Crater Mersenius

Crater Mersenius

Crater Mersenius
Sketch and Details by Frank McCabe

Mersenius is an 84 kilometer diameter floor fractured crater just to the west of Mare Humorum. This crater is a Nectarian period crater estimated to be 3.9 billion years old. Close examination shows it has a very noticeable convex floor which is estimated to be half a kilometer higher than the floor edge. No hint of any central peaks seemed to be visible. The floor of this crater is fractured and one of those rilles appearing as a fine bright line was in view when the seeing was at its best just a few times as I sketched. Lunar geologists suggest that the bulging floor is due to lava upwelling from basin lava (Humorum), which released molten rock through the floor fractures at the crater’s center. This may account for the burial of the central peaks and production of numerous rilles. The floor distance below the crater rim is about 2.5 kilometers. Parts of the Rimae Mersenius system stood out clearly northeast of Mersenius Other craters included in my sketch are Mersenius D to the southeast, P to the north, 34 and 42 kilometers in diameter respectively. This was a most enjoyable sketching session because of the seeing and weather conditions.

Sketching:

For this sketch I used: black Strathmore 400 Artagain paper 8”x11”, white and black Conte’ pastel pencils and a blending stump. After scanning, Brightness was decreased (-4) and contrast increased (+2) using Microsoft Office Picture Manager.

Telescope: 10 inch f/ 5.7 Dobsonian 6mm eyepieces 241x
Date: 10-12-2008, 1:00 – 2:45 UT
Temperature: 16° C (61° F)
clear, calm, humid
Seeing: Antoniadi III, II
Colongitude: 60.4 °
Lunation: 12.7 days
Illumination: 90.6 %

Frank McCabe

Jupiter and Satellites

Jupiter and Satellites

Jupiter, Io and Europa
Sketch and Details by Carlos Hernandez

I made an observation of Jupiter on August 3, 2008 using my 9-inch F/13.5 Maksutov-Cassegrain. Much detail was noted over the planet, especially the South Equatorial Belt (SEB) and Great Red Spot (GRS). The seeing conditions were above average (6/10) for a short time before the clouds came in and ended my observing session. I welcome any comments that you may have on my observation.

Date (U.T.): August 3, 2008
Time (U.T.): 05:00
L1 016.2, L2 179.5, L3 177.6
Diameter (Equatorial): 46.4″
Instrument: 9-inch (23-cm) F/13.5 Maksutov-Cassegrain
Magnification: 273x
Seeing (1-10): 6, Antoniadi (I-V): III
Transparency (1-6): 5

Notes:
South Polar Region (SPR): Appears dark to dusky (3-4) and mottled.
South Temperate Zone (STZ): Appears thin and shaded to bright (6-7/10).
South Temperate Belt (STB): Appears dark (3/10) and thin. No ovals visible within it.
South Tropical Zone STrZ): Appears bright (7/10) with a dark (3/10), oval-shaped albedo feature following the central meridian (CM) and preceding the Great Red Spot (GRS).
Great Red Spot (GRS): Appeared dusky (3/10) and salmon-pink with a white central core.
South Equatorial Belt (SEB): Appeared dark to dusky (3-4) and containing dark (3/10) dark condensations along it’s northern border and bright (7/10) undulating sections (strips) within it.
Equatorial Zone (EZ): Appeared shaded to bright (6-7/10) with a thin, dusky (4/10) band across the center of it.
North Equatorial Belt (NEB): Appeared dark (3/10) and thin with a dark rod (barge) on the CM along it’s northern border.
North Tropical Zone (NTrZ): Appeared bright (7/10), but no other detail visible within it.
North Polar Region (NPR): Appeared dark to dusky (3-4/10) and mottled.

