More of the Southern Highlands

Southern Highlands

Lunar Southern Highlands
Sketch and Details by Frank McCabe

I have always found the southern highlands an interesting region of the moon to examine along the terminator. At the times of low sun the craters here take on more unique and individual identities than at higher illumination. On this observing and sketching night, I managed to examine and sketch five notable craters. From south to north along the terminator are Boguslawsky (98km.), crater Boussingault E ( 98km.) and Boussingault B (54km.). All over the southern highlands are numerous, ancient, worn, soft looking craters between 10 and 90 kilometers in diameter. Some of the craters in this region pre-date the formation of the major lunar basins. These craters look soft and dusty with smooth terraces and regolith slumping to the crater floors. Lunar geologist Donald Wilhelms speculated that the appearance of the craters here is caused mostly by fluidized ejecta and debris tumbling down the crater walls to the floor. He also believes that the craters in the region of the sketch are sitting on an ancient 650 kilometer basin that is all but destroyed save for pieces of rim here and there. The two craters further west from the terminator from south to north are Manzinus (98 km.) and Mutus (78 km.). Craters B and A, both about 16 km. in size, can be seen on the floor of Mutus.
As a target the moon proved to be a very enjoyable subject on this evening of observation and sketching.

Sketching:

For this sketch I used: black Strathmore 400 Artagain paper 10”x 8.5”, white and black Conte’ pastel pencils and a blending stump. After scanning, Brightness was decreased (-2) and contrast increased (+2) using Microsoft Office Picture Manager.

Telescope: 10 inch f/ 5.7 Dobsonian and 9 mm eyepiece 161x
Date: 9-18-2008, 4:05 – 5:30 UT
Temperature: 15° C (60° F)
clear, calm
Seeing: Antoniadi III
Colongitude 129.5 °
Lunation 18.4 days
Illumination 90 %

Frank McCabe

A Swarm within a Swarm

NGC 1502

NGC 1502 and Struve 485
Sketch and Details by Eric Graff

NGC 1502 and STF 485
Open Cluster and Multiple Star in Camelopardalis
Parks Astrolight EQ6 • 6″ f/6 Newtonian Reflector
7.5mm Parks Gold Series Plössl • 120x
Field of View 26′
31 December 2007 • 03:30-04:30 UT

Dangling off the southern end of Kemble’s Cascade, one the sky’s better-known asterisms, you will find the open cluster catalogued as NGC 1502. Easily visible, even at low magnifications, as an unmistakable glittering mass of stars, the cluster is dominated by a brilliant pair of 7th-magnitude snow-white suns separated by 18″ of arc in position angle 305°. These two are the principal members of the multiple star STF 485 (ADS 2984; CCDM 04078+6220).

Increasing the magnification brings better definition and resolution to NGC 1502. A 7.5mm G.S-5 Plössl yielding 120x provided the most pleasing view in my scope, and this was used in the sketch presented here. All of the cluster stars appear to be pure white (or nearly so). The brightest stars in the cluster are concentrated into a narrow east-west band of stars spanning the cluster’s 8′ diameter. Most of these are members of the STF 485 system.

The Catalogue of Components of Double and Multiple Stars (CCDM) lists 16 members for STF 485 with magnitudes ranging from 7 to 14; these are designated (A-P) as indicated on the inset. Components C, E, F, G and M are very challenging due to faintness (mags 11.9-14.1) and proximity to A and B; the remaining members are quite easy by comparison. Component B is also a variable star, designated SZ Camelopardalis. It is a Beta Lyrae-type eclipsing variable with a period of just under 2.7 days and a magnitude range from 7.00 to 7.29. While component A might seem like a convenient comparison star for making magnitude estimates of SZ, it is suspected of being variable as well, with an observed amplitude of about 0.1 magnitude. Components H, I and J are also catalogued separately as STF 484 (ADS 2982); components K and L are catalogued separately as Holmes 3 (ADS 2989).

William Herschel discovered NGC 1502 on November 3, 1787 with his 18.7-inch reflector. It is sometimes called the Golden Harp Cluster; it contains 63 member stars and lies 2,650 light years away in the direction of Camelopardalis. Its age is estimated at 5 million years.

Echo of Mirach’s Ghost

NGC 404

NGC 404 – Mirach’s Ghost
Sketch and Details by Dale Holt

Following Frank’s post of Mirach’s Ghost NGC 404 on Tues 16th I promised in my comments to follow in his footsteps when the sky cleared and sketch this interesting duo.
Last night with my 14″ and Watec 120N Video camera I did just that. With the gibbous Moon rising in the east, Jupiter low in the SW and the summer triangle high over head it was at last! a fine evening, but I needed to move fast before the ‘Ghost’ vanished in the light of the silvery moon.

It was fun to follow what Frank had accomplished so recently.

