Namibia Globular

Globular clusters display distinct “personalities” to an attentive observer. Some
appear as pale, starless discs in large aperture telescopes while others, like Omega
Centauri, begin to resolve in small refractors. Less frequently, they will display
subtle color. My sketch of NGC 6388 in Scorpius is an example of this. Using the
Sossusvlei Mountain Lodge 12″ Schmidt-Cassegrain with a 31mm Nagler (~100x), the
globular’s star-like core appeared to be weakly yellow. The tint disappeared at
higher magnification (250X/12mm Nagler).

The original drawing was done at the eyepiece using a soft lead pencil. I prepared a
copy based on this drawing and my field notes. First, a “smudge” of graphite was
dotted with acrylic ink. A garden variety Bic pen with blue ink formed the core —
and when color inverted — captured my visual impression of the yellow color fairly
closely. The nucleus was then enhanced with Photoshop and the entire drawing blurred
to simulate the rather poor resolution caused by the seeing conditions.

Dave Riddle
Smyrna, Georgia USA