The Bay of Rainbows

Sinus Iridum

Sinus Iridum
Sketch and Details by Richard Handy

Less than a several hundred thousand years after the impact that formed the Imbrium basin about 3.8 billion years ago, the 260 km Upper Imbrian crater formed that would eventually become known to observers as Sinus Iridum, the poetically named Bay of Rainbows. In a blindingly intense blast lasting less than a couple of seconds, the roughly 13 km Iridum asteriod gouged out a section of one of the ejecta rings that surrounded the Imbrium basin, scattering a rubbly circular lens of debris around the crater. It’s floor was lower in depth to the south, where it intersected the plate shaped lowlands of the basin. Huge chuncks of ejecta covered or partially obliterated the older craters that had survived the Imbrium event, giving Nectarian aged 48 km Maupertuis on it’s northeast slopes an odd rhomboidal shape. Thirty seven km Lower Imbrium La Condamine to the north seems to have faired a little better, partially filled with Iridum ejecta. 24 km Bouguer to its west is the the most recent, of Copernician age. To the northwest it pushed up the rim creating the Jura mountains, in places 6000 meters high. Even though the Imbrium basin had been flooding for a few hundred thousand years, and the mare basalts had not yet reached the lower elevations of the southern rim of the Iridum crater, it seems likely that Iridum’s floor had already been weeping a slow flow of lava from fissures that had been opened up by the force of the fiery impact. Still it would be close to half a billion years before the Imbrium flows began to erode the southern peaks and cascade down the slopes to completely cover the crater floor. As the lower southern floor began to subside from the load of dense basalt, the whole southern rim section may have suffered a series of catastrophic slides further down into the Imbrium basin, producing the clean separation at the 2600 meter high Promontorium Laplace, the eastern cape. Now only the sinuous dorsae near the craterlet Laplace A mark the rim’s southern boundry. To the west, the Promontorium Heraclides, Cassini’s aptly named “Moon Maiden”, reaches a height of 1700 meters, yet the western cape seems to taper to the southwest, blending rather smoothly into the mare. Along with its slow liquid inundation, Iridum was struck by several small impacts, most notably 39 km Upper Imbrian Bianchini which apparently caused a section of the northern rim to collapse, creating a talus of regolith beneath it’s southern rampart as a result of the seismic shock imparted so close to the rim of Iridum. Beyond the capes to the southwest are the 26 km Imbrium aged crater Helicon and it’s smaller companion, 20 km Eratosthenian Le Verrier. Out on the mare, to the west of Promontorium Laplace, is Montes Recti, a rectangular group of mountains 94 km long x 12 km wide, at 1800 meters, towering over the surrounding somber lava plains.

Sketch details:

Subject: Sinus Iridum #14 of L100 Rukl: 2, 3, 10 , 11
Time: 4:47 UT till 6:10 UT Date: July 25, 2007
Seeing: Antoniadi III -II Weather: clear and calm
Lunation: 10.7 days
Colongitude: 35.8 deg.
Illumination: 76.8%
Lib. in Lat.: +07 deg. 31 min.
Lib. in Long.: -03 deg. 28 min.
Phase: 57.6 deg.
Telescope: 12″ Meade SCT f/10
Binoviewer: W.O. Bino-P with 1.6X nosepiece
45 deg. W.O. erect image diagonal
Eyepieces: 18mm W.O. Plossls
Magnification: 271X
Sketch Medium: White and black Conte’ crayon on black textured Strathmore paper
Sketch size: 18″ X 24″

