barlow gave a magnification of something well over 250x.    The first
two sketches are a result of my observations on the night of October
24th at around 10:45 CDT (UT 3:45 Oct 25th 2007).   The third sketch was
done on October 27 CDT at 11 PM (UT 4:00 on Oct. 28th 2007).   Note the
two 11th magnitude stars that could be seen shining through a relatively
colourless coma in this third sketch (bottom/south part of the coma
about 1/4 the way in). Since the equipment is constant for both nights,
the images can be directly compared for size and this gives one an idea
of just how quickly this comet grew in size.

This has to be one of the oddest and most unusual events in comet watching.

Gerry Smerchanski

Approaching Sunset at Posidonius Crater

On this night I watched the sunset terminator move slowly toward ring-plain crater
Posidonius while I sketched the crater and nearby features on the floor of 750 km.
diameter Mare Serenitatis. Posidonius (99km.) is an old upper Imbrian era impact
reminant. Its age is betrayed by the way shadows penetrate the rim at numerous
points as the sun continued to set. The highest part of the rim is on the
terminator side of this crater. Sunlight was still reaching part of Posidonius A
and two other high points on ridges including one on the inner ring. Beyond this
crater to the west and south the great serpentine ridge could be seen in best
light. This ridge is made up of dorsa Smirnov and dorsa Lister just north of
crater Plinius (44 km.). Smaller and younger crater Dawes (19km.) could be seen
casting a shadow eastward which was growing in length throughout the sketch
interval.

Sketching:

2H graphite pencil, black felt tip marker on white copy paper, gum eraser
Date: 12-10-2006 8:05 to 8:40 UT
10 inch f / 5.7 Dobsonian 9mm ortho ocular 161X
Temperature: 3°C (37° F)
Clear, calm
Antoniadi: III-IV
Colongitude: 150.1°
Lunation: 19.4 days
Illumination: 71.2 %

Frank McCabe