Astronomy Sketch of the Day – Page 264 – Drawings and sketches of an astronomical nature

Celestial Scarab

After a couple days off from observing the comet, I was treated to more stunning views. The Moon was out of the sky, and Holmes was really showing its stuff. To the naked eye, it is a soft puff in Perseus. Through 15 x 70 binoculars, it is simply awesome, floating brightly amid a rich star field. Color is now hard to describe, but I think it looks like the most subtle aqua color. Through the telescope, it is wonderfully bright, and loaded with soft detail. The subtle outer halo makes the comet appear even brighter than it is, as though the radiance of the coma is lighting up its surroundings. The outer halo appears brighter to me along the southwest side. The coma sports a well-defined northeast side with a diffuse southwest edge. Its edges have a hairy appearance that looks like it is being blown gently to the southwest. Within the coma, the central condensation now looks detached from the pseudonucleus. Some very subtle radial features began to coalesce after 45 minutes of observing at 120X and 240X. I don’t know if these are real structures, or just the cometary version of Martian canals. A brighter jet seemed to connect the now faint pseudonucleus with the detached condensation.

My measurements with the astrometric eyepiece are as follows:

Central Condensation: 92 arc seconds / 1.5 arc minutes
Coma: 653 arc seconds / 10.9 arc minutes
Outer Halo: 1550 arc seconds / 25.8 arc minutes

Subject 17P / Holmes
Classification Comet
Position* 6:15 UT – Perseus: [RA: 03:45:52.4 / Dec: +50:32:29]
Size Central condensation: 92 arc seconds / 1.5 arc minutes
Coma: 653 arc seconds / 10.9 arc minutes
Outer halo: 1550 arc seconds / 25.8 arc minutes
Brightness* ~ 2.6 vMag
Date/Time October 31, 2007, 10:00 – 11:30 PM
(November, 2007, 05:00 – 06:30 UT)
Observing Loc. Flagstaff, AZ – Home
Instrument Orion XT8 (203 mm dia./1200 mm F/L)
Eyepieces/Mag. 25 mm Sirius Plössl (48X)
10 mm Sirius Plössl +/- 2X Barlow (120X/240X)
12 mm Meade Astrometric +/- 2X Barlow (~100X/200X)
Conditions Clear, calm
Seeing 3/10 Pickering
Transparency ~ Mag 5.8 NELM
*Sources Aerith.net; Starry Night Pro Plus 5
*Based on published data.

Partial View of the Heart

A partial view of the Heart Nebula, IC 1805
By Rony De Laet

While IC 1848 appears as a distinct glow in the eye-piece, IC 1805 is a more difficult object to frame. IC 1805 is too large for my lowest power eye-piece. And the background is filled with starglow, competing with the subtle glow of the nebulosity of IC 1805. It’s hard to tell where the nebula dominates the glow. I decided to center the Northern part of IC in the EP. Why? Because I found the starfield with NGC 1027 an attractive area. NGC 896 just fell on the border of of my fov. Therefore it remained invisible to my eye. It occurs to me that I should return my gaze to this interesting piece of sky to capture the Southern part of IC 1805. Funny thing is that I reconned that my little scope would provide plenty of fov for large objects. And then I ran into an object like IC 1805. Maybe some bino’s might fill in the task in the future. Here is the sketch. (I must point out that not all the ‘glow’ represented in the sketch has a nebulous origin.)

Date : January 2, 2008
Time : around 21.00UT
Scope : Skywatcher 102/500
Eyepiece : Meade SP 26mm
Power : x20
FOV: 150′
Filter : Lumicon UHC
Seeing : 3/5
Transp. : 3/5
Nelm : 4.9 with moments of 5.2
Sketch Orientation : N up, W right.
Digital sketch made with PhotoPaint, based on a raw pencil sketch.

A Winter Evening Moon

A Winter Evening Moon
By Frank McCabe

After a very long spell of overcast nights, the clouds parted long enough for a
sketch of the winter crescent moon.

In the afternoon as the moon appeared high on the meridian from behind the clouds;
I put my 107 mm reflector telescope outside to reach temperature equilibrium. As
twilight began I got started. Using a 203 mm diameter protractor template, I drew
a white circle on black paper to represent the lunar disk. I then added a small
amount of Conte’ crayon powder and blended it inside the circle with my fingers
like a mirror maker adding fine grinding abrasive and water to a mirror tool. I
turned on the equatorial platform drive and now I was ready to observe the moon
and sketch.

This sketch is more of an impression of the moon rather than an attempt to achieve
a level of accuracy. The earthshine was nicely visible and since only 20% of the
lunar side facing the earth was illuminated the sketch was 5 times easier to do
than the full moon.

Sketching:

For this sketch I used: black Strathmore 400 Artagain paper, 12”x 12”, white and
black Conte’pastel pencils and a blending stump. Brightness was slightly decreased
after scanning.