Merope’s Brilliant Pedestal

M45

M45 – The Pleiades
Sketch and Details by Rony De Laet

M45 is perhaps the most attractive open cluster for binoculars. It certainly is best viewed with a low power instrument. At a distance of 410 l-y this admirable open cluster still measures 2 full degrees across. Its true diameter is 14 l-y. M45 is with an age of 20 million years a relative young cluster, so young that the dinosaurs never saw Pleiades. Charles Messier included the cluster as the final entry of his first catalogue. Some say that Messier just added the Pleiades to arrive at 45 objects in total. M45 is a very rewarding object in any aperture. The tiny dipper can also be seen with the naked eye. It’s a fun exercise to count the number of stars visible with the naked eye. And do compare the Pleiades with the other great cluster: the Hyades. Keep in mind that the Hyades are 150 l-y away, while the Pleiades are 3 times further away. With the two clusters in your line of sight, the night sky suddenly shows a greater sense of depth, doesn’t it?
An interesting fact is offered by the nebulosity associated with the Pleiades. According to recent research, the open cluster is just passing through a nebulous cloud in the Milky Way. Photographs show this nebulosity very well. The visual observer must make use of the clearest nights to see a glimpse of this faint haziness. The brightest part of this nebula is NGC 1435, also called the Merope or Temple’s Nebula. Look for a faint comet tail S of Merope. I saw NGC 1435 with a 4” refractor before, so I knew where to look. Much to my surprise, I could detect the Merope Nebula with the 15×70. There is also a small ‘stripe’ of light visible just N of Merope. This small portion of NGC 1435 runs from SE to NW. The trick is to make the best of your averted vision while trying to avoid the bright glare from Merope.
I usually have little sense of colour. But when I studied this beautiful cluster, I compared its members with the surrounding field stars. While I swept the white looking Pleiades out of the field of view, the new field stars looked pale yellow to me. When I switched back to M45, the cluster suddenly looked rather blue. I repeated this exercise several times to convince myself that M45 does look bluer than the surrounding stars.

Site : Le Castellard Melan, France ( 44° N )
Date : September 29, 2008
Time : around 0.00UT
Binoculars : TS Marine 15×70
FOV: 4.4°
Filter : none
Mount : Trico Machine Sky Window
Seeing : 2/5
Transp. : 4/5
Sky brightness : 21.33 magnitudes per square arc second near zenith (SQM reading).
Nelm: 6.5
Sketch Orientation: N up, W right.
Digital sketch made with Corel Paint Shop Pro X2, based on a raw pencil sketch.

(Note: if the sketch does look too dark on your monitor, try to darken the room.)

Globular Cluster – M2

M2

M2
Sketch and details by Wade V. Corbei

Here is a sketch from back in August. As how I am blessed with clouds and rain, I thought I’d go through my sketchbook and start to catch up on digitizing some of my sketches.

This Globular is actually quite a treat in the EP, it is bright, compact and stars resolve fairly easily. Although not as spectacular as M13 or M15, this Globular nonetheless is quite a sight for those who enjoy looking at a gazillion stars crammed into a relatively small space.

The background stars set this Globular off quite nicely.

Crater Longomontanus in Early Morning

Crater Longomontanus

Crater Longomontanus
Sketch and Details by Frank McCabe

Over the past few weeks clear skies and good seeing have been absent at my usual observing site. Last evening all that changed at sundown with good clearing of the heavy cloud cover. As the moon moved eastward against the background stars and entered Capricornus, it was high enough in my sky for close examination and sketching. Among the craters of the southern highlands just at the terminator margin was walled plain crater Longomontanus (155 km. in diameter) basking in the early morning sunshine. This ancient impact is an old worn Nectarian period formation with a younger floor formed by liquefied eject from the formation of one of the distant large basins such as Orientale or Imbrium (see LPOD, December 30, 2007, C. Wood). Immediately east of Longomontanus I was able to see what remains of smaller older Longomontanus Z (95 km.). It is the darker shadowed depression that is only partly visible. The floor of this crater has small, mostly buried, central peaks which were casting long shadows on to the western inner crater wall. One of the three craters, Longomontanus L (16 km.) on the western floor stood out nicely in the grazing sunlight at the margin of the crater floor shadow to the north.

Sketching:

For this sketch I used: black Strathmore 400 Artagain paper 8”x11”, white and black Conte’ pastel pencils and a blending stump. After scanning, Brightness was decreased (-3) and contrast increased (+3) using Microsoft Office Picture Manager.

