A star in the guise of a comet

Hubble’s Variable nebula

Here is a sketch of NGC 2261, the Hubble’s variable nebula.

Some informations :

– Telescope : Dobson Lukehurst 495/2032, Pentax XW 7 mm (x290), no filter.
– Date : 30/10/06, 04:00 UT.
– Place : Nailly, Yonne, France.
– Sky : not transparent (lim. magnitude about 5,0) but with very good seeing.

A draft was made during the observation, then I made two sketches : one with the stars, the other with the nebula (on a white paper and with a lead pencil). Then, I scanned the two sketches and saved negative pictures. The picture with the nebula was colored in a light green. And finally, I added the two images.  The sketch is not perfect : the east side of the nebula was more luminous than the west side – it is not obvious in the sketch. But the color of the nebula seems (to me) well shown.

Bruno Salque

Here’s a link to a archived post on Astronomy Picture of the Day that discusses some of the fascinating aspects of Hubble’s variable nebula.

The shepard philosopher

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
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

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.

Galactic fetters

Markarian’s Chain of Galaxies

Markarian’s Chain of galaxies

Sketch was made on copy machine paper, A4 in size, with regular graphite pencil and blending stump. Conditions were good, transparency was excellent , limiting magnitude was 5.70 but seeing wasn’t that great. I used 8″ F6 dobson and 10.5mm Baader Hyperion Eyepiece. Magnification was 114x.

Vedran Vrhovac

70 million light years away, the sprawling Virgo Cluster is home to perhaps thousands of galaxies. In fact the Virgo cluster, despite it’s great distance, subtends an angle of about five full degrees in our sky, making it ten times larger than the angle the Moon subtends. Markarian’s Chain, beautifully rendered by Vedran, includes M84, M86 and M88 along with a host of smaller elliptical, spiral and irregular galaxies. Studies indicate that seven of the galaxies in the Chain actually move together at the same relative velocity.

Resplendent raptor

M16 Eagle nebula

M16 Eagle nebula

This nebula was drawn with graphite pencils on
white paper and then inversed after scanning.
The main field stars (until about magnitude 11)
was printed with a charting software and the
fainter stars and nebula were added during the
observation. It took about an hour to lay all the
details on paper.

17.5-inch dobsonian, F/4.5, 74 &125x, OIII filter
used for the fainter parts; 15/august/2004,
22h00UT, good transparency (visual limit of 6.31
in UMi); from La Clapière in the french alps at
an elevation of 1650m.

Yann Pothier

Radiant spectacle

The Sun with Sunspot groups 484,486, and 488

Today, March 2, 2007, the sunspot number is zero.

The sunspot number on October 28, 2003 was 238. An X-17 solar flare erupted that morning. Sunspot groups 484,486, and 488 were associated with Coronal Mass Ejections and auraural activity. The attached watercolor was based upon a white-light solar image captured with a 4″ refracting telescope, a white-light-solar filter, and a digital camera. The image of the sun with sunspots 484, 486, and 488 was processed in Photoshop and then printed. In a photocoping machine a transparancy was made. The transparancy was placed on an overhead projector and the projected image was traced and colored with watercolor pencils. Then, with a brush, water was added to the sunspots and to the remaining surface and background.

If the use of an “overhead projector” sounds like something from a school project, it was. Students at the A.R. Gould School in South Portland, Maine have used this process numerous times to document their observations.

… just a thought about tracing. In the late ’90s, I sent a cardboard-box camera obscura to Betty Edwards, the author of “Drawing on the Right Side of the Brain”. In her book she recommends that one should try to copy an image that is upside down; she suggests that that may allow the observer/drawer to see what is there and not what one expects to be there. In the camera obscura that I constructed, the image was projected upside down. In our conversations I asked her about the whether she thought tracing was drawing. She said that if two people were to trace the same thing that the finished drawings would be different, because drawing is about how we see things. (She also said that tracing allowed muscles to build muscle memory. I suppose that that is similar to practicing scales in music.)

John Stetson

Stellar spirit

Abell 33

Ghost of a dying star

In the western reaches of elongated Hydra, near the western border of Sextans you will find a ragged string of four stars ranging in magnitude from 6 to 8 aligned northeast to southwest located 1.7° south of 4th magnitude Iota Hydrae and 2.5° east of 5th magnitude Tau1 Hydrae (a fine, widely spaced double star). The third star from the west (and slightly out of line with the other three stars) is 7th magnitude HD 83535. This bluish-white star is superimposed on the edge of a ghostly planetary nebula known as Abell 33. My best view of this limpid pool of nebulosity was achieved with a 20mm Plössl (yielding a magnification of 45x) and an OIII filter. This setup revealed a small faint disk of tenuous nebulosity about 4½’ in diameter in contact with the 7th magnitude star on its southwest edge. The edges of the disk were reasonably sharp and the brightness faded gradually toward the darkened center. At other magnifications (both with and without the filter) the view was less distinct and the nebula became almost impossible to detect at magnifications above 60x. The 16th magnitude central star was not visible, but a trio of 13th magnitude stars (two of them a close pair) are perched on the northwestern edge of the nebula.