Telescope 350mm F5 Newtonian reflector on a driven mount
Watec 120N Deep Sky B&W video camera fitted with an 0.6x Atik focal reducer.
The sketch made in real time from b&w security monitor on white cartridge paper using black ink for stars, HB pencil and blending stump for NGC 404 and diffraction spikes.
The sketch was scanned and converted into a negative image in photoshop

Dale Holt, Chippingdale observatory, Chipping, Hertfordshire, England

If Ptolemy Had Binoculars

M7

M7 – Ptolemy’s Cluster
Sketch and Details by Carlos Hernandez

I made an observation of M7 (Ptolemy’s Cluster, NGC 6475) in Scorpius on August 10, 2008 (03:00 U.T.). This is a spectacular open cluster, along with M6, located near the tail of Scorpius. On a clear night this cluster may be seen visually as a small “nebula” near the tail of Scorpius, as described by Ptolemy in 130 AD (“nebula following the sting of Scorpius”). Eighty stars brighter than tenth magnitude occupy a region of 1.3 degrees. The cluster lies at a distance between 800 to 1,000 light years. One of the finest open clusters (or any object at that) in the visible in the heavens.

Links;
http://www.hawastsoc.org/deepsky/maps/sco/sco1.gif
http://www.seds.org/messier/m/m007.html
http://apod.nasa.gov/apod/ap050406.html

A digital image produced using Photoshop CS3.

Carlos

Disrupting the Cygnus Star Cloud

NGC 6871

NGC 6871
Sketch and Details by Rony De Laet

On a dark summer night, the Milky Way itself is a magnificent deep-sky object for the naked eye observer. The subtle glow of the star clouds and nebulae offers an intriguing sight. One of the brighter clouds, visible from my latitude, is the Cygnus Star Cloud. The sky between Albireo and Gamma Cygni appears like a glowing oval. An interesting feature is displayed by the star field just NE of Eta Cygni. The smooth Milky Way glow seems to be disrupted at that location, as it shows a mottled appearance to the unaided eye. The binocular view reveals a multitude of star associations. The brightest stars, beside Eta, are 27, 28 and 29 Cygni (see the labelled sketch). Some of the star associations are real clusters. Such is the case with NGC 6871, which appears like a 1 degree long star chain, starting S of 27 Cygni, and running first N and then NE through 27 Cygni at 28 Cygni. It is unclear to me where NGC 6871 actually ends. A nice double star, called Beta440, can be found just S of 27 Cygni.
A small cluster, called Biurakan 1, can be found just E of Beta440.
Another cluster, NGC 6883 can be seen at 1° E of 27 Cygni. My pair of binocular just show NGC6883 as a small brightening in the Milky Way glow.
Another interesting star chain starts with 29 Cygni, which first runs S and then bends to the W and back to the N.
Many of these stars in this particular field are very young supergiants, and members of the Cygnus OB3 association, making part of the Orion-Cygnus Spiral Arm at a distance of 5.700 l-y.

Site : Bütgenbach, Belgium
Date : July 2, 2008
Time : around 00.30 UT
Binoculars : Bresser 8×56
FOV: 5.9°
Filter : none
Mount : Trico Machine Sky Window
Seeing : 3,5/5
Transp. : 4/5
Nelm : around 5.8
Sketch Orientation : N up, W right.
Digital sketch made with Photo Paint, based on a raw pencil sketch.

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

Crater Plato and Environs

Plato

Plato and Environs
Sketch and Details by Frank McCabe

One of the more famous features of the lunar surface is the walled plain crater Plato. This 100 kilometer crater was formed on the blocks of ejecta or the debris field (lunar Alps) of the Mare Imbrian basin forming event and it preceded the lava upwelling that flooded the floor of the crater and then the maria. Beyond the highland rise of the crater to the north is Mare Frigoris. To the west of the crater is Plato A a 22 km. crater beyond the ramparts of Plato. Just on to the smooth Imbrian lava to the south are the Teneriffe Mountains including Mount Pico at the east end of the chain. A portion of Rimae Plato was visible intermittently in among the rugged mountain bases of the Alps as seeing briefly reached average value now and again. The central peaks present at the time of the Plato impact are buried under 2 kilometer of lava and only small craterlets can be seen on the floor. Two of these were in and out of visibility as I drew this sketch. The rim on the shadowed side of the crater has irregular peaks that reach to 2.6 km. above the crater floor. At times of lower sun angles the irregular peaks cast long shadows that allow you to locate these summits.
In the years of the 17th century after the invention of the telescope, crater Plato changed names three times. In 1645 it was named Lacus Panciroli by Michael van Langren and in 1647 Johannes Hevelius named it Lacus Niger Major and finally Fr. John Baptist Riccioli in 1651 gave it the name we call it to this day.
If you have a telescope take a look at the crater floor and watch it change in brightness as we approach and then go past full moon. The moon is not light pollution it is a rewarding astronomical target.