Telescope: 4.25 inch f/6 Dobsonian and 24mm eyepiece 27x
Date: 1-12-2008 22:50-23:55 UT
Temperature: 0°C (32°F)
clear, calm
Seeing: Antoniadi III
Co longitude: 328.8°
Lunation: 4.5days
Illumination: 20.4 %

A Speedy Reputation

Comet 8P/Tuttle
By Michael Rosolina

Comet 8P/Tuttle is a periodic comet that comes by our little corner of the solar
system every 13.6 years. It was first discovered by Pierre Mechain 1790 but then
lost, not to be found again until Horace Tuttle spotted it in 1858.

This apparition is a particularly favorable one with Tuttle passing close to the
Earth–closest approach was 23.5 million miles/37.8 million km on January 1st. By
the end of December, Tuttle had brightened to about magnitude 6, putting it at the
threshold of vision for sharp-eyed observers with dark skies.

Because of its nearness to Earth, Tuttle lives up to the speedy reputation that the
word comet invokes. At the time of this sketch, it was covering about 4 degrees of
arc every day as it moved rapidly south through the constellation Pisces into Cetus.
I have included Tuttle’s position at the start of my observation to give some
sense of the distance it traveled in less than an hour.

The sketch was done at the eyepiece on Strathmore 400 series medium weight recycled
sketch paper. I used an HB pencil and a loaded stump and blended with my fingers.
After scanning I inverted the sketch digitally.

Semiannual Lunar Ritual

Vallis Schröteri and environs
By Jeremy Perez

And so, in the spirit of completing one Lunar sketch and observation every 6 months or so, I present Vallis Schröteri. On the night I made this observation, I was very impressed by the rugged terrain in the vicinity of this sinuous rille. The whole area looked like a badly skinned knee in merciful shades of gray. Although Vallis Schröteri was the celebrity, a few other features played staring roles. Mons Herodotus shone brilliantly while the craters Herodotus and Aristarchus stared out like spectacled eyes with the teardrop of Väisälä glistening on the burnished cheek of a nearby highland. Further to the north, Montes Agricola embraced the region like the tip of a rattlesnake’s tail.

There was so much to observe and sketch, I couldn’t possibly capture it all. I did learn from my previous attempts at white on black Conté sketching and went for a larger illustration. This sketch was prepared on a 9″ x 12″ sheet of black Canson Mi Tientes pastel paper. I used a blending stump to smooth the pastel where appropriate and to build up brighter tones. The brightest rims are straight attacks with the Conté pencil. The sketch took about 45 minutes at the eyepiece with another 15 minutes of additional touch-up indoors. White on black sketching is really a great way to tackle the moon–especially the terminator. I hope to keep working at it when time permits. I’ll still be using pencil and charcoal, but it’s nice to have this method accessible when I want it.

Object Information:

Vallis Schröteri is the largest sinuous valley on the Moon. Although hidden in shadow in my sketch, this valley makes its start at a 6 km diameter crater just north of Herodotus crater and widens to 10 km. This area is sometimes referred to as the Cobra’s head. It then winds 160 km and narrows to 500 m at it’s end. The rille is likely the result of volcanic activity as a lava flow carved its winding path through the landscape. Aristarchus is a remarkably bright crater with a pronounced ray system. It is 40 km in diameter and is believed to be a relatively young 450 million years old.

Subject Vallis Schröteri and Surroundings
Classification Sinuous Valley, Craters and Mountains
Position West
Phase/Age 11.7 Days
Size* Vallis Schröteri: 160 km length x 1000 m depth (max)
Herodotus: 35 km dia
Aristarchus: 40 km dia x 3000 m depth
Väisälä: 8 km dia
Dorsum Niggli: 50 km length
Montes Agricola: 160 km length
Mons Herodotus: 5 km dia

Date/Time April 28, 2007, 10:00 PM MST (April 29, 2007, 05:00 UT)
Observing Loc. Flagstaff, AZ – Home
Instrument Orion SVP 6LT Reflector (150 mm dia./1200 mm F/L)
Eyepieces/Mag. 10 mm + 2X Barlow (240X)
Conditions Partly cloudy, calm
Seeing Ant. III
Sources Atlas of the Moon by Antonín Rükl 2004; Observing the Moon by Gerald North 2000.
* Based on published data.

Stellar Reflection

M78, a reflection nebula in Orion
By Wade V. Corbei

After trying more than once, I finally was able to get a good night of dark skies and good seeing in order to observe M78, a Reflection Nebula in Orion last month.

Although fairly unspectacular overall, there is a rich starfield that helped in enhancing the overall view of this nebula through the EP. I did notice, with averted vision, that quite a few of the stars that surround this nebula contained some color…from slight blueish-white to a rusty orange/red. The colors, although slight, add a nice contrast in the EP FOV.

Eastern Limb Arrival

NOAA 10980 arrival on Eastern Limb
By Erika Rix

2007 12 31

Solar

NOAA 10980 arrival on Eastern Limb

Erika Rix

There were a few events of activity on the Eastern limb that day and it was reported
by Spaceweather.com that a C8 class flare “hurled a “bright CME into space.”

Gary Palmer had an excellent animation on the site the next day if you haven’t seen
it yet. www.spaceweather.com

Evidently excitement started about 0110 UTC. I observed from about 1850 UT – 2005
UT. The following sketches reflect that observation period.