Abell 33 was discovered on Palomar Observatory Sky Survey plates by George O. Abell and published in the April 1966 Astrophysical Journal (Abell 1966). These nebulae, being very faint and of relatively large angular size are classified as ‘old’ or ‘evolved’ planetary nebulae. Observing the 86 objects in Abell’s catalogue constitutes one of the supreme observing challenges for amateur astronomers with large-aperture scopes; fortunately a few of them, including this one, are accessible in fairly modest equipment provided the observer has access to very dark skies and an OIII filter. Recent estimates place Abell 33 at a distance of about 1,100 light years from Earth (Phillips 2005), which implies an actual diameter of about 1.4 light years.

Subject: Abell 33 (PK 238+34.1)
Object Type: Planetary Nebula
Constellation: Hydra
Right Ascension (2000.0): 09h 39m 09.1s
Declination (2000.0): -02° 48′ 31″
Magnitude: 12.4n/15.7s
Diameter: 268″
Classification: 2b

Observer: Eric Graff
Location: Cuyamaca Mts., San Diego Co., California (4,000 ft. elevation)
Date & Time: 12 March 2007 at 04:30UT
Transparency: NELM 6.7, TLM ~14.1
Seeing: Pickering 5-6/10
Telescope: Parks Astrolight EQ6 (6″ f/6 Newtonian Reflector)
Eyepiece: 20mm Parks Gold Series Plössl (45x, 70′ TFoV)
Filter: Lumicon OIII Filter
Sketching Materials: #2 pencil, black ink, blending stump, 24# copy paper

Abell, George O. 1966. Properties of Some Old Planetary Nebulae. Astrophysical Journal. 144:259-279.
Philips, J.P. 2005. The distances of highly evolved planetary nebulae. Monthly Notices of the Royal Astronomical Society. 357:2:619-625.

A rose by any other name

Rosette Nebula

The Rossette nebula, NGC 2237-8, 46

Here is a challenging object. It was at the threshold of visibility for me and my gear. The nebulae was visible at a power of 12.5 (40mm EP) and at 19x (26mm EP). It vanished at any higher power!! The sketch was made with help of a lumicon UHC filter. But the most significant aid in detecting the ghostly glow was wobbling the scope left and right. The eye is more sensitive to moving ghosts than to steady
ones. As a result of the UHC filter, the fainter stars are lost. But I wanted to concentrate on the nebulae. The sketch was made in Photo-Paint, based on a raw pencil-sketch behind the scope. I hope you like the view.

Rony De Laet

Sketch data:

Date : March 9, 2007
Time : 21.00UT
Scope : Skywatcher 102/500
EP : 26mm SP
Power : 19x
FOV: 2.7°
Filter : Lumicon UHC
Seeing : 3/5
Transp. : 2.5/5
Sketch Orientation : N down, W left.

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%

A dark horse

A dark horse

The Horsehead nebula is among the most photographed denizens of the deep-sky. But it is rarely the subject of a visual observation, much less a sketch. I made this observation the night of January 20, 2006, almost ten years to the day after my first observation of this ellusive object. Formally designated Barnard 33 (B33), the Horsehead is a dark nebula seen in the foreground of the delicate emission nebula IC 434. The contrast between IC 434 and the Horsehead is quite subtle; like a whisper in the night. But as long as the sky darkness and transparency are good, a 6-inch aperture is up to the task of seeing the famous Horsehead. On this night, the view in my 18-inch Obsession was truly stunning. Even unfiltered, the inky black form of B33 was obvious at 109X (22-mm Nagler Type 4 w/ Paracorr). My sketch represents a combination of two views. The first was unfiltered to reveal as many field stars as possible. The second was with a Lumicon hydrogen-beta (H-beta) filter in place to record the full glory of the B33/IC 434 complex. The Horsehead cuts into IC 434 along the nebula’s eastern edge. It is distinctively darker than the surrounding sky, having a genuine inky blackness as if someone has carelessly left the tip of their quill too long against the sky. The back of the horse’s neck, head, brow, and snout are all discerned. Some 60 stars frame the view.

I used HB and 2B Staedtler Mars Lumograph graphite pencils to make the drawing on a sheet of white printer paper. Gentle rubbing with the tip of my right index finger lended softness to the background nebulosity.

Bill Ferris
Flagstaff, Arizona