Sketching Your Observations


Drawing Edge-on Galaxies

STEP 1: Anchor the Drawing

Galaxies are my favorite observing targets. I find the dichotomy of an unimaginable large object appearing supremely fragile compelling in the utmost. Also, these distant stellar gothams sometimes display a wealth of detail. Edge-on galaxies like M104 in Virgo, are recognizable by their distinctive dark lanes. To begin my sketch of M104, seven stars are drawn to anchor the field. The star closest to center is seen just a couple of arc minutes south of the galaxy core. The others provide a simple context for the observation.

STEP 2: The Galactic Disk

As usual, I begin my drawing of M104 by sketching the brightest visible features. These include the core of the galaxy and the southern edge of the galactic disk. It is common for edge-on galaxies to have these details appear brightest. Drawing these ffeatures, first, gives definition to the remainder of the galaxy.

STEP 3: The Dark Lane

Dark lanes are tricky. Many observers take the approach of erasing to create the lane. However, I feel the better approach is to draw the nebulosity around the lane, which avoids the challenge of having to erase to create that pencil-thin dark line. M104 is not perfectly edge-on. It is tilted at just 6 degrees but that's enough to make the northern half look much smaller in my 10-inch Newtonian. I draw the brightest portion as a small triangle directly opposite the southern core region. The gap between the two defines the width of the visible dark lane. I also add some nebulosity around the southern core. This renders the brightest portion of the central bulge.

STEP 4: Finishing

Up to this point, I've been observing the galaxy for 15 to 20 minutes. Dark adaptation is maximized and my eye has gotten to know M104 quite well. In finishing the sketch, I add more nebulosity to fill out the size of the galaxy as seen with averted vision. Smudges along the edge of the galactic disk and around the central bulge add the needed softness to the image. The bright edge of the disk is highlighted as is the stellar core region. Finally, stars are scaled to indicate relative brightness and a stellar metropolis comes to life.

Drawing Spiral Galaxies

STEP 1: Anchor the Drawing

Most of my sketches take about 20 minutes to complete. But there are objects which demand more attention and a longer committment. M101 in Ursa Major is among these. It is also a fine example of a large, open faced, spiral galaxy. I anchor the sketch with seven stars and the galaxy's stellar appearing core region. This large, low surface brightness galaxy requires significant attention and time before the full view is garnered. With such subjects, I'll often spend 10 or 15 minutes just observing, studying the object and allowing my dark adaptation to improve.

STEP 2: Spiral Structure

This requires patience and a delicate touch. Over the course of another 15 minutes or so, I rough out the visible spiral structure with extremely light brushes of the pencil against the paper. I want to add just enough lead to define the arms. Also, since I'm seeing just bits and pieces of spiral arms, I am careful to keep multiple segments of the same spiral arm in good alignment. I also draw the oval core region, which helps define the proper curvature for the spiral arms. Occasionally, I'll break from sketching to spend a few minutes just observing the field. I might add another faint star or two to help frame the view. Then, I'll return to roughing in the spiral arms.

STEP 3: The Galactic Disk

With the spiral structure roughed in, I turn my attention to the delicate glow of the galactic disk in which the arms are embedded. Using the finger smudge technique, I soften and smooth the arms. This also spreads lead to the disk. The prudent application of a few slight pencil strokes adds just enough lead to allow me to smudge in the remainder of the disk. The drawing is almost complete. I've been at it for nearly 45 minutes. After a short break to, again, just take in the view through the telescope, I'm ready to finish the sketch.

STEP 4: Finishing

One of the challenges preparing a sketch for public display is preserving the level of detail and the subtle contrasts of the original sketch. The best way to achieve total image fidelity is to display just the original. If I were a famous celebrity, perhaps thousands of amateur astronomers would be willing to travel to Flagstaff, Arizona, to see my sketches. But I'm not and they aren't. That's OK with me, I enjoy maintaining Cosmic Voyage and hearing from people all over the world who have visited my site. One of the compromises I've decided to just accept is that scanning my sketches results in images which do not fully preserve the quality of the originals. I say this to put the accompanying final image in context. In the original sketch, the galaxy appears significantly more subtle and the spiral structure is not nearly as obvious. Nevertheless, the image at left does present a reasonable facsimile of M101's appearance in my 10-inch Meade Newtonian.

The Deep Sky Star Clusters Emission Nebulae


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Revised: June 15, 2003 [WDF]