Telescope: 10 inch f/ 5.7 Dobsonian and 9 mm and 6mm eyepieces 161x, 241x
Date: 10-9-2008, 0:10 – 2:15 UT
Temperature: 10° C (50° F)
clear, calm, humid
Seeing: Antoniadi III
Colongitude: 23.4 °
Lunation: 9.7 days
Illumination: 65.9 %

Frank McCabe

North America Nebula

NGC 7000

NGC 7000 – The North America Nebula
Sketch and Details by Juha Ojanperä

Object name: NGC 7000, North America nebula
Object type: Bright nebula
Location: Parainen, Finland
Date: 9/10.10.2008
Instrument: Lens 80mm/400mm (3” lens)
Medium used: Graphite pencils and cottonwool sticks
Observing conditions: Dark, clear sky
Notes: Very large bright nebula. The distinct shape of the nebula is pretty easy to see, after some gazing and with aid of O III filter. In the North America, Mexico and the area around Gulf of Mexico are brightest, though the eastern coast is also considerably bright. The nebula gets fainter to the north and west. The Pelican nebula appeared as faint, nebulous patch a little bit to east from the eastern coast.

Celestial Lollypop

M3

M3
Sketch and Details by Jeff Young

While I suppose the bent stem looks more like a flower, M3 has always struck me as a fuzzy lollypop. However, I’ve attempted to render it as accurately as possible, without colouring the image with any impressions I might have gleaned, so that you can form your own, unique impressions.

M3 (NGC5272); globular cluster in Canes Venatici
sketched 4/31/2008 in County Louth, Ireland
as viewed through 16” Mak-Cass @ 150X; Pickering 8, NELM 5.5, SQM 20.6

My globular sketching technique is a bit different from that I use on other DSOs. I first place as many brighter stars as I can stomach using a medium-soft (HB) pencil. This sketch has about 120 placed stars, most of them in the globular itself. I then lightly smudge the image with a blending stick to show the extent of un-resolved stars. Finally, I place a harder pencil (3H) vertically on the drawing and rotate it slightly to form each of the smaller stars. These are placed randomly to reproduce the levels of shading I see in the eyepiece.

The sketch is then scanned into Photoshop and inverted.

Learning from NOAA 11003

Solar - AR 11003

Solar NOAA 11003
Sketch and Details by Erika Rix

2008 Oct 05
Solar – featuring SE quadrant and NOAA 11003
Erika Rix, PCW Memorial Observatory, 40.01/-81.56
Observation details:

AR 11003 was not visible to me in white light using my ETX70 with a TV8mm plossl. I did see granulation on and off, transparency isn’t too great today. I almost thought I detected this region briefly, but couldn’t confirm it.

In h-alpha using my Maxscope, the area was lit up very nicely by bright slender plage making some of the background around it appear darker in comparison to the rest of the disk. I didn’t see any sunspots within the active region.

There were many prominences scattered around the limb and a very short, almost spot-like filament in the southern hemisphere west of the AR.
Sketch details:

This case is a perfect example of getting carried away with fitting in all the details and then losing touch on size and contrast. The active region was smaller in real life and a little further away from the limb. I continued on with the sketch anyway, marking the error in my report and off to the side of the sketch, since it was still an accurate representation of the AR within itself.

The prominence set on the limb is accurate in size, but I rendered it too bright, again getting carried away with my markings while trying to mark in the details within the prom.

Even though I’ve made the errors, I’ve marked them accordingly and still have a successful sketch from my observation. I say successful because I’ve still achieved my goals of in depth study of the Sun through sketching and managing to record my observations of these features regardless of two areas of errors that I stated. Sometimes sketching can be like patting your head and rubbing your belly at the same time. The results can make you giggle, but you still trying your hand at it.

I grabbed the black paper closest to me today, so that was the Artagain paper. White Conte’ chalk, Conte’ pencil, and white Prang pencil were for the white areas. Contrast added with a stick of charcoal and a black pen. No erasing was done and blending of the solar surface was done with my finger tips. No blending was done after that.

I added a -15 brightness after taking a photo of my sketch with my Rebel outside in diffused lighting. My new scanner is still giving me fits scanning in my sketches, so I find it easier to take photos of them until I can master the new machine. Taking a little more time out of my day than I should have for fun, I managed white light and h-alpha viewing.