Here is the animation I created with my sequence of sketches of the Eastern limb. It
lasted from 1900 UT – 2000 UT.

Sketch Media:

Black Strathmore Artagain paper

White Conte’ Crayon and pencil

White Prang pencil

Charcoal

White vinyl eraser

Scanned in Photoshop, adjustments made on contrast and brightness as well as
cleaning stray marks

Animation created in Animation Shop

A Winter Trip to California

NGC 1499, The California Nebula
By Rony De Laet

Hello all,

Another challenging object suggested by Sue French is the California Nebula. The object has been imaged very often, mostly with an H-Alpha filter. I tried several times from within my backyard to locate NGC1499 visually with my four inch scope. With the H-Alpha images in mind, I expected to see an obvious streak of light in the eyepiece. Of course, my nelm 5.2 sky did not offer me such a view. At home, I suspected some nebulosity North of Xi Persei. I wondered what the Alpine sky would reveil of NGC 1499. My findings were at first dissapointing. I saw the same nebulosity as from my backyard, only did it show up more obvious. The way NGC 1499 appears to me visually would not inspire me to call it a California shape. Nevertheless is NGC 1499 a very interesting object for the patient observer. I estimated the Nelm in Austria (Bisschofshofen) that night around mag 5.7. A better sky would offer a more detailed view for sure. Here is my impression.

Date : December 27, 2007
Time : around 17.30UT
Scope : Skywatcher 102/500
Eyepiece : Meade SP 26mm
Power : x20
FOV: 150′
Filter : Lumicon UHC
Seeing : 4/5
Transp. : 4/5
Nelm : 5.7
Elevation : 800m ASL
Sketch Orientation : N up, W right.
Digital sketch made with PhotoPaint, based on a raw pencil sketch.

Sunken Yet Uplifted

The lunar crater Posidonius
By Frank McCabe

Posidonius on the Eastern Shore of the Sea of Serenity

On this cold morning in early December the most eye-catching crater resting on the
concave sloping rim of Mare Serenitatis was 96 kilometer diameter Posidonius. The
Posidonius cratering event likely occurred 150 thousand years or more after
Serenitatis formed a ring basin. The subsequent floor uplift and fracturing within
Posidonius created a large angular block and ridge margin that you can see arching
parallel along and just inside the outer eastern crater rim. At 17.5 days into the
lunation, the floor of Posidonius appeared much brighter than the dark margin lava
of Serenity. Eleven kilometer crater A near the center of Posidinius was clearly
visible in the poor seeing as were craters B, J, and M arching out from the rim to
the north. Beyond these craters encircled by the Lake of Dreams is 25 by 30 km.
oval “island crater” Daniell, formed by a shallow angle impact before the greater
Posidonius event took place. South from Posidonius and again along the shore of
Serenity is the 63 km. flooded crater LeMonnier. Nearly all of the west rim of this
tilted crater and its floor are covered by the dark margin lava of the Sea of
Serenity.

Sketching:

2H graphite pencil on 5 x 8 inch index card
Date: 12-8-2006 11:30 to 12:15 UT
Temperature: -14 °C (6° F)
clear, cold winds
Pickering scale: 3/10
10 inch f / 5.7 Dobsonian 161X
Colongitude:127.5°
Lunation: 17.6 days
Illumination: 86.3 %

Frank McCabe

The Many Faces of Mars

Mars opposition 2007-2008
By Kris Smet

I started observing Mars early in July to make the most of the opposition in
December when the planet’s disk reached almost 16“. However the first few sketches
may not look like much, I believe making the sketches helped me gain more experience
over the months. Putting the colour of mars on paper was much harder than I thought
it would be, I’ve tried a few different colours but kept changing them because I
wasn’t completely happy with it. The last sketch in my opinion looks most as how
mars appears to my eye in the scope. (All sketches were done with my 8” f/5
reflector on equatorial mount btw, I didn’t took the tube from the dobson base until
October though.)

All sketches are made outside sitting at the scope, with plain A4 printer-paper on a
clipboard on my lap. After the scope is brought back inside I work the sketch out
with colours and scan them in on my computer. The only ‘processing’ I (sometimes) do
is adjusting the brightness and sharpness levels a bit to look a bit more
eyepiece-like.

If you look very closely you can see the small disappearing south polar cap on the
first 5 sketches, after that I couldn’t detect it anymore. During September and the first part of October the north polar hood appeared bluish to me, but it seemed to disappeared and on the 14 October sketch the hood doesn’t show any blue.

While Mars was showing me it’s so called ‘boring side’ during September and October
(accept 5/10 & 31/10) I had the impression that the area south of mare Sirenum,
Cimmerium and Mare Tyrrherium was brighter and more yellow than the desert plains
laying south of them.

In December I had some very good views of the Syrtis Major region in which I could
see some detail. I had to wait until early 2008 to get my first view of the Solis
Lacus region, because whenever this side was facing earth I was clouded out :p

I hope to get more viewing time during January, February and perhaps March to make
another ‘collage’ of Mars sketches.