Sketching:

For this sketch I used: black Strathmore 400 Artagain paper 10”x12”, white and black Conte’ pastel pencils and a blending stump. After scanning, Brightness was decreased (-2) and contrast increased (+2) using Microsoft Office Picture Manager.

Telescope: 10 inch f/ 5.7 Dobsonian and 9 mm eyepiece 161x
Date: 9-10-2008, 1:15 – 2:30 UT
Temperature: 15° C (60° F)
clear, calm
Seeing: Antoniadi III
Colongitude 29.6 °
Lunation 10.2 days
Illumination 72.7 %

Frank McCabe

The mysteries of Mons Rumker

Mons Rumker

Mons Rumker
Sketch and Details by Richard Handy

Mons Rumker sits in isolation on the dark basalts of northwest Oceanus Procellarum like a lonely sentinel on the edge of some vast undiscovered wilderness. The Rumker Hills dome complex, situated on the western flank of the Aristarchus Plateau, lies on the top of a local swelling that is about 140 km in diameter. It is composed of a remarkable set of about a dozen volcanic domes and low mounds, which are scattered in a rough semi-circular plateau approximately 70 km in diameter. The surficial domes apparently overlay preexisting low domes so that the elevated northwest sections have a pancake like appearance. Despite the long shadows when viewed close to the terminator, nowhere do these domes rise much above 500 meters in elevation from the mean surface of the mare. A central depression to the southeast of the domed crescent displays a strange dichotomy between its darker and lighter floor that is very reminiscent of areas on the Moon that have pyroclastic deposits. The mysteries of Rumker are manifold: why is this the only such layered dome field on the surface of the Moon? Why is located here? Does it predate the mare lavas or is it the representative of the last vestiges of differentiated magmas that ended the mare sequences in this area? Is the central depression part of a preexisting separate domain or were both aspects, both domes and depression deposits, created over the same period of time?

Sketch details

Subject: Mons Rumker and environs Rukl: 8
Date: 3-31-07
Session Start 8:03 UT End 9.48 UT
Seeing: Antoniadi II-III Weather clear
Lunation 1042, 12.3 days Phase: 25.2 deg Illumination 95.2%
Colongitude: 60.7 deg
Lib in Lat: +00 deg 05 min Lib. in Long: +04 deg 04 min
Telescope: Meade 12” SCT f/10
Binoviewer: W.O. Bino –P with 1.6X nosepiece
Eyepieces: 12.4 mm Meade Super Plossls
Magnification: 393X
Sketch medium: White Conte’ Crayon on black textured Strathmore paper
Sketch size: 18” x 24”

Spectacular Sombrero

M104

M104 – The Sombrero Galaxy
Sketch and details by Wade V. Corbei

Here is another sketch from a few months back that I recently finished digitizing, M104 The Sombrero Galaxy.

As far as galaxies go, M104 is quite bright and well resolved, with a very bright core and dark lanes that can be seen with averted vision. Even more spectacular when observing this galaxy is the fairly rich star field that surrounds the galaxy in the EP.

I will be revisiting this galaxy again when it is visible and try pumping up the magnification to re-sketch this great DSO.

Mare Crisium

Mare Crisium

Mare Crisium
Sketch and details by Dale Holt

Mare Crisium (the “sea of crises”) is a lunar crater located in the Moon’s Crisium basin, just northeast of Mare Tranquillitatis. This basin is of the Pre-Imbrian period, 4.55 to 3.85 billion years ago. This mare is 376 miles (605 km) in diameter, and 176,000 km2 in area. It has a very flat floor, with a ring of wrinkled ridge toward its outer boundaries. Ghost craters, craters that have largely been buried under deposits of other material, are located to the south.

The crater has many notable features in and around it. The cape-like feature protruding into the southeast of the mare is Promontorium Agarum. On the western rim of the mare is the palimpsest Yerkes. The crater Picard is located just to the east of Yerkes, and northwest of Picard is the crater Peirce. Mare Anguis can be seen northeast of Mare Crisium. Mare Crisium is the site of the Luna 15 crash in 1969.

I used my 150mm F9 Triplet refractor and Denkmeier binoviewer fitted with 32mm Plossl eyepieces to view this Mare.

I captured the image on black art paper approx 125mm x 125mm using a white Conte pastel, white ‘Derwent’ watercolour pencil, white ‘Derwent’ pastel pencil, black ink pen & blending stump.

The image was scanned and reorientated hopefully to match the description above description lifted from Wikipedia.

Date of Sketch 15-Sept-2008 20.15 UT

Seeing Ant III

Mag 98x

Moon phase 99.6%

Location: Chippingdale observatory, Chipping, Hertfordshire, England