Explanation of Website

(See also The Deep-Sky Observer, Quarterly Journal of the Webb Society, Issue 131, p. 1, 2003)

This website includes visual pencil drawings of 120 galaxies that were made during routine galaxy photometry runs from 1977-1984 at McDonald Observatory in West Texas and Siding Spring Observatory in New South Wales, Australia. The telescopes used were mostly the McDonald 30 and 36-inch reflectors and the Siding Spring 40-inch reflector. A few were made with the McDonald 82 and 107-inch telescopes. Most are original drawings made at the telescope during nonphotometric (partly cloudy) periods. Most of the observing nights had little or no moon. A few drawings are copies where the original was messy. All drawings were scanned with an HP ScanJet and prepared for the website using Adobe PhotoDeluxe. The images were processed to remove erasure marks and background defects, and to homogenize the backgrounds since two different scanning programs were used.

The drawings do not necessarily show all the details that could have been seen in these objects, given that conditions were not perfect. However, even though clouds affected these observations, the good locations of the observing sites mean the conditions were still probably better than many other observing sites at lower altitudes. Spiral structure can be easily lost to light pollution. Both McDonald Observatory and Siding Spring Observatory are high altitude sites far from lighted areas (at least in the late 70s and early 80s), and suffered virtually no light pollution.

The observations were made with large focal length eyepieces that gave magnifications of 300X, 360X, and 820X on the McDonald 30, 36, and 82-inch telescopes, and 520X on the Siding Spring 40-inch telescope. The images in the montages are within a factor of two on the scale of the original drawings. Some are slightly enlarged while others are smaller than the original images on the drawings. There is no indication given on any drawing of the directions of north and east. They would have to be compared with photographs to get this information.

What the Drawings Show

The drawings show many different kinds of features that are normal parts of the morphology of disk galaxies. In addition to the graceful spiral arms, the drawings show bars, inner rings, nuclear rings, dust lanes, "knots" (or OB associations), and in at least two cases (M33 and NGC 4449), a few individual massive stars. The effects of interactions are evident in a few cases. Galaxy morphology comes alive with dark skies and relatively small observatory class telescopes.

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